汽车差动助力转向系统的可拓协调控制
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摘要
根据电动轮汽车各轮扭矩独立可控的特点,改变左右转向轮的驱动力差提供转向助力,实现差动助力转向.考虑到差动助力转向系统对汽车稳定性的影响,利用Carsim/Simulink建立轮毂电机驱动电动汽车模型,设计了两层差动助力转向稳定性可拓协调控制系统.在上层控制器中,根据汽车行驶状态,建立可拓协调控制器,其中将二维可拓集合中的可拓距转换到一维可拓集合中计算,求解关联函数,确定各控制器输出权重.在下层控制器中,采用转向盘转矩直接控制策略,建立差动助力转向控制器;根据可拓域和非域中汽车状态的不同,实现基于横摆角速度和质心侧偏角的切换控制,进而建立横摆力矩控制器;基于二次规划方法对四轮驱动转矩优化分配,并根据所处的值域对3种不同的约束条件进行选择.最后利用Carsim和Matlab/Simulink在不同路面附着系数的双移线工况下进行仿真.仿真结果表明,与差动助力转向系统单独工作时相比,当路面附着系数为0.8时,该控制系统能够提高道路跟踪能力,横向偏差最多减少50%,纵向偏差最多减少30%,横摆角速度、质心侧偏角和侧向加速度明显减小,其均方根值分别优化了54.9%,21.4%和22.3%,改善了汽车操纵稳定性;当路面附着系数为0.4时,该系统能够避免汽车失稳,提高行车安全.
According to the feature that the torque of each wheel for the in-wheel motor drive electric vehicle is independently controllable,the left and right steering wheels' driving force is changed to provide steering power,and the differential drive assisted steering is implemented.Considering the effect on vehicle stability by differential drive assisted steering system,the Carsim/Simulink was utilized to establish the model of the in-wheel motor drive electric vehicle,and a two-layer extension coordinated control system was designed for the stability of automotive differential drive assisted steering system.In the upper-layer controller,according to vehicle driving conditions,the extension coordination controller was established.The extension distance was computed in one-dimensional extension set instead of two-dimensional extension set,so as to solve the correlation function to determine the controllers' output weights.In the lower-layer controller,the differential drive assisted steering controller was established based on steering wheel torque direct control strategy.Then the yaw moment controller was set up based on the switching of yaw rate control and sideslip angle control according to the different conditions of vehicle in the extension domain and non-domain.Next,the optimal drive torque of four wheels was distributed based on quadratic programming and three different constraint conditions were selected according to different domains.The Carsim and Matlab/Simulink were utilized to carry out the simulation under the double lane conditions with different road friction coefficient.The simulation results show that compared with differential drive assisted steering system working alone,when the road adhesion coefficient was 0.8,the control system can improve the road tracking ability that the lateral and longitudinal deviation respectively decrease by 50%and 30%,and the root mean square values of yawing angular velocity,the center of mass of side-slip angle and lateral acceleration were obviously decreased by 54.9%,21.4%and 22.3%respectively;when the road adhesion coefficient was 0.4,the system can avoid vehicle's instability and improve the driving safety.
According to the feature that the torque of each wheel for the in-wheel motor drive electric vehicle is independently controllable,the left and right steering wheels' driving force is changed to provide steering power,and the differential drive assisted steering is implemented.Considering the effect on vehicle stability by differential drive assisted steering system,the Carsim/Simulink was utilized to establish the model of the in-wheel motor drive electric vehicle,and a two-layer extension coordinated control system was designed for the stability of automotive differential drive assisted steering system.In the upper-layer controller,according to vehicle driving conditions,the extension coordination controller was established.The extension distance was computed in one-dimensional extension set instead of two-dimensional extension set,so as to solve the correlation function to determine the controllers' output weights.In the lower-layer controller,the differential drive assisted steering controller was established based on steering wheel torque direct control strategy.Then the yaw moment controller was set up based on the switching of yaw rate control and sideslip angle control according to the different conditions of vehicle in the extension domain and non-domain.Next,the optimal drive torque of four wheels was distributed based on quadratic programming and three different constraint conditions were selected according to different domains.The Carsim and Matlab/Simulink were utilized to carry out the simulation under the double lane conditions with different road friction coefficient.The simulation results show that compared with differential drive assisted steering system working alone,when the road adhesion coefficient was 0.8,the control system can improve the road tracking ability that the lateral and longitudinal deviation respectively decrease by 50%and 30%,and the root mean square values of yawing angular velocity,the center of mass of side-slip angle and lateral acceleration were obviously decreased by 54.9%,21.4%and 22.3%respectively;when the road adhesion coefficient was 0.4,the system can avoid vehicle's instability and improve the driving safety.
引文
1国家制造强国建设战略咨询委员会.《中国制造2025》重点领域技术路线图.北京:电子工业出版社,2015.100-102
2 Murata S.Vehicle dynamics innovation with in-wheel motor.SAE Technical Paper.2011,39:1-6
3 Xiong L,Yu Z,Wang Y,et al.Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation.Vehicle Syst Dyn,2012,50:831-846
4 Ko S,Song C,Kim H.Cooperative control of the motor and the electric booster brake to improve the stability of an in-wheel electric vehicle.Int J Automot Technol,2016,17:447-456
5 Ko S Y,Ko J W,Lee S M,et al.A study on in-wheel motor control to improve vehicle stability using human-in-the-loop simulation.J Power Electron,2013,13:536-545
6 Ren B T,Chen H,Zhao H Y,et al.MPC-based yaw stability control in in-wheel-motored EV via active front steering and motor torque distribution.Mechatronics,2016,38:103-114
7王庆年,王军年,宋世欣,等.差动助力转向系统离线仿真验证.汽车工程,2009,31:545-551
8 Wang J,Wang Q,Jin L,et al.Independent wheel torque control of 4WD electric vehicle for differential drive assisted steering.Mechatronics,2011,21:63-76
9 Li Q,Yu X,Zhang H,et al.Study on differential assist steering system with double in-wheel motors with intelligent controller.Math Probl Eng,2015,2015:1-8
10 Leng B,Xiong L,Jin C,et al.Differential drive assisted steering control for an in-wheel motor electric vehicle.SAE Int J Passeng Cars-Electron Electr Syst,2015,8:2015-01-1599
11杨春燕,蔡文.可拓学.北京:科学出版社,2014.355-357
12熊璐,陈晨,冯源.基于Carsim/Simulink联合仿真的分布式驱动电动汽车建模.系统仿真学报,2014,26:1143-1148
13王军年.电动轮独立驱动汽车差动助力转向技术研究.博士学位论文.长春:吉林大学,2009.93-96
14余志生.汽车理论.第5版.北京:机械工业出版社,2015.144-147
15刘翔宇.基于直接横摆力矩控制的车辆稳定性研究.博士学位论文.合肥:合肥工业大学,2010.57-61
16 Smarandache F.Generalizations of the distance and dependent function in extenics to 2D,3D,and nD.Prog Phys,2012,3:54-61
17任夏楠,邓兆祥.驾驶员理想转向盘力矩特性研究.中国机械工程,2014,25:2261-2265
18宗长富,麦莉,王德平,等.基于驾驶模拟器的驾驶员所偏好的转向盘力矩特性研究.中国机械工程,2007,18:1001-1005
19 Tao T,Su S F.Moment adaptive fuzzy control and residue compensation.IEEE Trans Fuzzy Syst,2014,22:803-816
20 Doumiati M,Victorino A,Lechner D,et al.Observers for vehicle tyre/road forces estimation:Experimental validation.Vehicle Syst Dyn,2010,48:1345-1378
2 Murata S.Vehicle dynamics innovation with in-wheel motor.SAE Technical Paper.2011,39:1-6
3 Xiong L,Yu Z,Wang Y,et al.Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation.Vehicle Syst Dyn,2012,50:831-846
4 Ko S,Song C,Kim H.Cooperative control of the motor and the electric booster brake to improve the stability of an in-wheel electric vehicle.Int J Automot Technol,2016,17:447-456
5 Ko S Y,Ko J W,Lee S M,et al.A study on in-wheel motor control to improve vehicle stability using human-in-the-loop simulation.J Power Electron,2013,13:536-545
6 Ren B T,Chen H,Zhao H Y,et al.MPC-based yaw stability control in in-wheel-motored EV via active front steering and motor torque distribution.Mechatronics,2016,38:103-114
7王庆年,王军年,宋世欣,等.差动助力转向系统离线仿真验证.汽车工程,2009,31:545-551
8 Wang J,Wang Q,Jin L,et al.Independent wheel torque control of 4WD electric vehicle for differential drive assisted steering.Mechatronics,2011,21:63-76
9 Li Q,Yu X,Zhang H,et al.Study on differential assist steering system with double in-wheel motors with intelligent controller.Math Probl Eng,2015,2015:1-8
10 Leng B,Xiong L,Jin C,et al.Differential drive assisted steering control for an in-wheel motor electric vehicle.SAE Int J Passeng Cars-Electron Electr Syst,2015,8:2015-01-1599
11杨春燕,蔡文.可拓学.北京:科学出版社,2014.355-357
12熊璐,陈晨,冯源.基于Carsim/Simulink联合仿真的分布式驱动电动汽车建模.系统仿真学报,2014,26:1143-1148
13王军年.电动轮独立驱动汽车差动助力转向技术研究.博士学位论文.长春:吉林大学,2009.93-96
14余志生.汽车理论.第5版.北京:机械工业出版社,2015.144-147
15刘翔宇.基于直接横摆力矩控制的车辆稳定性研究.博士学位论文.合肥:合肥工业大学,2010.57-61
16 Smarandache F.Generalizations of the distance and dependent function in extenics to 2D,3D,and nD.Prog Phys,2012,3:54-61
17任夏楠,邓兆祥.驾驶员理想转向盘力矩特性研究.中国机械工程,2014,25:2261-2265
18宗长富,麦莉,王德平,等.基于驾驶模拟器的驾驶员所偏好的转向盘力矩特性研究.中国机械工程,2007,18:1001-1005
19 Tao T,Su S F.Moment adaptive fuzzy control and residue compensation.IEEE Trans Fuzzy Syst,2014,22:803-816
20 Doumiati M,Victorino A,Lechner D,et al.Observers for vehicle tyre/road forces estimation:Experimental validation.Vehicle Syst Dyn,2010,48:1345-1378