Multi Agent Protocol For Cooperative Overtaking Assistance .

2018 International Conference on Electrical Engineering and Computer Science (ICEECS)Multi Agent Protocol for Cooperative OvertakingAssistance SystemEmir HusniSchool of Electrical Engineering andInformaticsInstitut Teknologi BandungBandung, Indonesiaehusni@lskk.ee.itb.ac.idNoor Cholis Basjaruddin*)Department of Electrical EngineeringPoliteknik Negeri BandungBandung, Indonesianoorcholis@polban.ac.idKuspriyantoSchool of Electrical Engineering andInformaticsInstitut Teknologi BandungBandung, Indonesiakuspriyanto@yahoo.comYoga PriyanaSchool of Electrical Engineering andInformaticsInstitut Teknologi BandungBandung, Indonesiayoga@lskk.ee.itb.ac.id(WAVE). Some WAVE researches has been conducted by [9]and [10].Abstract—Development of vehicular communicationsystems and multi agent system allow the use of active safetydevices to have the ability cooperative like CooperativeOvertaking Assistance System (COAS). Some COASs ondifferent vehicles can cooperate with a goal to improving safetyand ride comfort indexes. COAS work by using the V2Vcommunication which is WAVE (wireless access in vehicularenvironment). Data exchange between vehicles (agents) isgoverned by the multi agent protocol designed specifically forthe implementation of the cooperative overtaking. This paperpresents the multi agent protocol for the purposes of the COASthat are designed with the WAVE architecture environment. Anefficient protocol shows that it can improve the safety index ofCOAS, length of overtaking time, and total time for dataexchange.II. RESEARCH METHODA multi-agent protocol has been developed is specificallyto address cooperative overtaking process involving threeagents (vehicles). The protocols were developed to obtain amore efficient protocol in time usage for communicationamong agents.A. Overtaking in Connected VehiclesOvertaking maneuver can be done by four techniques,namely accelerate/normal, flying, 2 , and piggy backing[11]. Phases of accelerative overtaking are approaching,tailgating, lane changing, passing, and lane returning. At thetime of tailgating the driver will make the decision whether itcan overtake or not. The calculation of the overtakingintention in the COAS will be done automatically by utilizingdata from the sensor [12]. In COAS, the data for overtakingintention calculation are not only from the sensors, but alsofrom a communication device which is the WAVE. The dataexchanged via the WAVE are sourced from the GPS asillustrated in Fig. 1.Keywords—cooperative overtaking assistance system,wireless access in vehicular environment, agent protocolI. INTRODUCTIONThree important factors which are the cause of trafficaccidents is human, vehicle, and environment. Human error isthe main cause of 94% accidents that occur on the traffic [1].The high number of traffic accidents caused by human errorcan be reduced by improving the vehicle technology. The useof safety technology and vehicle technology refinement ingeneral proven can reduce the number of the accident [2].By 2020 the Intelligent Driver Assistance Systems (IDAS)or Advanced Driver Assistance Systems (ADAS) who has theability to be cooperative began to be used [3]. In the same yearalso estimated the driverless vehicle will start marketed [4].Both of these technologies are expected to have a majorcontribution in reducing the number of casualties resultingfrom traffic accidents [5].Fig. 1. Illustration of overtaking in connected vehicleenvironmentCooperative IDAS can be realized due to the developmentof Vehicular Ad hoc Networks (VANET) that enables dataexchange between vehicles every 20 ms with a radius of 1000m [6]. VANET technologies allow a vehicle to infrastructure(V2I), vehicle to vehicle (V2V), and vehicle-to-pedestrian(V2P) communication. Much research has been conducted onVANET [7] and [8]. One of VANET architecture that iscurrently widely used in the development of IDAS is WirelessAccess in Vehicular EnvironmentsThrough broadcast mode of WAVE, the vehicles areexchanging information containing: a vehicle ID, position,speed, acceleration, direction, and type of vehicle. Based onthese data, the EV vehicle can calculate overtaking intention.If the value of overtaking intention is 1 the EV will overtake,but if the value is 0 then the EV will continue tailgating untilthere is a chance of overtaking.53

B. Cooperative OvertakingIn broadcast mode the message contains information asshown in the Table I. This message is sent every 20 ms in 50Hz data rate [16]. The unicast mode is used for specialpurposes, namely for the delivery of messages related tosafety. One example of the use of this mode for active safetydevice is sending safety messages in the CooperativeAdaptive Cruise Control (CACC) [17].Cooperative overtaking is overtaking which is conductedthrough the mechanism of cooperation among severalvehicles with the aim of improving the safety and ridecomfort. Illustration of cooperative overtaking on thebidirectional road can be seen in Fig. 2. Ego Vehicle (EV) isthe overtaker vehicle, Partner Vehicle (PV) is an overtakenvehicle, and Obstacle/Oncoming Vehicle (OV) is a vehiclecoming from the opposite eTABLE I FORMAT AND DATA SOURCEFormatData yyyyss.sshhh.hhvvGPS (UTC)MAC OBUGPS (DD format)GPS (m/s)GPS (degree)MAC OBUD. Protocol DesignFig. 2. Overtaking on bidirectional roadFigure 2(A) shows when the EV has decided to overtakethe PV, then the EV starts lane changing, but the OV increasespeed. If the increased Speed of the OV is not taken intoaccount when calculating the overtaking intention, the EVcan be failed to overtake and collided with OV or PV.Through the cooperation mechanism, the EV can request tothe OV to maintain or reduce speed so that the EV is able toovertake PV safely.In Figure 2(B) shows the situation when the EV is going togo back to the original lane. At the time when the EV ispassing by the PV, the PV may increase the speed. If thissituation is not taken into account when calculating theovertaking intention by the EV, the EV can be failed back tothe original lane because it is obstructed by the PV and theEV could be colliding with the OV. The mechanism ofcooperation can address this issue by the asking the PV not toadd the speed so that the EV can go back to the original lanesafely without colliding with the OV.Cooperation between vehicles in an overtaking process canbe done at the calculation of the overtaking intention or whenthe overtaking maneuver is executed [13]. In this study, wedesigned a protocol that is used during the execution of theovertaking maneuver.The protocol was designed referring to the protocol whichis used in the cooperative multi agent system (CMAS)environment. In the CMAS environment, the agentscommunicate using a language known as an agentcommunication language (ACL). Almost all ACLs aredeveloped from the speech act theory, such as TheKnowledge Query and Manipulation Language (KQML) andThe Foundation for Intelligent Physical Agents (FIPA) ACL[18]. We have developed special predicates and argumentsused in vehicle agents such as: maneuver passing,sequence behind, and cooperative slower. The design of theprotocol for cooperative overtaking can be seen in Fig 4.In conventional protocol, the EV will go back into theoriginal lane after the PV and OV agrees to keep the speed.The situation is becoming very dangerous when there is adelay in communications so that the EV will be late return tothe lane and very likely collided with the OV. In efficientprotocol, the EV is allowed to be back into the original laneif the condition already permits, even the approval messagesfrom PV and OV are not yet accepted by EV.An example of the use of ACL in the protocol that we havedesigned can be seen in Table II.C. Message Spreading through WAVEThe dissemination of the message in WAVE is done intwo modes, namely a broadcasting mode and a unicastingmode. In the broadcasting mode, the delivery of trafficinformation in general will be periodically, such as thelocation of other vehicles [14]. Illustration of thebroadcasting mode can be seen in Fig. 3 [15].SenderTABLE II AN EXAMPLE OF THE USE ACL IN L(request:sender (00:00:00:00:00:01):receiver (00:00:00:00:00:02):content"cooperation (keepSpeed)":language fipa)Fig. 3. Broadcast mode in WAVE54

Fig. 4. Protocol for cooperative overtakingIII. RESULTS AND ANALYSISlarge delays on the PTT and the length of overtaking time(LOT) can be seen.In the span of a small delay, it can be seen that the safetyindex is not affected by the delay either IOS uses protocolsefficiently or inefficiently. If the delay is above 1 second, itcan cause of impairment of the SI and can harm the processof overtaking. The influence of large delays can be overcomewith efficient protocol. Fig. 7 shows that the PTT value of theefficient protocol has lower value than the PTT value of theinefficient protocols. In addition to raising the safety index onefficient protocols, they can also shorten the length ofovertaking time as shown in Fig. 8.Protocol testing is performed using the simulator, whichwas developed specifically using BDI agent-basedprogramming. We define the protocol total time (PTT) whichmeans the entire time, which is used for data exchange forovertaking and is calculated by (1).PTT Nbc.Cbc Nuc.Cuc(1)where,Nbc : number of broadcast messagesCbc : average message delivery time in broadcastcommunicationNuc : number of unicast messagesCuc : average message delivery time in unicastcommunicationTesting protocol performed on two conditions, namelysmall delays (under the maximum latency of WAVE, 100ms)and large delays (above maximum latency of WAVE). Theeffect of small and large delays on safety index (SI) can beseen in Fig. 5 and Fig. 6. In Fig. 7 and Fig. 8, the effect of55