A Deceleration Control Method of Automobile for Collision Avoidance based on Driver's Perceptual Risk

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1 A Deceleation Contol Method of Automobile fo Collision Avoidance based on Dive's Peceptual Risk Takahio Wada, Shun ichi Doi, and Shoji Hiaoka Abstact To educe ea-end cash of automobiles, it is impotant to judge necessity of deceleation assistance as ealie as possible and initiate the assistance natually. On the othe hand, we have deived a mathematical model of dive s peceptual isk of poximity in ca following situation and successfully deived dive deceleation model to descibe deceleation pattens and bake initiation timing of expet dive. In this eseach, an automatic baking system fo collision avoidance will be poposed based on the fomulated bake pofile model and bake initiation model of expet dive to ealize smooth, secue bake assistance natually. It will be shown that the poposed contol method can geneate smooth pofile fo vaious conditions. In addition, expeimental esults using a diving simulato will show validity of the poposed system based on subjective evaluation. D I. INTRODUCTION RIVER assistance systems such as waning system and pe-cash safety system have been developed to educe and mitigate cashes in oad taffic. In the view point of peventive safety, deceleation assistance contol is effective when collision isk is high and it is difficult fo the dive to avoid it. On the othe hand, dive can feel anxiety o nuisance against the system if the initiation timing of automatic bake and/o deceleation pofile is not appopiate and it may make the system inefficient. Thus, in ode to ealize an acceptable and efficient system, it is impotant to know chaacteistics of comfotable deceleation behavio and apply them to deceleation assistance system. As a pionee in deceleation behavio of ca dive, Lee [1] developed theoetical famewok of dives longitudinal contol based on TTC (Time-To-Collision) associated with visual infomation. Kondoh et al. investigate the isk peception and showed that it can be epesented by TTC and THW(Time-Headway) [2]. Isaji et al.[] and Wada et al.[4] have poposed a pefomance index of appoach and alienation, KdB as a model of dive s peceptual isk of a peceding vehicle and its anothe vesion, KdB_c based on aea change of peceding vehicle on dive s etina. These indices have been applied to modeling of baking behavios of expet dives [5]. Kitajima et al. have suveyed such evaluation indices concening ea-end collision isk [6]. On the othe hand, thee ae eseaches concening design and evaluation of collision avoidance system and Manuscipt eceived Mach 1, 29 T. Wada is with Kagawa Univesity, Takamatsu, , Japan (phone: ; fax: ; wada@ eng.kagawa-u.ac.jp). S. Doi, and S. Hiaoka ae with Kagawa Univesity, Takamatsu, , Japan ( sdoi@eng.kagawa-u.ac.jp). ACC(Adaptive Cuise Contol) system. Fo example, Goodich et al. [7] chaacteized the behavio in a phase plane of TTC vs. THW. Baeket et al. have evaluated efficacy of ACC based on Gipps model that is a ca-following model in taffic engineeing [8]. Hiaoka et al. deived ca-following model fo ealizing comfotable ACC system by applying concept of minimum jek model to longitudinal vehicle behavio [9]. Suzuki et al. poposed a method to estimate dive status in ca following situation and its application to dive assistance system [1]. It is impotant to intoduce dive s peceptual isk descibed befoe into its design of such dive assistance systems in ode to ealize comfotable and secue system. To implement this concept, we have poposed a deceleation contol method of automobile based on the peceptual isk [11]. In this pape, a bake assistance system will be poposed fo peventing ea-end cash based on an expet dive's deceleation model deived fom dive s peceptual isk. Initiation timing of bake assistance will be detemined by dive s bake initiation timing model. Final taget status of two vehicles, say, convegence distance by the baking system will be detemined based on dive s isk model. Finally, deceleation pofile connecting the bake initiation timing and final taget status will be detemined by dive deceleation patten model. Validity of the poposed contol method will be shown by the expeiments using a diving simulato. II. PROBLEM DESCRIPTION Suppose that a dive follows a ca in the same lane as shown in Fig.1.Rea-end cash occus when the dive does not notice the appoach of the peceding ca due to dive s eos etc. In such situation, ea-end cashes can be educed by detecting dangeous situation as ealie as possible and stating to deceleate automatically. To avoid collision, assistance system need to stat deceleates ealie than emegency avoidance system such as so-called pe-cash safety system. One of difficulties to ealize such system is how to pevent dive s annoyance. Gap D Vo Fig.1 Ca Following Situation Vp

2 In ode to ealize such system, the following thee V t V t V t d (2) questions need to be solved at least. ( ) p ( ) o ( ) D(t) dt Q1) When to initiate automatic deceleation contol Q2) How to detemine deceleation patten of the system Q) How to detemine final taget status of two vehicles On the othe hand, status of the two vehicles can be descibed by gap between two vehicle D, velocity of following vehicle Vo, and velocity of peceding vehicle Vp. Thus, the thee questions above need to be solved by specifying a set of state vaiable [D, Vp, Vo] fo each question. Fo example, we need to solve how to define dange status dange to stat deceleation assist and how to define taget convegence status conv(fig.2). In this pape, we addess the questions by intoducing dive s peceptual isk to educe dive s annoyance and anxiety against the system. Fo this pupose, dive s peceptual isk also needs to be epesented by state vaiable [D, Vp, Vo]. Initiation of deceleation assist Safe status Dangeous status dange Fig. Visual Input on Retina [] We call this vaiable K db pefomance index fo appoach and alienation at the moment of the dive s opeation such as deceleation and acceleation. Index K db is inceased when the peceding ca is appoaching elatively to the following ca as simila as incease of the dive s visual input. K db is inceased when the dive does not eact to this egadless of cause of isky conditions such as low aousal level, inattention o othe easons depending on dive s status. It has been shown that K db can disciminate between baking behavios of nomal safe diving and those in cash accidents that ae extacted fom mico data of cashes [], [4]. In addition, it has been also shown that KdB can be a tigge to tansit following mode to deceleation mode in the case that Taget convegence dive s following behavio is modeled by mode tansition status conv model based on hybid dynamical system [1]. Fig.2 Schematic Image of Tajectoy of State Vaiable of two vehicles In addition, anothe peceptual isk index K db_c has been in Deceleation Assistance System poposed as eq.() by intoducing effect of changes of peceptual isk by peceding vehicle s velocity into account III. DECELERATION BEHAVIOR MODEL OF EXPERT DRIVERS and it has been shown that it can fomulate bake initiation BASED ON PERCEPTUAL RISK timing [5]. A. Index of Peceptual Risk of Poximity K db _ c (a) Suppose that a ca follows a peceding ca in the same lane V av 7 as shown in Fig.1. In such situation, the dive evaluates the 1 log 1 ( 4 1 p )sgn( V av p ) isk against appoach of the peceding ca appopiately and 7 D () ealizes safe diving by opeating pedals and a steeing wheel ( 4 1 ( V av p ) / D 1) based on the peceived esults. So fa, we have hypothesized ( ( V av that dives detect the appoach of the peceding ca and p ) / D 1) ecognize the isk by its aea changes on the etina as shown in Fig. and detemine the opeation of deceleation based on it and a peceptual isk index K db has been deived as eq.(1) B. Model of Expet Dive s Deceleation Patten [],[4]. ModelofDeceleationPofile K db Tsuu et al.[12] and Wada et al.[11] showed that 7 1 log V )sgn( V) deceleation patten of expet dives can be chaacteized 1 ( 4 1 using isk index KdB as follows based on the esults of the (1) expeiments with eal cas (Fig.4). D ( V / D 1) ( V / D 1) P1) Index K db is changed with the same slope dk db/dd=dk db(t bi)/dd as in phase I o constant slope phase in Fig.4. P2) Constant deceleation is held afte peak deceleation whee D denotes gap between two vehicles. Relative velocity V is defined as eq.(2) using velocity of the peceding vehicle V p, and velocity of the following vehicle V o. until V =. as in phase II o constant deceleation phase in Fig.4.

3 K db Relative acceleation Phase II (constant deceleation) baking behavio of the following ca s dive. Based on the Phase I (constant slope) assumption, substituting v (t bi ) into eqs.(7) and (8) dk db / dd Bake initiation point leads to eqs.(9) and (1), espectively. dk db (t bi ) / dd K db without V 2 t (9) V (t) bake D(t) ) ( ) D(t bi D(t p ) D(t bi ) Gap D V (t bi ) V (t p ) V (t) D D (t bi ) (t) exp (D(t) D(t bi )) D(t bi ) V (t bi ) d (t) exp (1 d (t)) Fig. 4 Schematic image of expet dive s deceleation model (1) whee d(t)=d(t)/d(t bi). Fom eq.(9), dv /dt eaches at zeo when V = othewise dv /dt always takes positive value, say, deceleation. In addition, fom eq.(1), V Deceleation Model of Constant slope phase eaches at zeo when D goes to zeo othewise V Expet dive s deceleation behavio was modeled by always takes negative value because v (t bi) < is assumed. Fom these esults, the deived constant slope featue(p1) and the peak hold featue (P2). The deceleation pofile esults in collision with V = unde the peak hold featue is difficult to be installed in the automatic given assumptions as long as the calculated deceleation can baking system due to lack of obustness against situation be geneated, that is, the state is uniquely conveged to its changes. Thus, let us focus on constant slope featue fo applying deceleation pofile geneation method. equilibium point [V, D] T = [, ] T. Fig.5 illustates calculated esults of eqs.(9) and (1) with Suppose that we deal with only appoaching condition V because we ae consideing deceleation assist system. And (t bi)=-2km/h without elative deceleation until bake assume that V / D 1 is satisfied. In such case, initiation. Two lines in each gaph show D(t bi)=25m and 5m. Vey smooth deceleation pofile can be obtained with only definition of KdB of eq.(1) can be ewitten as eq.(4). simple calculation of eq.(9). As the esults, ou model can geneate vey smooth and V (t) K (t) 1 log (4) safe(collision-less) deceleation pofile with simple db 1 D (t) calculation but without any complex calculation such as solving optimal poblem. Diffeentiating K db by gap D yields D =5m D =25m dk (t) 1 V (t) 1.5 db. (5) 1 dd(t) ln1 V 2 (t) D(t).5 Then P1 can be witten as eq.(6). Deceleation dot V [m/s 2 ] Relative velocity V [m/s] dk db (t) dk db (t bi ) (6) dd dd 4 Substituting eq. (5) into eq. (6) and solving by elative 2 acceleation leads to deceleation pofile model eq.(7). V (t) V (t bi ) V 2 (t) (7) D(t) D(t bi ) V 2 (t bi ) Gap D [m] By integating eq.(7) by time yields pofile of elative Fig. 5 Deceleation pofile of constant slope featue velocity as eq.(8). C. Model of Expet Dive s Deceleation Timing V (t) V (t bi ) D (t) exp V (t bi ) (D(t) D(t )) We have analyzed expet dives baking timing with expeiments with eal cas and it has been shown that bake D t V 2 D(t ) bi t judgment line eq.(11) can descibe timing of expet dive ( bi ) ( bi ) bi based on the index KdB_c. (8) Constantelativevelocitysituation (V,V p, D) K db _ c (a) b log 1 D c (11) Fo the sake of simplicity, we deal with the situation The coefficients a, b, and c ae detemined so that the appoaching to a peceding ca diving with a constant appoximated eo of the equation is minimized in tems of velocity. In this situation, elative deceleation is zeo until

4 least squaes. Fo the expeimental esults with test dives, a=.2, b=-22.66, c=74.71 wee obtained. It has aleady been shown that the judgment line of bake initiation can disciminate between nomal safe diving and mico data of cashes vey well. Pobability that the plots fo the nomal diving wee located in the uppe aea than the line is.694. On the othe hand, fo the cash data, pobability that the cash data was located lowe than the line is [5]. Function (V, Vp, D) defined in eq.(11) can be undestood as dive s peceptual isk fo collision. Eq.(11) with assumption of V av p yields eq.(1). V av p (V,Vp, D) 1log 1 (4 1 7 ) blog 1 D c (1) D Hee, let us conside a method to detemine the taget conveged status by specifying dive s peceptual isk at the IV. DECELERATION CONTROL METHOD final status. Namely, the dive s isk at the conveged status FOR COLLISION AVOIDANCE BASED ON PERCEPTUAL RISK is specified as eq.(14) by taking safe magin d into account. The poposed system aims that the vehicle equipped with the conv {[V,V p, D] (V,V p, D) d} (14) system stats to deceleate automatically and avoid collision if the dive does not deceleate o deceleates insufficiently even in high isk situation against the peceding vehicle by dive s failue etc. In ode to ealize effective system, bake initiation timing, the taget conveged status, and deceleation pofile play impotant oles. Especially, automatic bake should stat as ealy as possible in the case of high isk situation to ealize smooth and safe deceleation as long as the dive does not feel discomfot. Fo this poblem, we popose a new contol method by intoducing dive s peceptual isk. Now, also assume that V = at the conveged status. Theefoe, conveged gap satisfying eq.(14) is calculated as eq.(15) given V= and cuent Vp. 1 D cd 1 b av p (15) Namely, conveged gap is detemined by specifying peceding ca s velocity Vp. As seen fom equation, D conv= at V p=. So, eq.(16) is deived by adding gap offset D>. A. Detemination Method of Bake Initiation 1 In the pevious section, dive s bake initiation timing was c d b 7 modeled as bake judgment line. Hee, a method is poposed D conv av p D (16) to apply the model to bake initiation judgment fo automatic baking system. Bake judgment model obtained in the pevious section is an aveaged esult of dive s bake By setting taget conveged gap as eq.(16), conveged status initiation. Thus, dives might ely on the system excessively can be detemined as [V, V p, D] T = [, V p,d conv] T, (V,Vp, D) d is ealized. and do not act any baking because the system stats to bake automatically just when the dive will stat bake if the C. Geneation Method of Deceleation Patten model is employed as bake initiation algoithm without any Let us conside a way to geneate deceleation patten change and it woks pefectly. In addition, thee ae based on the fomulated expet dive s deceleation pofile individual diffeences in bake initiation timing. Fo example, P1, say constant slope featue as eq.(1). Namely, velocity aggessive dives stat to bake in moe isky situations. Thus, contol based on eq.(1) is employed. It should be noted that it is impotant to take individual diffeences of bake the pofile calculated by eq.(1) has a equilibium point initiation into account in bake initiation judgment to avoid [V, D] T =[, ] T. Thus, we need to have a way to change the discomfot. equilibium to [V Theefoe, bake assist contol is initiated when the state, D] T = [, D conv] T. Let us define vaiable as eq.(17). ente the dangeous status define by eq.(12) by adding an offset of the line c to eq.(11) as follows: (t) D(t) D conv D (t) (17) D tbi D conv D tbi Replacing d(t) by this (t) yields a new desied velocity dangeous {[V,V p, D] (V,V p, D) c} (12) pofile eq.(18). whee c is detemined by taking individual diffeence into V(t) V (t bi ) (t) exp (1 (t)) (18) account. Let us conside chaacteistics of eq.(18). Diffeentiating B. Detemination Method of Final Taget Status eq.(18) by time with assumption that the peceding vehicle Final conveged status of two vehicles afte collision does not deceleate yields eq.(19). dv(t) avoidance by deceleation assist is impotant because it V (t bi ) 2 (t)(1 (t)) exp (1 (t)) (19) dt affects dive s ecoveing behavio afte the assist and peipheal taffic flow especially fo the system that woks Following ca deceleates when (1(t)) is satisfied duing elatively ealie stage. In this pape, the final taget because V (t bi ) <. In addition, 1(t) means status will be detemined based on dive s peceptual isk. deceleation of the following ca in the case of appoaching

5 status V< because d (t) V is satisfied. seen fom the figue, the conveged gap in Fig.7-(a)with dt D tbi D conv lage peceding ca velocity is geate than that with smalle Consequently, the following ca always deceleates in appoaching condition V< and the equilibium point is epesented as [V, ] T =[, ] T. peceding vehicle D [m] dot Vo [m/s2] 25 2 D. Concept of Automatic Baking System Consequently, the following contol method has been obtained fo automatic baking system fo collision avoidance (Fig.6): 1) (V, V p, D) is calculated in eal-time fom measued V (t), D(t) and V p(t) o V o(t). Bake contol stats when the status is judged as dangeous status dangeous by eq.(12). 2) Desied elative velocity can be detemined by the pofile model eq.(18). ) The bake contol teminates if V >=. Acceleation command fom the given velocity pofile is geneated by the following simple method as an example: d G k p (V (D) V (t)), (2) whee k p is feedback gain. Please note that in the poposed system, D can be measued by a milliwave ada equipped with the ca and V can be obtained by numeically diffeentiating the measued D. Velocity Vp can be obtained by V + V o given V o. Stat Bake Judgment Bake stat Deceleation contol V? End Y Fig. 6 System flow of automatic baking system E. Simulation Results of Poposed Automatic Baking System In ode to show the effectiveness of the poposed baking method, some numeical simulations ae pefomed with the sequences given in Fig.6. Fig7 illustates the behavio of the poposed contol method in appoaching with a constant elative velocity. Suppose that the velocity of the following ca is Vo=8km/h fo both conditions. Fig.7-(a) and (b) illustate the esults with velocity of the peceding ca ae 4km/h and 6km/h, espectively. As seen in both figues, it is found that smooth velocity pofiles ae ealized and they avoid the collision. As same as the esults of the method poposed in liteatue [11], deceleation is elatively inceased apidly just afte the bake initiation, and then smoothe pofile ealizes the taget velocity. In addition, as N Gap D [m] Gap D [m] Time t [s] (a) Vp=4km/h, Vo=8km/h D [m] 25 dot Vo [m/s2] Time t [s] (b) Vp=6km/h, Vo=8km/h Fig. 7 Simulation esults V. EXPERIMENTS USING DRIVING SIMULATOR A fixed-base diving simulato developed by Kagawa Univesity was utilized fo the expeiments (Fig.8). A 1inch sceen and two 8inch sceens ae located in font of the cockpit. Distance fom dive s eyes to the main sceen is 2.m in depth. Visual angle by the thee sceens is about 14deg. Vehicle motion is calculated by vehicle dynamics simulation softwae CaSim based on dive s opeation Expeimental scenaio was ca following situation in a lane as shown in Fig.1. A following ca with constant velocity appoached to the peceding ca that dives in a constant velocity. Following ca always dives faste than the peceding ca. Paticipants sit on the dive s seat and take diving postue and step on the gas pedal even though the opeation is not eflected to the vehicle motion and the ca dives at constant velocity automatically. Afte that, the following ca stated to deceleate automatically based on the poposed contol method. As the expeimental conditions, the peceding ca velocity was Vp=4, 6, 8km/h and thee ae thee conditions fo elative velocity as V=-2, -4, -6km/h fo each Vp condition. Ode of the expeimental conditions is andomized. Paticipants wee obseved deceleation of the following vehicle by the poposed contol method and asked to evaluate subjectively the conveged status, say, the conveged gap of two vehicles afte temination of the deceleation contol based on the five levels of 1) nea, 2)slightly nea, ) good, 4)slightly fa, and 5) fa afte each tial. Paticipants wee five male students of Kagawa Univesity of 21 to 24 ys. Paametes in the contol method wee set as c= d=. The offset fo the conveged gap was set as D=5m based on the eheasal expeimental esults Velocity Vo [m/s] Velocity Vo [m/s]

6 PC Pojecto Encode Encode Encode Count 1 inch Sceen Steeing Acceleato Bake Fig. 8 Diving Simulato Fig.9 shows subjective evaluation esults of all paticipants. Fo almost all conditions, the paticipants evaluated as good. Thee was some paticipants who evaluated slightly nea in V=-4, -6km/h conditions. This implies that deceleation pofile to the conveged status affects dive s peceptual isk even fo the same conveged status. Investigation of this mechanism will be one of the impotant futue studies. In addition, distance feeling of the diving simulato can be anothe eason of that. In addition, all paticipants have positive comments about the total deceleation pattens fom fee comments. This shows that the poposed method ealize smooth deceleation contol fo oveall Nea Slightly nea Good Slightly fa Fa Velocity [km/h] Fig. 9 Expeimental Results V 8 V p VI. CONCLUSION A new deceleation contol method as a dive assistance system to avoid ea-end collision was poposed based on dive s peceptual isk of collision fo collision avoidance system that woks also in elatively low emegency level. The simulation esults showed that smooth pofile can be geneated appopiately with the poposed method. In addition, fom the expeimental esults, smooth deceleation was ealized to avoid collision with the poposed method and almost good esults wee obtained about conveged status by the subjective evaluation. Howeve, it is found that some paticipants evaluated the same taget status diffeently in the case of the diffeent deceleation pofiles. This implies that the deceleation pofile affects the dive s peceptual isk lagely. Futhe investigation fo pesonal adaptation of the bake initiation timing and conveged status is needed as a futue study because dives ae sensitive to them and it leads to discomfot easily. As anothe futue study, obustness of the method will be investigated including high emegency situation o complex taffic envionment. In addition, influence of the system on the taffic flow will be investigated because the bake assistance system affects diving behavio of following taffics. It is expected that negative effect is small because ou poposed method geneates vey smooth and human-like deceleation pofile. Futhemoe, the method will be applied to othe wide ange of taffic envionment such as cuve deceleation contol etc. ACKNOWLEDGMENT Authos thank to M. Shigeyoshi Tsusumi, a gaduate student of Kagawa Univesity fo geat suppot in the expeiments. This eseach was patially suppoted by the fund fo Kagawa Univesity Young Scientists 29. REFERENCES [1] Lee, D.N., A Theoy of Visual Contol of Baking Based on Infomation about Time-To-Collision, Peception, Vol.5, pp , [2] Kondoh, T. Yamamua, T. Kitazaki, et al., Identification of Visual Cues and Quantification of Dives Peception of Poximity Risk to the Lead Vehicle in Ca-Following Situations, Poceedings of Diving Simulation Confeence Asia/Pacific, CD-ROM, 26. [] Isaji, K., Tsuu, N., Wada, T., Imai, K., Doi, S., and Kaneko, H., Emegency Evaluation by Appoaching in Longitudinal Diection (Fist Repot) Poposal of Pefomance Index fo Appoach and Alienation based on the Dive Opeations-, Tansactions of Society of Automotive Enginees of Japan, vol.8, no.2, pp.25-, 27 (in Japanese) [4] Wada, T., Doi, S., Imai, K., Tsuu, N., Isaji, K., and Kaneko, H., Analysis of Dives Behavios in Ca Following Based on A Pefomance Index fo Appoach and Alienation, SAE 27 Tansactions, Jounal of Passenge Cas Mechanical Systems, SAE pape , pp.6-2, 28. [5] Wada, T., Doi, S., Imai, K., Tsuu, N., Isaji, K., and Kaneko, H., Analysis of Baking Behavios in Ca Following Based on A Pefomance Index fo Appoach and Alienation, Poceedings of IEEE Intelligent Vehicles Symposium, pp , 27. [6] Kitajima, S., Maumo, Y., Hiaoka, T., Itoh, M., Theoetical and Empiical Compaison of Evaluation Indices Concening Rea-end Collision Risk, Poceedings of Intenational Symposium on Advanced Vehicle Contol, Vol.2, pp.62-67, 28 [7] Goodich, M.A., Boe, E.R., Inoue, H.A., Chaacteization of Dynamic Human Baking Behavio with Implications fo ACC Design, Poc. IEEE Conf. on ITS, pp , [8] Baeket, Z., Fanche, P. S., Peng, H., Lee, K., and Assaf, C. A., Methodology fo Assessing Adaptive Cuise Contol, IEEE Tansactions on Intelligent Tanspotation Systems, vol.4, no., pp.12-11, 2. [9] Hiaoka, T., Kunimatsu, T., Nishihaa, O., and Kumamoto, H., Modeling of Dive Following Behavio based on Minimum-jek Theoy, Poceedings. of 12th Wold Congess on Intelligent Tanspot Systems, CD-ROM, 25. [1] Suzuki, T. et al., Modeling and Analysis of Vehicle Following Task based on Mode Segmentation, Poceedings of 9th Intenational Symposium on Advanced Vehicle Contol, pp , 28 [11] Wada, T., Doi, S., Nishiyama, A., Tsuu, N., Isaji,K.,and Kaneko, H. Analysis of Baking Behavio in Ca Following and Its Application to Dive Assistance System, Poc. of Intenational Symposium on Advanced Vehicle Contol, Vol.2, pp , 28 [12] Tsuu, N., Isaji, K., Doi, S., Wada, T., Imai, K., and Kaneko, H., Emegency Evaluation by Appoaching in Longitudinal Diection (Thid epot) An appoach to deceleation behavio based on pefomance index of dive s status-, Poceedings of Annual Confeence of JSAE, Pape No , 26.

7 Rights: 29 IEEE. Pesonal use of this mateial is pemitted. Pemission fom IEEE must be obtained fo all othe uses, in any cuent o futue media, including epinting/epublishing this mateial fo advetising o pomotional puposes, ceating new collective woks, fo esale o edistibution to seves o lists, o euse of any copyighted component of this wok in othe woks. DOI:1.119/IROS Publication Yea: 29 Date of Confeence: 1-15 Oct. 29 Publishe: IEEE Published in: Intelligent Robots and Systems, 29. IROS 29. IEEE/RSJ Intenational Confeence on Page(s): Type: autho vesion