Freely shuttling in complex terrain is a basic skill of multi-legged animals.To make the hexapod robot have omnidirectional motion ability by controlling only one parameter,this paper uses the motion control method ba...Freely shuttling in complex terrain is a basic skill of multi-legged animals.To make the hexapod robot have omnidirectional motion ability by controlling only one parameter,this paper uses the motion control method based on Central Pattern Generator(CPG),maps the output signal of CPG to the foot end trajectory space of the hexapod robot,and proposes an omnidirectional gait controller strategy.In addition,to enable the hexapod robot to adapt to unstructured terrain,an adaptive method based on Dynamic Threshold(DT)is proposed to enable the hexapod robot move in all directions without changing the heading angle in unstructured terrain.Finally,the feasibility of the proposed method is verified by virtual simulation and hexapod robot prototype experiment.Results show that the hexapod robot can omnidirectional motion without changing the heading angle and has good stability in unstructured terrain.展开更多
Reliable foot-to-ground contact state detection is crucial for the locomotion control of quadruped robots in unstructured environments.To improve the reliability and accuracy of contact detection for quadruped robots,...Reliable foot-to-ground contact state detection is crucial for the locomotion control of quadruped robots in unstructured environments.To improve the reliability and accuracy of contact detection for quadruped robots,a detection approach based on the probabilistic contact model with multi-information fusion is presented to detect the actual contact states of robotic feet with the ground.Moreover,a relevant control strategy to address unexpected early and delayed contacts is planned.The approach combines the internal state information of the robot with the measurements from external sensors mounted on the legs and feet of the prototype.The overall contact states are obtained by the classification of the model-based predicted probabilities.The control strategy for unexpected foot-to-ground contacts can correct the control actions of each leg of the robot to traverse cluttered environments by changing the contact state.The probabilistic model parameters are determined by testing on the single-leg experimental platform.The experiments are conducted on the experimental prototype,and results validate the contact detection and control strategy for unexpected contacts in unstructured terrains during walking and trotting.Compared with the body orientation under the time-based control method regardless of terrain,the root mean square errors of roll,pitch,and yaw respectively decreased by 60.07%,54.73%,and 64.50%during walking and 73.40%,61.49%,and 61.48%during trotting.展开更多
基金the National Natural Science Foundation of China No.E1102/52071108National Defense Science and Industry Bureau Stability Support Project No.JCKYS2020SXJQR-04Natural Science Foundation of Heilongjiang Province No.JJ2021JQ0075.
文摘Freely shuttling in complex terrain is a basic skill of multi-legged animals.To make the hexapod robot have omnidirectional motion ability by controlling only one parameter,this paper uses the motion control method based on Central Pattern Generator(CPG),maps the output signal of CPG to the foot end trajectory space of the hexapod robot,and proposes an omnidirectional gait controller strategy.In addition,to enable the hexapod robot to adapt to unstructured terrain,an adaptive method based on Dynamic Threshold(DT)is proposed to enable the hexapod robot move in all directions without changing the heading angle in unstructured terrain.Finally,the feasibility of the proposed method is verified by virtual simulation and hexapod robot prototype experiment.Results show that the hexapod robot can omnidirectional motion without changing the heading angle and has good stability in unstructured terrain.
基金supported by the National Natural Science Foundation of China(Grant Nos.52205059 and 52175050)the Graduate Innovation Special Fund Project of Jiangxi Province,China(Grant No.YC2021-B031).
文摘Reliable foot-to-ground contact state detection is crucial for the locomotion control of quadruped robots in unstructured environments.To improve the reliability and accuracy of contact detection for quadruped robots,a detection approach based on the probabilistic contact model with multi-information fusion is presented to detect the actual contact states of robotic feet with the ground.Moreover,a relevant control strategy to address unexpected early and delayed contacts is planned.The approach combines the internal state information of the robot with the measurements from external sensors mounted on the legs and feet of the prototype.The overall contact states are obtained by the classification of the model-based predicted probabilities.The control strategy for unexpected foot-to-ground contacts can correct the control actions of each leg of the robot to traverse cluttered environments by changing the contact state.The probabilistic model parameters are determined by testing on the single-leg experimental platform.The experiments are conducted on the experimental prototype,and results validate the contact detection and control strategy for unexpected contacts in unstructured terrains during walking and trotting.Compared with the body orientation under the time-based control method regardless of terrain,the root mean square errors of roll,pitch,and yaw respectively decreased by 60.07%,54.73%,and 64.50%during walking and 73.40%,61.49%,and 61.48%during trotting.
