In order to guarantee safety and stability during physical human-robot-interaction(p HRI) in the occasion of service or industrial operation, a serial integrated rotary joint with the characteristics of passive and ac...In order to guarantee safety and stability during physical human-robot-interaction(p HRI) in the occasion of service or industrial operation, a serial integrated rotary joint with the characteristics of passive and active compliance is proposed. Passive compliance is achieved by a designed elastic element, such that the compliant joint may minimize large force which occurs during accidental impacts and, further, may offer more accurate and stable force control and a capacity for energy storage. Meanwhile, the modeling of the compliant joint is comprehensively analyzed, including the effect of the motor model on the overall control system. In order to realize the active compliance, a new method of impedance control is proposed. On the basis of PD control, a more compliant impedance controller is introduced. Experimental results show that the serial integrated rotary joint can provide more effective safety compliance during physical interaction, which has also been well applied in our designed massage robot and rehabilitation robot.展开更多
Physical activity is a recognized preventive health measure for seniors and an important focus for senior centers. This paper employs the Andersen Behavioral Model to explore increased physical activity and participat...Physical activity is a recognized preventive health measure for seniors and an important focus for senior centers. This paper employs the Andersen Behavioral Model to explore increased physical activity and participation in three types of senior center activities: physical fitness, dance/aerobic classes, and chair exercises. Data were collected in 2006 on 798 and in 2007 on 742 participants at 21 multipurpose senior centers in a large urban county. Logistic regression analysis (PROC RLOGIST in SAS-callable SUDAAN) was employed to predict increased physical activity, with modes of center participation in physical activity as mediating factors. Predisposing and enabling factors predicted both engaging in center-based exercise programs and increases in physical activity;but the strongest predictors of increases in physical activity were needed factors: physician recommendations to increase exercise and to lose weight. Implications are that both SCs and healthcare providers are important to promote physical activity in the older population.展开更多
Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldo...Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldom achieved. Being compliant to external unperceived impacts is cru- cial since it is unavoidable that the slip, modeling errors and imprecise information of terrain will make planned trajectories to be followed with errors and unpredictable contacts. The impedance control gives an inspiration to realize an active compliance which allows the legged robots to follow reference trajectories and overcome external disturbances. In this paper, a novel impedance force/ position control scheme is presented, which is based on Cartesian force measurement of leg＇ s end effector for our hydraulic quadruped robot The simulation verifies the efficiency of the impedance model, and the experimental results at the end demonstrate the feasibility of the proposed control scheme.展开更多
In this paper, a selective activation strategy is studied in order to alleviate the issue of added compliance in the intrinsic cohesive zone model applied to arbitrary crack propagation. This strategy proceeds by firs...In this paper, a selective activation strategy is studied in order to alleviate the issue of added compliance in the intrinsic cohesive zone model applied to arbitrary crack propagation. This strategy proceeds by first inserting cohesive elements between bulk elements and subsequently tying the duplicated nodes across the interface using controllable multi-point constraints before the analysis begins. Then, during the analysis, a part of the multi-point constraints are selectively released, thereby reactivating the corresponding cohesive elements and allowing cracks to initiate and propagate along the bulk element boundaries. The strategy is implemented in Abaqus/Standard using a user-defined multi-point constraint subroutine. Analysis results indicate that the strategy significantly alleviates the added compliance problem and reduces the computation time.展开更多
基金Project(81473694)supported by the National Natural Science Foundation of ChinaProject(2016A1027)supported by the major Project of Zhongshan City,ChinaProject(2016FZFC007)supported by the Intelligent Equipment and Technology of Automation Research and Development Platform,China
文摘In order to guarantee safety and stability during physical human-robot-interaction(p HRI) in the occasion of service or industrial operation, a serial integrated rotary joint with the characteristics of passive and active compliance is proposed. Passive compliance is achieved by a designed elastic element, such that the compliant joint may minimize large force which occurs during accidental impacts and, further, may offer more accurate and stable force control and a capacity for energy storage. Meanwhile, the modeling of the compliant joint is comprehensively analyzed, including the effect of the motor model on the overall control system. In order to realize the active compliance, a new method of impedance control is proposed. On the basis of PD control, a more compliant impedance controller is introduced. Experimental results show that the serial integrated rotary joint can provide more effective safety compliance during physical interaction, which has also been well applied in our designed massage robot and rehabilitation robot.
文摘Physical activity is a recognized preventive health measure for seniors and an important focus for senior centers. This paper employs the Andersen Behavioral Model to explore increased physical activity and participation in three types of senior center activities: physical fitness, dance/aerobic classes, and chair exercises. Data were collected in 2006 on 798 and in 2007 on 742 participants at 21 multipurpose senior centers in a large urban county. Logistic regression analysis (PROC RLOGIST in SAS-callable SUDAAN) was employed to predict increased physical activity, with modes of center participation in physical activity as mediating factors. Predisposing and enabling factors predicted both engaging in center-based exercise programs and increases in physical activity;but the strongest predictors of increases in physical activity were needed factors: physician recommendations to increase exercise and to lose weight. Implications are that both SCs and healthcare providers are important to promote physical activity in the older population.
基金Supported by the National High Technology Research and Development Program of China(863Program)(2011AA041002)
文摘Most existing legged robots are developed under laboratory environments and, corre- spondingly, have good performance of locomotion. The robots＇ ability of walking on rough terrain is of great importance but is seldom achieved. Being compliant to external unperceived impacts is cru- cial since it is unavoidable that the slip, modeling errors and imprecise information of terrain will make planned trajectories to be followed with errors and unpredictable contacts. The impedance control gives an inspiration to realize an active compliance which allows the legged robots to follow reference trajectories and overcome external disturbances. In this paper, a novel impedance force/ position control scheme is presented, which is based on Cartesian force measurement of leg＇ s end effector for our hydraulic quadruped robot The simulation verifies the efficiency of the impedance model, and the experimental results at the end demonstrate the feasibility of the proposed control scheme.
文摘In this paper, a selective activation strategy is studied in order to alleviate the issue of added compliance in the intrinsic cohesive zone model applied to arbitrary crack propagation. This strategy proceeds by first inserting cohesive elements between bulk elements and subsequently tying the duplicated nodes across the interface using controllable multi-point constraints before the analysis begins. Then, during the analysis, a part of the multi-point constraints are selectively released, thereby reactivating the corresponding cohesive elements and allowing cracks to initiate and propagate along the bulk element boundaries. The strategy is implemented in Abaqus/Standard using a user-defined multi-point constraint subroutine. Analysis results indicate that the strategy significantly alleviates the added compliance problem and reduces the computation time.
