Lower-limb exoskeletons can provide paraplegics with the ability to restore gait function. In the community ambulation, the user would frequently meet different floors, doorsills, and other obstacles. Therefore, param...Lower-limb exoskeletons can provide paraplegics with the ability to restore gait function. In the community ambulation, the user would frequently meet different floors, doorsills, and other obstacles. Therefore, parametric gait generation is a significant issue for this kind of exoskeletons. In this paper, a parametric gait online generation approach is proposed, which combines a parametric gait control method with a torque compensation control strategy, based on the state machine. In the torque compensation control, the reference tra- jectories of joint positions are obtained through compensating gravity, inertia, and friction, which is intent on the natural and well-directed source data. Based on the reference trajectories, the parametric gait control method is established, in which the gait can be controlled via three parameters： velocity, step-length, and step-height. Two test cases are performed on three healthy subjects. The results demonstrate that the parametric gait can be online generated smoothly and correctly, meanwhile every variable step can be triggered as users expect. The effectiveness and practicability of the gait generation approach proposed in this paper are validated. In addition, this research is the foundation of autonomous gait planning.展开更多
General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft robots.The concept of modularization brings nove...General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft robots.The concept of modularization brings novel structure,novel locomotion patterns as well as novel control method for soft robots.This paper presents the concept of hierarchical control method for modular soft robot system and a H-configuration pneumatic modular soft robot is designed as the control object.The H-configuration modular soft robot is composed of two basic motion units that take worm-like locomotion principle.The locomotion principle of the basic motion unit is analyzed and the actuation sequence is optimized by evolution strategy in VOXCAD simulation software.The differential drive method is applied to the H-configuration modular soft robot with multi motion modes and vision sensor is used to control the motion mode of the robot.The H-configuration modular soft robot and the basic motion unit are assembled by a cubic soft module made of silicone rubber.Also,connection mechanism is designed to ensure that the soft modules can be assembled in any direction and posture.Experiments are conducted to verify the effect of the hierarchical control method of the modular soft robots.展开更多
基金This work is supported by the National Key R＆D Program of China （Grant 2017YFB1302301）, and the Joint Research Fund （U1613219） between the National Nature Science Foundation of China （NSFC） and Shen Zhen.
文摘Lower-limb exoskeletons can provide paraplegics with the ability to restore gait function. In the community ambulation, the user would frequently meet different floors, doorsills, and other obstacles. Therefore, parametric gait generation is a significant issue for this kind of exoskeletons. In this paper, a parametric gait online generation approach is proposed, which combines a parametric gait control method with a torque compensation control strategy, based on the state machine. In the torque compensation control, the reference tra- jectories of joint positions are obtained through compensating gravity, inertia, and friction, which is intent on the natural and well-directed source data. Based on the reference trajectories, the parametric gait control method is established, in which the gait can be controlled via three parameters： velocity, step-length, and step-height. Two test cases are performed on three healthy subjects. The results demonstrate that the parametric gait can be online generated smoothly and correctly, meanwhile every variable step can be triggered as users expect. The effectiveness and practicability of the gait generation approach proposed in this paper are validated. In addition, this research is the foundation of autonomous gait planning.
基金This work is supported by National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(Grant no.52025054)National Natural Science Foundation of China(Grant no.U1713201).
文摘General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft robots.The concept of modularization brings novel structure,novel locomotion patterns as well as novel control method for soft robots.This paper presents the concept of hierarchical control method for modular soft robot system and a H-configuration pneumatic modular soft robot is designed as the control object.The H-configuration modular soft robot is composed of two basic motion units that take worm-like locomotion principle.The locomotion principle of the basic motion unit is analyzed and the actuation sequence is optimized by evolution strategy in VOXCAD simulation software.The differential drive method is applied to the H-configuration modular soft robot with multi motion modes and vision sensor is used to control the motion mode of the robot.The H-configuration modular soft robot and the basic motion unit are assembled by a cubic soft module made of silicone rubber.Also,connection mechanism is designed to ensure that the soft modules can be assembled in any direction and posture.Experiments are conducted to verify the effect of the hierarchical control method of the modular soft robots.
