While the nonholonomic robots with no-slipping constraints are studied extensively nowadays, the slipping effect is inevitable in many practical applications and should be considered necessarily to achieve autonomous ...While the nonholonomic robots with no-slipping constraints are studied extensively nowadays, the slipping effect is inevitable in many practical applications and should be considered necessarily to achieve autonomous navigation and control purposes especially in outdoor environments. In this paper the robust point stabilization problem of a tracked mobile robot is discussed in the presence of track slipping, which can be treated as model perturbation that violates the pure nonholonomic constraints. The kinematic model of the tracked vehicle is created, in which the slipping is assumed to be a time-varying pa- rameter under certain assumptions of track-soil interaction. By transforming the original system to the special chained form of nonholonomic system, the integrator backstepping procedure with a state-scaling technique is used to construct the controller to stabilize the system at the kinematic level. The global exponential stability of the final system can be guaranteed by Lyapunov theory. Simulation results with different initial states and slipping parameters demonstrate the fast convergence, robustness and insensitivity to the initial state of the proposed method.展开更多
The small-tracked mobile robots（ STMRs） are small,portable and concealed,and they are widely used in scouting,investigation,rescue and assistance. In this paper,a mechanical model is established based on the multi-b...The small-tracked mobile robots（ STMRs） are small,portable and concealed,and they are widely used in scouting,investigation,rescue and assistance. In this paper,a mechanical model is established based on the multi-body dynamic software RecurD yn,and a control system is simulated through Simulink,including its kinematics model,speed controller,motors＇ model. Associating the mechanical and control model,the cosimulation model is established for STMRs. The co-simulation approach is applied to optimize the motor parameters. A series of experiments are conducted to examine the accuracy of the virtual prototype,and the results demonstrate that the STMR virtual prototype can exactly illustrate the dynamic performance of the physical one.The co-simulation of mechanical model and control model is applied in forecasting and debugging critical parameters,also it provides guidance in defining motor＇s peak current.展开更多
A new parameter identification method is proposed to solve the slippage problem when tracked mobile robots execute turning motions.Such motion is divided into two states in this paper:pivot turning and coupled turning...A new parameter identification method is proposed to solve the slippage problem when tracked mobile robots execute turning motions.Such motion is divided into two states in this paper:pivot turning and coupled turning between angular velocity and linear velocity.In the processing of pivot turning,the slippage parameters could be obtained by measuring the end point in a square path.In the process of coupled turning,the slippage parameters could be calculated by measuring the perimeter of a circular path and the linear distance between the start and end points.The identification results showed that slippage parameters were affected by velocity.Therefore,a fuzzy rule base was established with the basis on the identification data,and a fuzzy controller was applied to motion control and dead reckoning.This method effectively compensated for errors resulting in unequal tension between the left and right tracks,structural dimensions and slippage.The results demonstrated that the accuracy of robot positioning and control could be substantially improved on a rigid floor.展开更多
基金Acknowledgments This work is supported by the National Natural Science Foundation of China （Grant No. 61005092）.
文摘While the nonholonomic robots with no-slipping constraints are studied extensively nowadays, the slipping effect is inevitable in many practical applications and should be considered necessarily to achieve autonomous navigation and control purposes especially in outdoor environments. In this paper the robust point stabilization problem of a tracked mobile robot is discussed in the presence of track slipping, which can be treated as model perturbation that violates the pure nonholonomic constraints. The kinematic model of the tracked vehicle is created, in which the slipping is assumed to be a time-varying pa- rameter under certain assumptions of track-soil interaction. By transforming the original system to the special chained form of nonholonomic system, the integrator backstepping procedure with a state-scaling technique is used to construct the controller to stabilize the system at the kinematic level. The global exponential stability of the final system can be guaranteed by Lyapunov theory. Simulation results with different initial states and slipping parameters demonstrate the fast convergence, robustness and insensitivity to the initial state of the proposed method.
基金Supported by Basic Research Foundation of Beijing Institute of Technology(20130242015)
文摘The small-tracked mobile robots（ STMRs） are small,portable and concealed,and they are widely used in scouting,investigation,rescue and assistance. In this paper,a mechanical model is established based on the multi-body dynamic software RecurD yn,and a control system is simulated through Simulink,including its kinematics model,speed controller,motors＇ model. Associating the mechanical and control model,the cosimulation model is established for STMRs. The co-simulation approach is applied to optimize the motor parameters. A series of experiments are conducted to examine the accuracy of the virtual prototype,and the results demonstrate that the STMR virtual prototype can exactly illustrate the dynamic performance of the physical one.The co-simulation of mechanical model and control model is applied in forecasting and debugging critical parameters,also it provides guidance in defining motor＇s peak current.
文摘A new parameter identification method is proposed to solve the slippage problem when tracked mobile robots execute turning motions.Such motion is divided into two states in this paper:pivot turning and coupled turning between angular velocity and linear velocity.In the processing of pivot turning,the slippage parameters could be obtained by measuring the end point in a square path.In the process of coupled turning,the slippage parameters could be calculated by measuring the perimeter of a circular path and the linear distance between the start and end points.The identification results showed that slippage parameters were affected by velocity.Therefore,a fuzzy rule base was established with the basis on the identification data,and a fuzzy controller was applied to motion control and dead reckoning.This method effectively compensated for errors resulting in unequal tension between the left and right tracks,structural dimensions and slippage.The results demonstrated that the accuracy of robot positioning and control could be substantially improved on a rigid floor.
