BIKE SECURITY SYSTEMS

Transcription

1 BIKE SECURITY SYSTEMS APD Smee Anwar Diane Peters Esra Suel December 1, 006 Abstract This report demonstrates the strong need for a more robust, user friendly bicycle theft prevention system. National statistics on bicycle ownership and theft are included to validate this proposition, along with results from preliminary surveys. The current market has also been researched, indicating that consumers are not satisfied with current products. Design criteria are outlined for this project and several concepts are presented. One concept, based on the specified criteria, has been selected for development. Data from prototypes, engineering analysis, economic analysis, and marketing analysis is presented. Results of the project and future steps that could be taken are outlined.

2 Table of Contents Abstract... 1 Table of Contents... Introduction... 3 Problem Statement... 3 Previous Designs... 6 Design Objectives and Proposed Solution Preliminary Market Research Identification of Features to Include in Device Conceptual Design Concept Generation Concept A Concept B Initial Design Evaluation & Selection α Prototype Engineering Analysis Weight of the bottle: Relations between Cable Length, Spindle Diameter, Spindle Height & Cable Diameter19 Cable weight... 0 Weight of Spindle... 0 Weight of housing... 0 Total Weight... 0 β Prototype... Other Options & Future Enhancements... 3 Ergonomic Analysis... 4 Aesthetic Design... 4 Economic Analysis... 6 Product Demand... 6 Product Demand with Variable Design Attributes... 7 Revenue Equation... 9 Product Cost... 9 Fixed Costs... 9 Variable Costs Optimization Problem: Maximize Profit... 3 Marketing Analysis Market Size Functional Relationship & Logit Model Demand Function Linearization of the Marketing Demand Model Breakeven Analysis Product Design Process Broader Impact to Society Conclusion References Appendix A: QFD Matrix Appendix B: First Survey... 4 Appendix C: Engineering Model... 5 Appendix D: Economic Model Appendix E: Product Drawings and Bill of Materials... 54

3 Introduction Problem Statement In 001, the FBI reported approximately 90,000 cases for bicycle thefts across the 50 States. With the average stolen bike costing $318, the total estimated loss due to bicycle theft is a whopping $9.3 million 1. Furthermore, the National Bike Registry estimates that the FBI only hears about one-third of the actual stolen bicycle cases. Bicycle theft is a major problem, with seemingly little being done about it. Several underlying problems have led to this increase in bike theft, ranging from sheer human absentmindedness, to the lack of bike parking structures, to the vulnerabilities of current locking devices. A more robust, bicycle theft prevention and recovery system is needed to end this continuing trend. Consider the size of the bicycle market in U.S. as shown in Fig. 1: 1 Figure 1: Estimated US Bicycle Market $ Million Year This trend shows how the US market for bicycles has been steadily growing from 1997 on to 000. In 001, a slight drop was seen in bicycle sales due to the overall economic crisis the country was facing. The upward trend however is clear. What this means for us: With more and more bicycles being added to the market, the need for a more robust bicycle theft prevention and recovery system will also grow. Also, with more money being spent on buying the average bicycles, it is only expected that bike users will seek out locking devices that will represent the cost of their bike. Therefore consumers will be ready to pay for a theft prevention and recovery system that might cost a little more, but will outperform its competitors. 3

4 Figure : How satisfied bicycle users are with the safety in their local community biking environment % Very Satisfied Somewhat Satisfied Neither Satisfied, nor Dissatisfied Somewhat Dissatisfied Very Dissatisfied A survey was conducted to estimate how satisfied bicycle users were with the overall safety in their local community biking environment. Approximately 46% of those surveyed felt that their local community wasn t designed to make bike riding safe. What this means for us: Considering that 57 million people (above the age of 16) have had at least one bike in 00 1, and about half of these consumers aren t satisfied with the safety in their local biking community that leaves approximately 6 million bike riders nationwide as a potential market for a more robust theft prevention and recovery system. Figure 3: How much the Federal Government is spending to improve bicycling conditions 1. $450 $400 $350 $300 $ million $50 $00 $150 $100 $50 $ Year There is a steep upward trend that depicts how much money our Federal government is spending on improving cycling conditions. Data for the last reported years are especially interesting; where the spending went up by $77 million to over $416 million from the year 001 to 00. What this means for us: The government is stepping up to improve cycling conditions. This will include adding more cycle parking structures and improving cycling pathways. Both of 4

5 these will induce an increased number of cyclists, and inadvertently increase the opportunities for theft, therefore increasing the demand for a bicycle locking device. The beneficiaries for more robust bicycle theft prevention and recovery system go beyond simply the direct users. As cyclists will feel less concerned about bike theft, more users will be inclined to spend more money on bicycles, and bike more often. This will have a net positive national impact on many different levels: Economic benefits: Bicycling is an affordable form of transportation. When safe facilities are provided for bicyclists, more people are able to be productive, active members of society. In comparison, car ownership is expensive, and consumes a major portion of many Americans income. The cost of operating a car for one year is approximately $5,170 (AAA Mid- Atlantic) The cost of operating a bicycle for a year is only $10 (League of American Bicyclists). Transportation benefits: Many of the trips that Americans make every day are short enough to be accomplished on a bicycle. In 1995, the National Personal Transportation Survey (NPTS) found that about 40% of all trips are less than miles in length which translates to approximately a 10 minutes bike ride. In fact, a 1995 Rodale Press survey found that 40% of adults in America would commute by bike if safer facilities were available. Health benefits: With regular cycling you will be less likely to suffer from coronary heart disease, high blood pressure and other illnesses 3. Cycling can also help you control your weight, keep you firm and help you feel great about yourself. The British Medical Association states that cycling only 30 minutes per day adds significantly to your life expectancy. Environmental benefits: Motor vehicles create a substantial amount of air pollution. Transportation is responsible for about 80 percent of carbon monoxide and 50 percent of nitrogen oxide emissions in the U.S. In contrast, cycling produces no pollution at all so you ll actually be helping to reduce air pollution and improve your environment by switching from motor vehicles to cycling. Quality of life benefits: Better conditions for bicycling and walking have intangible benefits to the quality of life in cities and towns. Where people can regularly be seen out bicycling and walking, there is a palpable sense that these are safe and friendly places to live and visit. The negative impact: A majority of bicycle thefts are in fact opportunistic ones 4. With a more robust bicycle theft prevention and recovery system in place, opportunistic thieves will not only find themselves with fewer opportunities, but will also run the risk of being tracked down easily. Considering all this data, the need for a more robust bicycle theft prevention and recovery system appears to be great. Our survey results support this argument by showing that 50% of the bicycle owners are not satisfied with their current locking systems. In summary, there is a large market opportunity for an improved product for bicycle theft prevention. Existing locking systems are not sufficient for preventing theft and there is a great need for a better 5

6 theft prevention system in terms of strength, reliability and ease of use. Such a system would have a very positive net effect on the local communities, and the nation at large. Previous Designs Bike stores carry several different types of locks to protect bicycles from theft. Below are the basic common four types that can be easily found in an ordinary shop. First of all, there are U-Locks which are basically made of rigid metal bars in the shape of the letter U attaching to a crossbar section. The most popular brand of U-Lock is the Kryptonite Lock. The U-type locks are generally the most trusted type of lock since they are very strong. However, they have some major deficiencies. First of all, there was a defect with one of the types produced which made it possible to easily open a lock with an ordinary pen as shown in the video. ( Secondly, the material used can be broken very easily when it freezes. So, a U-Lock can be easily broken if the criminal has Freon. The second type of lock found in an ordinary bike shop is the chain type. It is basically a chain that you can lock with either a key or a combination lock. If they re thin, they can easily be cut with simple wire cutters. The most popular brands are St. Pierre and Kryptonite and they are made of hard metals preventing the thieves from getting a grip on them with a cutting tool. They come either with small U-locks or bolt-type locks. Even though they have the advantage of securing the wheels as well; they have some disadvantages. The fact that they cannot be mounted on bikes, their high costs and heavy weights can be listed as disadvantages. Since they cannot be mounted on bikes, the users should carry them in their backpacks, which increase the time to lock. Cable locks are similar to the chain locks but they re lighter and weaker. Most of them can easily be cut with bolt cutters. They re usually used as an external protection for the bike parts such as the wheels and the seat in combination with a U-Lock. 6 The O-Locks are being used to secure the wheels. Only a few manufacturers are producing them such as Bike Club and Masterlock. They re mostly used in Netherlands, China and Scandinavia. They re mounted on the bike and they block the wheels preventing their motion. They do not secure the whole bike; they just prevent riding it and secure the wheels. 5 As seen from the statistics included in our introduction section, these common locks are not really successful in theft-prevention and this is a well-known problem. The attempts to solve this problem included either designing a brand new locking system or improving the existing locks by adding features. One of the commercial products found in the market is an integrated alarm system. It s produced by CyberNexus and being sold under the name of Ducharme in Europe. The alarm goes on whenever the bicycle is moved and it has a false trigger alarm. The price is around $35. 7 ( ) Another alarm system that s available is one that is integrated with a cable or chain lock. The alarm goes on whenever someone attempts to cut through the cable. 8 There are several manufacturers producing these alarm-integrated cables and their prices are around $0. Even though alarms are definitely a way to deter some thieves, they are insufficient in deterring professional thieves since they are the ones who can easily deactivate alarms that are mounted externally. Another important point to recognize at this point is the fact that people usually 6

7 ignore alarms and even thefts when they see them. ( ) Since bike-theft is a common problem, a lot of designers had different ideas to attack the problem resulting in a huge database of patents that are available in US Patents and Trademark Office. The most appropriate ones are listed here. Since several categories are of interest, below patents are grouped together by their relevance to defined categories. The first category is designing a better lock in terms of its strength and mechanism. A simple sketch of the US Patent 6,668,605 is seen on the left. This is simply a lock that extends from the pedal crankshaft. It is attached by screws and the drilling arranged in the middle of the pedal crankshaft. The cable or chain part is similar to the known locks and it secures both wheels as well as the frame. The US Patent 6,751,99 introduces a lock which will be attached to a bicycle frame member. It has two arms that can swing and extend from the mounted unit. One of these two arms secures the frame and the other one secures the front wheel which can be seen clearly on the picture. This is a sketch for the US Patent 5,889,463. It is an anti-theft device which is easily understood as a concept by just looking at the picture. A second category would be the locks that aim to secure the bike parts (i.e. wheels and seat) as well. 7

8 US Patent 6,948,878 is a locking quick release device that can be used for two different purposes. One, it can be used as a device for allowing quick and easy release and adjustments to the seat and the wheels. This is important since reducing the time it takes to lock is crucial. Secondly, it can be used to lock these parts to the frame to deter theft. The US Patent 6,37,376 is a Bicycle Steering Lock as seen in the picture. There is also a sprocket lock available as US Patent 5,730,01. Another area which will help us to reduce the time it takes to lock/unlock is to look at the remote lock systems that can be implemented on bicycles. US Patent 6,759,88 Remote lock operation apparatus for light vehicle uses infrared receiver to implement the remote lock system on the bar handle is an example in this category which will help us. A third category can be various kinds of integrated alarm systems as mentioned before. 8

9 The US Patent 6,191,685 is an example, which is a Bicycle theft protection system with laud alarm connected to or mounted in the bicycle. There is a Bicycle cover with an attachable alarm system (6,040,764) that can be seen in the picture. Even though this kind of thing will definitely increase the locking and unlocking time which is undesired in our case. The fourth category would be tracking systems that aim to locate the bikes if they get stolen. Such a feature will enable the owner to get his/her bicycle back in case of theft. The survey results show that the market for this system is limited. A helpful product would be the US Patent 5,955,965, which is a bicycle having a locating system attached. The locating system in this product basically responds to call signals from the call station by transmitting locator signals allowing quick and easy tracking recovery of missing and stolen bicycles. Another market that has very similar products is the market of locks for motorcycles. Since the motorcycles are much expensive than bicycles, the chain locks available for them are much more secure. Their increased level of security is a result of strength which results from the materials used. They might have the disadvantage of heavy weight, but it is definitely a market that should be considered while designing a new bicycle lock. As seen from the above patents; a great range of products have been designed to solve the problem of bicycle theft. However the commercial products available in the market today are insufficient in meeting the consumer needs and preventing theft. It is obvious that there is a need for a lock which will secure the whole bike, which is lightweight with an increased level of security. Even though there are a variety of patents, there is no single design which integrates different capabilities a strong yet lightweight anti-theft system for the whole bike 9

10 with additional features such as integrated alarm and tracking systems. The attempt is to come up with a single product design which will integrate all these categories in this project. Design Objectives and Proposed Solution Mission Statement To design an anti-theft system that effectively and appealingly secure bicycles against theft. Key Design Objectives The successful design must meet the following objectives. The product should be kept mounted to the bicycle both when being used and when the bicycle is being ridden. The locking process should be quick and easy. In addition, it should have the following basic characteristics: The product should increase the difficulty of successfully stealing a bicycle. The product should withstand normal use and some amount of abuse. The product should be retrofittable to the majority of common bicycle frames. The product should not interfere with normal operation of the bicycle. The product should be able to survive exposure to harsh weather without significant or noticeable degradation. The product should use very little power, if any. The product should be lightweight and compact sized. The product must be unlocked by its key 100% of the time. The product should be aesthetically pleasing. Proposed Solution One of the key problems to be solved is the inconvenience associated with the current strong locks. They are heavy, bulky, and need to be carried by the bicyclist. They can get buried in a backpack, or even forgotten. Therefore, the proposed solution must address this issue in particular, as indicated in the design objectives. At the first stage a system idea was proposed to solve the problem effectively and meet the design objectives. This system consists of several subsystems as listed below. A mechanism for conveniently carrying the lock secured to the bicycle. A strong lock which eliminates the problems associated with current locks (i.e. harder to cut and eliminates the problems associated with U-Locks). A method of easily locking individual parts. An option for a keyless remote system An option for a bicycle tracking system 10

11 Preliminary Market Research With our problem statement in mind, we distributed a customer survey in order to identify the market needs, average concern level and specific features which consumers will find attractive in a locking system. Our preliminary survey results (see Appendix B), with 9 respondents, have shown the following information to supplement the national statistical data. Majority of the respondents own an expensive bicycle (costing over $50) 5% of those responding have had their bicycles stolen at least once 13 respondents would be willing to pay $5 to $50 for a fool-proof bicycle lock; would be willing to pay more than $50 This data is crucial in determining the target market and corresponding needs. The fact that a majority of people own expensive bicycles is important, since these people will usually be more concerned and will be willing to pay more for a stronger lock. As a result, the target market is determined to be the consumers who own relatively expensive bicycles with a higher concern level and willing to pay more for a strong lock. Identification of Features to Include in Device The most important role of the survey was to identify the features of greatest interest to the customers so that the proposed solution could be evaluated and harmonized with those results. The results showed that the respondents are not currently interested in tracking systems or keyless remote systems. Tracking system: The interest in this system was very low, with an average rating of.9/7. The distribution of responses to the tracking system is given in Figure 4. Furthermore, consumers are not willing to pay enough to cover the cost of implementing such a system. Therefore, this system will not be included at this time. Electronic key: The interest level in the electronic key option was very low, with an average rating of.5/7. (See Figure 5 for distribution of responses.) Therefore, this option will not be included in the first-generation system design. The majority of respondents currently use cable or chain locks (17/9). Only 4 people are using U-Locks, which is surprising since it is known to be the most popular strong lock in the market. This indicates that a solution including a cable or chain would be acceptable to the market. Respondents show more concern with the theft of bicycle wheels than of the seat. A total of 16 people lock their wheels along with their frames, while only one person reports locking the seat separately. 11

12 Interest Levels for Tracking System 8 6 Number of People Interest Level (1- Not interested at all & 7 - Very Interested) 0 Figure 4 Interest Levels for Electronic Key 1 Number of People Interest Level (1- Not interested at all & 7 - Very Interested) Figure 5 Therefore, our proposed solution was modified to concentrate on a strong lock, ease of transportation/storage and use, and an option to secure bicycle parts. The electronic key and tracking system features are eliminated at this point due to lack of interest. 1

13 Conceptual Design Concept Generation As discussed in the previous section, the characteristics of the final design were determined according to the consumer survey results. The concepts generated concentrate on strong locks, a system which is easier to use especially by eliminating the need to carry during riding, and aesthetics and customer appeal. Details are discussed in the following sections. Concept A A housing is mounted to the bicycle. This housing supports two major components. One is a locking mechanism, similar in style to a MasterLock construction grade padlock. The exposed area of the shackle is to be as small as practical, in order to increase the difficulty of cutting it. The other component is to be a spindle with a flexible component wrapped around it. This is to be spring-loaded, in order to retract when not in use. The user would pull the cable or chain out, wrap it around the bicycle rack, and lock it to the housing. This would satisfy the following key design objectives: The product would be permanently mounted to the bicycle. The locking process is quick and easy. While riding the bicycle, all components are safely out of the way. In addition, this concept has the following characteristics: The lock itself would be difficult to break. If a sufficiently strong flexible component (cable or chain) were used, it would be difficult to steal the bicycle. While it is not expected that the product would be dropped often, a suitably strong housing would survive impact with the ground and protect the spindle mechanism. The product could be used on a wide variety of different bicycle frames, though a suitable adaptor sleeve may be required for some. One possible embodiment of this concept is shown below: Figure 6: Design concept A 13

14 Concept B Concept B is somewhat similar to Concept A. However, instead of a spindle to retract the flexible component, clips are provided for securing it to the bicycle frame. The housing mounted to the bicycle is retained, as is the style of lock used. This concept has many of the same advantages of Concept A. In addition, it has the advantage of having fewer parts that could fail, due to the elimination of the spindle. Its disadvantage, however, is that the elimination of the retracting feature adds an extra step for the user of the product. He or she must clip the flexible component before riding. Figure 7: Design concept B Concept C Concept C involves a housing mounted to the bicycle frame, with a rigid part used to lock the bicycle to the bicycle rack. This rigid piece would be similar in shape to a Kryptonite U-bolt lock, and would mount to a pivot on the housing. This would allow the lock to be pulled out for use and snapped back into place in order to not interfere with normal use of the bicycle. This has many of the same advantages of Concepts A and B. One difference is that, by eliminating the flexible part, it restricts the way that the bicycle can be locked. While bicycle racks are somewhat standard, there are some variations, and some people find it necessary to lock their bicycle to some object other than a standard bicycle rack. The advantage of this design would be that the use of a rigid lock would allow for a thicker, stronger product that is less likely to be broken or cut. 14

15 Figure 8: Design concept C Initial Design Evaluation & Selection Based on the advantages and disadvantages, as enumerated in the preceding section, the concept of choice is Concept A. The detailed comparison of concepts, with the various criteria weighted and evaluated, is shown on the Pugh Chart. These criteria and their weights were chosen based on fundamental requirements for a successful lock, as well as the characteristics identified from the market study. The base case is chosen as the Kryptonite high security chain lock. It is a 3`11`` and 6.1 lbs chain integrated with a small U-lock at a price of $80. This lock is Kryptonite s maximum security lock for urban areas, college campuses and other areas with a high risk of theft. It is most appropriate as the base case since it aims to maximize the security level and it is a chain-type lock. Concept A, as indicated, can be expected to satisfy the design objectives. 15

16 Weight Sketches Base Design Design #1 Design # Design #3 Design Criteria Base Concept Concept A Concept B Concept C Reasonably priced Mounted to the bicycle Increase the difficulty of stealing a bicycle 7 Withstand normal use and expected abuse 9 Retrofittable to common bicycle frames 10 Does not interfere with bicycle riding 8 Withstand exposure to Michigan weather 6 Uses little power Quick and easy locking Lightweight Reliable unlocking process 9 Compact size Aesthetically pleasing Total Points

17 α Prototype An initial prototype was made of this concept in order to verify that a design of this sort can be mounted on a bicycle without interfering with normal operation. This prototype is shown below. Figure 9: Alpha prototype Figure 10: Alpha Prototype This prototype revealed several important things. First of all, it indicated that the spindle needs to have some form of spiral groove or other means of guiding the flexible member (represented here by the clothesline) in order to wrap it properly when retracted. Second, it pointed out the need to carefully address the question of size. While the spindle must be of a sufficient height to fully wrap the cable, it is also necessary to restrict the height in order to mount in the available space. Furthermore, examination of the bicycle reveals that many convenient mounting locations have cables and/or wiring running along them. The housing will need to be designed to avoid causing damage or interfering with these components. 17

18 Engineering Analysis Prior to formulating an engineering optimization problem, certain design characteristics must be formulated. Among these are the basic configuration of various parts and the choice of materials to be used for various parts. For the bottle, a polymer of some sort is an obvious choice. Many drink bottles are made of polymers, and they are lightweight, comfortable to hold, come in a variety of colors, and resist breaking. One good choice would be LDPE (low density polyethylene); it can be colored to serve aesthetic needs, and has tensile strength (1000 psi) and elastic modulus (30 ksi) sufficient for the application. The spindle is a part that requires strength and stiffness. It will be subjected to loads from the spring and from the cable, and must withstand them over continued use. For that reason, steel is chosen for this part. A variety of steels are available with different properties and costs; for this part we will choose 100 steel. The material for the housing must satisfy a number of different requirements. First of all, it should be lightweight (i.e., lower density). Second, it needs to have sufficient strength to withstand normal use and abuse of the product. Third, as it is clearly visible to the consumer, it needs to have an attractive appearance. As discussed in the section on economic analysis, there is often a tradeoff between lower cost and lower weight, and that does hold for many materials. However, as shown in Figure 11, there are some materials with a relatively low price per unit volume which also feature a low density. One of these materials is aluminum; another is GFRP (Glass Fiber Reinforced Polymer). For this part, we will choose GFRP as the material. Cost-Weight Material Data $160, $140, Price/Volume ($/m 3 ) $10, $100, $80, $60, $40, $0, $0.00 CFRP GFRP Al alloy Ti alloy Density (Mg/m 3 ) 4140 steel 100 steel Figure

19 Our optimization is designed to find values of the design variables, subject to various constraints, that will result in the lowest weight of product. The design variables are the overall bottle height, H, spindle height, h, spindle diameter, d, the diameter of the bottle top, D, the cable diameter, a, and the length of the cable, L. In order to perform this optimization, certain relationships need to be developed for use as constraints. First, all physical quantities need to be greater than zero, since negative dimensions do not make physical sense. Furthermore, we wish to select a bottle height that is greater than the spindle, and the bottle top s diameter is to be larger than its bottom. Its bottom is sized to fit inside the spindle. These choices yield the four constraints given below: h f 0 d f 0. 5 H! h D " d! 0. 5 The volume of the bottle is a function of its physical dimensions. We have made a design decision that the bottle s volume should be at least 500 ml in order to be an attractive feature to the user. This choice allows the development of an additional constraint, as shown below. ( h) Volume of the bottle D ( H! h) + ( d! 0.5) = " 4 500ml = 30.5in 3 Weight of the bottle: D ( H " h) + ( d " 0.5) h! The weight of the bottle can be determined based on the design variables, the thickness of the material, and the density of the material. The parameters of thickness and density are explicitly shown in the equation because there is a possibility of changing them as the design progresses. &( # W = pt$ D + ( D( H ' h) + ( d ' 0.5) h! % 4 " Relations between Cable Length, Spindle Diameter, Spindle Height & Cable Diameter The cable length, spindle diameter, spindle height, and cable diameter are interdependent, due to the requirement that the cable must wrap around the spindle. The equations below relate these quantities and will be used in the optimization. Note that the data points used for the relation between a and d were the result of data from McMaster-Carr. n = number of turns h = na! n = h a! dh L = n! d = a If we assume a linear relation between d & a 19

20 5 a =, 16 3 d = a =, d = 3 8 d! 3 = 4( a! 0.65) d! 3 = 4a!.5 d = 4 a Cable weight W lb =! a L(0.83 ) = 0.a L 3 4 in Weight of Spindle Weight of housing '!! W = 0.073&!! % ( d! ( d! 0.5) )( h! 0.5) d ( 0.5) ' ( $ % " ( ) & 4 # ( 0.5d + ( d! 0.5)(! 0.5 ) W = W = 0. h -3 d + 1 +, ( 0.5) ( d ) ( d 4 0.5) 4 ( 1.5) , 0. / *. ( / () /, 3 d d d 0 5! ( 0.5) ( d ) h ( d )!. / 5 3 d / * ( + (). + / $!! # * ( )" W { d (0.893) + d( 3.963) h[ ] } = d Total Weight The total weight is the sum of the various components, and therefore the optimization problem is as stated below. Note that certain things, such as particular material choices, are implicit in this formulation. Any changes made to the design, beyond the values of the design variables, will result in a slightly different formulation. Proportionality of dimensions: In order to maintain a pleasing appearance, certain proportionalities are analyzed. These relations are discussed in the section on product aesthetics. 0

21 Minimizing: Subject to: '( W = pt % D + ( D ( & D ( H! h) + ( d! 0.5) $ h " + 0.a L # { 1.663d ( 0.5d + ( d! 0.5)( h! 0.5 ) d (0.893) + d( 3.963) h[ ( H " h) + ( d " 0.5) h! h f 0 d f 0.5 H! h D " d! 0.5 dh "! 30 a 5 a! 16 5 a! 8 d! 4 a h! 6 d! t = Thickness of the bottle p = Density of bottle material Results of this optimization are as follows: Design Variables D (bottle dia.).99 in. H (bottle height) 8.83 in. h (spindle height) 6.00 in. d (spindle dia.).00 in. a (cable dia.) in. L (cable length) in. 1

22 β Prototype Figure 1. Figure 13. Two views of the beta prototype are shown above, one as assembled and one section view. For aesthetic reasons, the spindle is concealed within the housing. The spindle is hollow, with a bottle fitting into it as an added user feature. The cable passes through the housing on the far side, as shown here, with the lock on the near side. The cable is pulled out, passed through the bike rack and the bike s frame and/or wheels, and then locked. The cable used is a construction-grade plastic-coated cable from MasterLock, pre-coiled with a loop at the end for locking. It was chosen for strength and flexibility. The lock is MasterLock s construction grade padlock, a keyed lock that is easily locked and unlocked. It is operated simply by turning the key, with no need to align the shackle in order to operate the lock. This mechanism would be amenable to the future addition of a keyless remote locking/unlocking feature, if it should become economically viable. The cable is retracted onto the spindle by means of a constant-force spring. The spindle is to be made of 100 steel, and the housing from GFRP, as discussed previously. For the beta prototype, these parts were made on the rapid prototyping machine. This manufacturing method is chosen for the prototype due to the ability to easily produce the desired geometry.

23 We expect this design to meet all of the design requirements, as discussed previously. The actual prototype, as well as a prototype of the housing made from welded sheet metal, is shown below. Figure 14. Other Options & Future Enhancements It would be possible to implement the concept chosen as described above with an additional feature. This feature would be a mechanism to lock the bicycle wheels to the frame, in order to prevent component theft. These locks would be similar in style to pneumatic bicycle brakes, but would have longer lever arms in order to go through the bicycle wheels. These locks could be locked separately, or could be linked to the main lock via pneumatic cables. The major advantage of this is that it would decrease the possibility of component theft. By locking the wheels to the frame, a potential thief would be less able to steal the wheels of the bicycle. Naturally, adding additional components will increase the cost, and may require more time from the user. As indicated, these locks could be linked via pneumatic cables to the main lock. This would lead to the question of what happens when pneumatic cables are broken or cut. Theft prevention would dictate that failure of cables should result in the locks being on. However, safety concerns would dictate the opposite. Other options were discussed which could also be implemented in conjunction with any of the above. One of these options is to supply a keyless remote, similar to the key used for locking and unlocking cars. This key would allow the user to release the bicycle lock(s) by pressing a button. While this would be a convenient feature that may be desirable to some, it would increase the cost of the system, and therefore should not be a standard part of the system. The survey results demonstrate very low levels of interest in such a keyless remote system. However, this feature may be more feasible in the future, particularly if consumers gravitate towards the option of component locks. Another option is the inclusion of a tracking feature, utilizing either RFI or GPS technology. This option would allow the user to learn where his or her bicycle is located at a given time. While this could be useful in the event of theft, there are several arguments against it. Aside from concerns over privacy being tracked by others the cost of the locking system would 3

24 increase, and the system could be easily defeated. GPS signals could be blocked by many buildings, and RFI transponders can be blocked with aluminum foil. Furthermore, the survey results show that there is almost no interest in such a tracking system. All these arguments lead to the elimination of such an additional feature at this time. This option may become economically attractive in the future due to new technology and changes in the marketplace. Ergonomic Analysis Ergonomic considerations are important in any product that is used by humans. In this case, there were two main ergonomic considerations. The first was that the product should not interfere with normal use of a bicycle. If the user were continually scraping his or her legs against the product, or if it were to affect the normal pedaling action, it would not be a good product. This consideration was the ultimate source of the limitation on the spindle diameter that appeared in the engineering optimization. Further, the product must not shift the center of gravity of the bicycle significantly. This was a major reason why we chose to optimize for weight, with the goal of decreasing the weight of the product. Also, the product should not require excessive force to pull the cable out for use. It can be expected that a bicycle rider will be in reasonably good health and will be able to exert a moderate force. It is expected that this force will be approximately 3 pounds. 9 This is a primary factor in the spring selection for the spindle. Aesthetic Design Designing for aesthetic appeal is especially important in today s world. More so important for us because we intend to target high-end consumers who are more conscious about the look of a product. To appeal to our consumers, we have incorporated the Golden Ratio into our design as much as possible. The golden ratio is the following algebraic irrational number with its numerical approximation: At least since the Renaissance, many artists and architects have proportioned their works to approximate this ratio, believing this proportion to be aesthetically pleasing. We have also applied this ratio, to a crude approximation, in our design as well. For example, the ratio of the overall length/width is 1.3, the ratio of the height/length is All of these dimensions can be seen in the Appendix. For future development purposes, we are interested in converging these ratio s to 1.618, the golden ratio. Colors and color combinations also play a key role in aesthetics. We determined that our target consumers would be most interested in a design and color scheme that would look safe and trendy. Also, we determined the texture of our product to be smooth, metallic and hard. The idea was to apply Kansei engineering principles to help us determine the best characteristics for maximum aesthetic appeal. However due to time limitations we took an extremely rudimentary version of these principles, and used basic surveying techniques to 4

25 determine the best color combination: Purple with silver stripes. For future purposes, we would like to incorporate the full principles of Kansei engineering. 5

26 Economic Analysis In addition to engineering optimization, a microeconomic analysis was conducted. A separate microeconomic analysis is necessary to ensure that the financial objectives are being met along with the engineering objectives. This was done by using the equation shown below, and maximizing for profit, π, which is a function of total revenue earned, R, the price per product, P, the total cost for producing and shipping to the customer, C, and the quantity of products sold, q. " = pq! C Product Demand A linear demand curve has been estimated and can be seen in Fig. 15 below. This was determined by using our 9 survey results and extrapolating it to represent our market size of 00,000. Demand vs Price Quantity Demanded y = -361.x Product Price, p [$] Figure 15 6

27 The demand curve function is shown in the equation below, where λ p is the price sensitivity, and θ is the demand quantity if the product was sold for free (y-intercept). From Fig 15 Q = " #! p P Q = 00000! (361) P These results were extrapolated from our survey results. In order to scale it correctly, the market size of 00,000 was accounted for. The market size was estimated by considering the following information: 57 million people rode a bicycles last summer 1. Furthermore, 50% of bicycle owners are not currently satisfied with the safety in the biking communities. Also our survey results show that 50% of bicycle owners have bicycles costing more than $50, which is our market target area. According to these data, we are estimating (57 million * 50% *50%) 14.5 million people have relatively expensive bikes and are not satisfied with their current locks. The target market is estimated to be 1% of these people, resulting in a market size of approximately 00,000. Product Demand with Variable Design Attributes The quantity demanded is affected by design attributes and therefore its sensitivities to product attributes are crucial to our demand model. The attributes considered for our bike theft prevention system are: steel cable length, α l, total weight of the product, α w and overall size of product, α s. Effect of Cable length on Demand. Fig. 16 below shows how sensitive cable length is to the quantity demanded. As the length of the cable is increased, the product demand also increases. Quantity Demanded y = 8718x Length [ft] Figure 16 Using the demand curve function equation on pg. 5, we find the length sensitivity, λ l = 8,718 Effect of Weight on Demand. Fig. 17 shows how sensitive weight is to the quantity demanded. As the weight of the product increases, the product demand decreases. 7

28 50000 Quantity Demanded y = x Weight [lbs] Figure 17. Using the demand curve equation on pg. 5, we find the weight sensitivity, λ w = -19,660 Effect of size on Demand. Fig. 18 below shows how sensitive product size is to the quantity demanded. As the size is increased, the product demand decreases Quantity Demanded y = x Width and Depth, [in] Figure 18 Using the demand curve equation on pg. 5, we find the size sensitivity, λ s = -79,316 8

29 Revenue Equation The revenue can be expressed in terms of product characteristics and price. Revenue = Price x Quantity R = R = R = p % q p % ( ' # & " p p + "! $!) p % (# & " p + " % $! + " % $! p l l w w + " % $! ) s s Product Cost The total cost for production in the first year is projected to be $5 million. This was determined using the equation below, where C F represents the Fixed annual cost and initial investment cost, and C V represents the Quantity dependant Variable cost. C = C F + qc V Following calculations assume that the quantity produced equal to the quantity sold. Our calculations are made over one year. Fixed Costs Total Fixed cost for the first year is determined to be $1.5 million. This is a function of the initial investment startup cost and the annual fixed costs. The table on page 30 shows the breakdown of these costs 9

30 Initial Investment Cost Annual [$] Product Development and Design Legal fees Annual Fixed Costs $60,000 engineering salary 3 hired engineers Developing 30 prototype models Trade Show Software licensing, Tooling and assembly, etc. Registering company as an LLC Setting up Patent $500,000 $0,000 Assembly & Warehouse (Rent) $1,500 monthly $0,000 Inventory Control Overhead Advertising $0 hourly Labor Rate 1 stockroom person $40,000 $400 monthly - utilities $500 monthly - insurance $11,000 $50,000 a year on internet $150,000 on bike magazines $70,000 annual salary for 3 salespersons $610,000 ` Total Fixed Cost Total Conservative Fixed Cost (1.5%) $1,00,000 $1.5 million Product Development and Design. A total of $500,000 is estimated for our product development and design. We expect to develop several more prototypes and then manufacture up to 30 individual parts and perform various engineering tests. This process will be head by 3 engineers working at a modest salary of $60,000 annually. We also expect to launch our product at a trade show, costing us approximately $10,000. The remainder of the $500,000 is expected to be used for other items such as tooling and assembling, software licensing, etc. Legal Fees. A lawyer will be hired to legally setup our company as a Limited Liability Corporation (LLC), costing us approximately $9,000. To patent our product, $11,000 will be set aside to patent our. Assembly & Warehousing. A storage area for maintaining inventory of the manufactured locks will be needed for the products to be readied for shipment. The estimated cost for the warehouse is $0,000 for the first year, based on a $1,500 monthly rental cost. Inventory Control. A stockroom person would be hired to manage the inventory at an hourly rate of $0/hr. Overhead. The overhead includes both utilities and insurance, costing $400 and $500 monthly for the first year. This totals to an annual overhead fee of $11,000 30

31 Advertising. Three different channels will be used to advertise our product, costing a total of $550,000 for the first year. Internet: Up to 15 popular websites will be targeted for internet advertising. Since one click on our ad costs $0.50, a total of $50,000 will be spent on this advertising mechanism, assuming we receive 100 clicks per day. Magazines: 5 different biking magazines will be targeted. Considering that a typical page ad for a monthly edition magazine costs $,500, a total of $150,000 will be spent on this advertising strategy. Sales Representatives: 3 professional salespeople will be hired to market our product specifically amongst bicycle shops, bicycle groups, campus areas and bike rentals shops. Each Rep will be paid $70,000 annually including benefits. This is a total of $10,000 Research & Development. Once the Product Design and Development stage is complete, the engineers will focus their attention on R&D. The cost for this is accounted in the aforementioned stage. Variable Costs The variable cost for each product is estimated to be $ The breakdown of the variable cost structure is shown below in the table. Variable Cost Cost per product Outsourcing Manufacturing $5.00 Purchasing internal component parts $8.00 Padlock $.00 Cable $10.00 Labor costs for Packaging & Assembly Assuming it takes 5 minutes to assemble and package each product $.00 Distribution Based on costs from UPS $6.00 Warranty Assuming 1% of all products sold will be returned on warranty $0.70 ` Total Variable Cost Total Conservative Variable Cost (1.5) $44.00 $55.00 Outsourcing manufacturing. The assumed manufacturing cost for a single product is $0, assuming farming out. Purchased internal components. One padlock and a cable will be purchased for each product. These costs will be around $10 total. Labor costs for Packaging & Assembly. It takes 5 minutes to assemble a single product. Assuming $5 per hour wage, the labor cost per product is $0.16. Distribution. Our products will be shipped using UPS, through their Business Solution shipping scheme. Based on weight and quantity, the shipping cost for each product will cost approximately $

32 Warranty. Assuming one out of every 100 products will be returned and a $70 price; the warranty will add $0.7 for each product. Attribute Variable Costs The three attributes chosen are cable length, product size and product weight, and each has an associated variable cost. Cable length. As we increase the cable length the cost for a single product will also go higher. This will increase the overall variable cost. The cable prices available are $/foot and $4/foot, average price being $3/foot. Weight. The weight of our product depends on the density of the materials we are using. λ w was calculated assuming a linear relationship between weight and price. Two points were determined by using the values for steel and aluminum. The results show that each pound has a $0.19 effect on cost. Optimization Problem: Maximize Profit The profit equation that should be maximized is: ( p! q) "( C )" ( C q) # = R " C = p! q " C = var fixed iable! [( p! CVariable )# ('! & p p + & l # "% l + & w # "% w + & s # "% s ]! C fixed $ = ) [ C # "! ] $ [ C # " ] C! Variable = C V $ general + V $ length l V $ weight q = # & " + " % $! + " % $! + " % $! ) ( p p l l w w s s Baseline values for the product attributes we set are determined in the engineering design section at "!. ft and! w = 10lbs and " s! 5inches l 5 The optimization problem is solved with the constraints on price and change in attribute values (!! ) making sure that resulting length, weight, size and price values are positive. The last contraint resulted from relating the engineering variables with the attributes. The relation between the cable length and total size is used as a constraint in this optimization problem. The equation relating! l and! s is: w 3

33 " # d # h L $ a % L " # h = % d a " # 6! l $! s # 5 8! s! l = 48# " # 5 Excel Solver was used to solve the optimization problem with the given constraints as included in Appendix D. The maximum profit is! = $ 5,180,309 at the production level Q = 1,735 at a price $ The cable length is 5 feet, the weight is 5lbs and the size is 5.08 inches. The weight and the cable length were assumed to be independent at this point; however this is not a reasonable assumption since a 5 feet cable at 5lbs of weight is not achievable. These variables are related in the later optimization based upon the second survey. 33

34 Marketing Analysis Market Size The market size was estimated by considering the following information: 57 million people rode a bicycles last summer 1. Furthermore, 50% of bicycle owners are not currently satisfied with the safety in the biking communities. Also our survey results show that 50% of bicycle owners have bicycles costing more than $50, which is our market target area. According to these data, we are estimating (57 million * 50% *50%) 14.5 million people have relatively expensive bikes and are not satisfied with their current locks. The target market is estimated to be 1% of these people, resulting in a market size of approximately 00,000. In the second year, the market size is estimated to be % of these people and 3% for the third year. For the fourth and fifth years, the market size is assumed to stay constant 3% percent of 14.5 million people. Functional Relationship & Logit Model The previous profit models estimated elasticity values for the engineering functions and price. A survey of potential buyers was conducted for a better understanding of these elasticity values, these were then used to run another optimization to maximize the profit based on a redesigned locking system. The survey was administered online for a week and respondents were part of the fall 006 APD class at the University of Michigan. The survey took approximately 15 minutes to complete. The survey gave participants the option of choosing one of three locks or a no choice option. The results produce estimates of beta values, or sensitivities to changes, with respect to product characteristics using a conjoint modeling process. The attributes chosen to represent our design were: price, weight, and cable length. A linear demand curve is expected for price and weight. As the price or the weight values increase, the demand will decrease. The increase in demand will continues up to a certain length value and after that, the demand should start decreasing since people would not want cables that are much longer than necessary. The levels chosen for the product characteristics are shown in Table ##. Characteristic Level 1 Level Level 3 Level 4 Level 5 Price $30 $60 $90 $10 $150 Length feet 3 feet 4 feet 5 feet 6 feet Weight 5 lbs 7.5 lbs 10 lbs 1.5 lbs 15 lbs Product characteristics and their levels for the discrete choice analysis. The graphs of the three independent beta values resulted from the survey are given in the figures on page 34 and 35. These beta values represent the customers sensitivity to each of the product attributes relative to one another. The bigger beta value, the bigger the sensitivity is. For example, customers are most sensitive to changes in the price and are least sensitive to weight changes. This data can be used to justify additional engineering work in making sure 34

35 that the larger effort to reduce the price or to justify choices not to spend much effort to adjust the cable length, because it will not impact the market in a significant way. The beta values for the price turned out to be linear as expected. The weight and length are linear within a certain range; the values settle down out of these ranges. This represents the fact that, weight or length changes does not really matter to people when they re above or below certain values. Our no-choice has a positive value, which means that the customers are making value out of not getting our product. This is reasonable for our product, since its target market is the consumers who own expensive bikes and our first survey results showed that only a quarter of the class members own a bike which is worth more than $50. Price Beta Values Price ($) Cable Length Beta Values Cable Length (ft) 35

36 Weight Beta values Weight (lbs) Product characteristic levels and corresponding beta values Demand Function Our microeconomic model estimated a profit of $5 million at a price of $10. The resulting product has a cable length of 5 feet and a weight of 5lbs since no relationship was taken into account between the cable length and the weight. In our market analysis, continuous functions of choice probabilities with respect to price and design characteristics were obtained using Excel s spline add-in function and Excel solver. The profit was maximized at $ $48,195 for the first year using the cost function with the following additional constraints to limit the solution from extrapolating beyond the product characteristic levels of the survey: $30 < Price < $150 feet < Cable Length < 6 feet 5 lbs < Weight < 15 lbs Weight = 3 + *Cable Length The maximum profit occurs with a 5% market share, corresponding to 49,915 locks sold. The price level at this optimum point is $91.8 and the resulting product has a 3feet cable length and 9lbs weight. 36

37 Linearization of the Marketing Demand Model In the resulting design from the market analysis demand model we have the following values for the attributes: Price = $9 Weight = 9 lbs Cable Length = 3 feet At these values, the lambda values are calculated using the linearization method in excel: λ w = λ l = 851 λ p = -157 These absolute values for each of these lambdas are higher in our microeconomic analysis. So the change in each attribute affects the result more than we expected. The estimated is lower as well in our marketing model and it makes more sense. Breakeven Analysis As indicated before, the market size continues to grow and double each year for the first three years. Then it settles down. The breakeven analysis is conducted under these assumptions. First of all the present value for the profits of each year is calculated. Assuming a 8% interest rate, the net present value turns out to be $37,346,795 if we include a 5-year analysis. In the second year, the market size is estimated to be % of these people and 3% for the third year. For the fourth and fifth years, the market size is assumed to stay constant 3% percent of 14.5 million people. The total number of products that will be sold by the end of the fifth year is This result shows that 5% of the bike owners who have expensive bikes will own our product, which is a realistic number. Market Size Year 1 Year Year 3 Year 4 Year 5 Total Consumers 00, , , , ,000 Our customers (Qm) 49,915 99, , , ,660 Profitability = Revenue - Costs Revenue $4,583,397 $9,166,794 $18,333,588 $18,333,588 $18,333,588 Costs $4,101,0 $3,738,70 $3,738,70 $3,738,70 $3,738,70 Profit $48,195 $5,48,09 $14,594,887 $14,594,887 $14,594,887 $446,477 $4,653,714 $11,585,891 $10,77,677 $9,933,035 Net Present Value $37,346,795 The breakeven analysis shows that LockShot will have quick returns. The tables above show that it does have a profit within the first year. So a detailed breakeven analysis was conducted for the first year. The breakeven point is estimated to be 6 months. 37

38 Startup Cost $36,500 Monthly Profit $70,391 Breakeven Point 6 months NPV Profit First Month $70,391 -$9,109 Second Month $69,941 -$,167 Third Month $69,494 -$15,673 Fourth Month $69,050 -$83,63 Fifth Month $68,608 -$15,015 Sixth Month $68,170 $53,155 Product Design Process Our Design process turned out to be much like what we expected. The major thing that threw us off however was the turnover time for our prototype. At one point we were significantly behind due to issues with the printing lab. Moreover, once we received our part we found some added faults that occurred during the epoxy stage. The design was modified and printed for us again (free of charge this time!), and we were back on track. 38

39 Broader Impact to Society Our product, Lock-Shot, reflects our team and individual values. These values were: Safety, Environment and Aesthetics. The first value is incorporated in the idea behind our product. Lock-Shot has been designed to prevent people from stealing bikes, and this results in the safety of the bike. This also indirectly provides safety for the users; in most cases bicycles are stolen when they are parked in public areas and the users are busy elsewhere. Having their bicycle stolen in such a place forces them to find another means of transportation, exposing them to other risk factors. The second value, environment, has also been incorporated. We can conclude that as more and more bikes users feel safe about parking their bikes in public areas, more and more people will start using bicycles. We have already related in our introduction that one of the major benefits of cycling is the impact it has on environment when compared to other means of transportation. Aesthetics, the third value, has also been incorporated. Efforts were made for our product to exhibit the golden ratio, and surveys were conducted to determine color combinations that would look most trendy. The first two values were accounted for by the intrinsic nature of our product. Our goal for the product is to develop a fool-proof bicycle lock and this in turn has a positive effect on the environment. Aesthetics however, were determined by determining what works best in today s designed world. It was concluded the golden ratio has a universal appeal, and can also be seen on many other grand products such as the VW bug and video ipod. Conclusion LockShot is distinguished by several key features. These are its permanent mounting on the bicycle; ease of use; the retractable cable; and the integrated drink bottle. These features were chosen based on several criteria. A few of the critical ones were to appeal to the target market, to make it more difficult to steal a bicycle, and to distinguish the product from others on the market. One of the key design decisions was what the general configuration of the product should be, and whether to focus more on the convenience aspect or on the strength of the product. Observations of people locking their bicycles seemed to indicate that a product that could be used quickly would be appealing, and that a product that required too much time and effort would not be used, leading to the focus on convenience. The inclusion of the bottle was first suggested by a classmate evaluating the proposal presentation, and was added to the design due to the large number of higher-priced bicycles that are observed to have bottle holders mounted on them. As the design progressed, other key decisions involved the tradeoffs between various characteristics of the product. In general, greater strength required an increase in size and weight. Furthermore, adding length to the cable, which was desirable, conflicted with reducing the weight. This tradeoff was considered in the market study, leading to the design presented here. Detail drawings of this design, and a bill of materials, are presented in Appendix E. 39

40 Further work remains to be done if LockShot were to become a viable product in the market. One vital task would be to conduct a more extensive market survey, specifically seeking out and targeting a large number of people in the target market. This would provide better data on what the design configuration should look like, as well as providing a better assessment of what share of the target market could in fact be captured. Additional prototypes would be useful, both for refinement of the design and for extensive testing. Furthermore, the design could be enhanced with additional features. The first market survey revealed that the interest in component locks, tracking systems, and remote keyless unlocking was limited; however, adding these features as options might find a profitable niche market, particularly as technology advances and makes the electronic features less expensive and more robust. This future work, building on the work described in this report, would result in a truly unique product to serve a definite need for many people. References Woodson, Tillman & Tillman, Human Factors Design Handbook: Second Edition, New York, Mc-Graw Hill Publishing,

41 Appendix A: QFD Matrix Weight Amount of electronics - Power requirements Materials used Physical size Product life + Force to break Weight Time to lock/unlock Time to overcome Technology to overcome Reliability (key opens it, tracking works) Adjustable design Tracking method Easy to implement Inexpensive +/ Durable/rugged +/ Easy to track Protects privacy + + retrofittable + + Easy to use Low maintenance +/ Good appearance Hard to circumvent Protects w hole bike Measurem ent Unit Target Value Im portance Rating Total Norm alized 41

42 Appendix B: First Survey 4

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