Multi-joint manipulator systems are subject to nonlinear influences such as frictional characteristics,random disturbances and load variations.To account for uncertain disturbances in the operation of manipulators,we ...Multi-joint manipulator systems are subject to nonlinear influences such as frictional characteristics,random disturbances and load variations.To account for uncertain disturbances in the operation of manipulators,we propose an adaptive manipulator control method based on a multi-joint fuzzy system,in which the upper bound information of the fuzzy system is constant and the state variables of the manipulator control system are measurable.The control algorithm of the system is a MIMO(multi-input-multi-output)fuzzy system that can approximate system error by using a robust adaptive control law to eliminate the shadow caused by approximation error.It can ensure the stability of complex manipulator control systems and reduce the number of fuzzy rules required.Comparison of experimental and simulation data shows that the controller designed using this algorithm has highly-precise trajectory-tracking control and can control robotic systems with complex characteristics of non-linearity,coupling and uncertainty.Therefore,the proposed algorithm has good practical application prospects and promotes the development of complex control systems.展开更多
Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors an...Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors and periphery processing circuit, robotics sensitive skin can in real-time provide existence and distance information about obstacles for robots within sensory areas. The methodology of designing sensitive skin and the algorithm of a mass of IR data fusion are presented. The experimental results show that the multi-joint robot with this sensitive skin can work autonomously in an unknown environment.展开更多
This paper presents a multi-joint desensitization design(MDD)-based assembly distribution and precision evolution for industrial parallel robots.The optimization of a-UPS/S parallel robot is demonstrated through the o...This paper presents a multi-joint desensitization design(MDD)-based assembly distribution and precision evolution for industrial parallel robots.The optimization of a-UPS/S parallel robot is demonstrated through the optimization of its performance index and precision performance,achieved through the construction of a global error sensitivity.The precision degradation law for independent sources of uncertainty is introduced,and the accelerated degradation after multiple repairs is considered to establish a source-split maintenance yield model to formulate an optimized operation and maintenance strategy.Experiment demonstrates that the MDD method significantly enhances the precision and reliability of the equipment.Compared with that in the pre-optimization stage,the lifetime of the equipment is extended by 38.88%,while the cost remains unchanged.In addition,the effectiveness of MDD in additive manufacturing is demonstrated through an industrial bending pipe case.展开更多
Purpose This study had 2 primary aims(1)compare the effects of multi-joint vs.single-joint lower body exercise on regional muscular development of the quadriceps;and(2)compare the effects of exercises performed at dif...Purpose This study had 2 primary aims(1)compare the effects of multi-joint vs.single-joint lower body exercise on regional muscular development of the quadriceps;and(2)compare the effects of exercises performed at different knee-joint angles on hypertrophy of the triceps surae.Methods Thirty young,resistance-trained participants unilaterally performed a combination of the following lower body exercises:leg press,leg extension,straight-leg toe press,and seated calf raise.The participants’right legs were randomly allocated to perform 1 of the following 4 conditions:(1)leg press and straight-leg toe press;(2)leg-press and seated calf raise;(3)leg extension and straight-leg toe press;(4)leg extension and seated calf raise.Based on the allocated condition,the contralateral leg performed the other 2 exercises included in the protocol.Training was carried out twice per week on non-consecutive days for 8 weeks.Results Point estimates for the rectus femoris outcomes favored the single-joint exercise intervention with posterior prob-abilities ranging from 0.910≤P≤0.990.In contrast,point estimates for the vastus lateralis outcomes favored the multi-joint exercise intervention with posterior probabilities ranging from 0.875≤P≤0.994.Regarding the triceps surae,the point estimate favored straight-leg plantar flexion for muscle thickness of the medial gastrocnemius(P=0.991),with equivocal results observed for the lateral gastrocnemius and soleus.Conclusion Our findings indicate that exercise selection can influence regional hypertrophy of the muscles of the lower limbs and evidence of differences can be measured within 8 weeks.展开更多
基金the project of science and technology of Henan province under Grant No.14210221036.
文摘Multi-joint manipulator systems are subject to nonlinear influences such as frictional characteristics,random disturbances and load variations.To account for uncertain disturbances in the operation of manipulators,we propose an adaptive manipulator control method based on a multi-joint fuzzy system,in which the upper bound information of the fuzzy system is constant and the state variables of the manipulator control system are measurable.The control algorithm of the system is a MIMO(multi-input-multi-output)fuzzy system that can approximate system error by using a robust adaptive control law to eliminate the shadow caused by approximation error.It can ensure the stability of complex manipulator control systems and reduce the number of fuzzy rules required.Comparison of experimental and simulation data shows that the controller designed using this algorithm has highly-precise trajectory-tracking control and can control robotic systems with complex characteristics of non-linearity,coupling and uncertainty.Therefore,the proposed algorithm has good practical application prospects and promotes the development of complex control systems.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50105002) and Fund of Harbin Institute of Technology (Grant No.HIT.2001.14).
文摘Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors and periphery processing circuit, robotics sensitive skin can in real-time provide existence and distance information about obstacles for robots within sensory areas. The methodology of designing sensitive skin and the algorithm of a mass of IR data fusion are presented. The experimental results show that the multi-joint robot with this sensitive skin can work autonomously in an unknown environment.
基金funded by the China National Key Research and Development Project(Grant No.2022YFB3303303)Key Project of Zhejiang Provincial Natural Science Foundation(Grant No.Z26E050041)State Key Laboratory of Materials Processing and Die and Mold Technology Key Open Fund,China(Grant No.P2024-001).
文摘This paper presents a multi-joint desensitization design(MDD)-based assembly distribution and precision evolution for industrial parallel robots.The optimization of a-UPS/S parallel robot is demonstrated through the optimization of its performance index and precision performance,achieved through the construction of a global error sensitivity.The precision degradation law for independent sources of uncertainty is introduced,and the accelerated degradation after multiple repairs is considered to establish a source-split maintenance yield model to formulate an optimized operation and maintenance strategy.Experiment demonstrates that the MDD method significantly enhances the precision and reliability of the equipment.Compared with that in the pre-optimization stage,the lifetime of the equipment is extended by 38.88%,while the cost remains unchanged.In addition,the effectiveness of MDD in additive manufacturing is demonstrated through an industrial bending pipe case.
文摘Purpose This study had 2 primary aims(1)compare the effects of multi-joint vs.single-joint lower body exercise on regional muscular development of the quadriceps;and(2)compare the effects of exercises performed at different knee-joint angles on hypertrophy of the triceps surae.Methods Thirty young,resistance-trained participants unilaterally performed a combination of the following lower body exercises:leg press,leg extension,straight-leg toe press,and seated calf raise.The participants’right legs were randomly allocated to perform 1 of the following 4 conditions:(1)leg press and straight-leg toe press;(2)leg-press and seated calf raise;(3)leg extension and straight-leg toe press;(4)leg extension and seated calf raise.Based on the allocated condition,the contralateral leg performed the other 2 exercises included in the protocol.Training was carried out twice per week on non-consecutive days for 8 weeks.Results Point estimates for the rectus femoris outcomes favored the single-joint exercise intervention with posterior prob-abilities ranging from 0.910≤P≤0.990.In contrast,point estimates for the vastus lateralis outcomes favored the multi-joint exercise intervention with posterior probabilities ranging from 0.875≤P≤0.994.Regarding the triceps surae,the point estimate favored straight-leg plantar flexion for muscle thickness of the medial gastrocnemius(P=0.991),with equivocal results observed for the lateral gastrocnemius and soleus.Conclusion Our findings indicate that exercise selection can influence regional hypertrophy of the muscles of the lower limbs and evidence of differences can be measured within 8 weeks.
