A force control strategy for position controlled robotic manipulators is presented. On line force feedback data are employed to estimate the local shape of the unknown constraint. The estimated vectors are used to ge...A force control strategy for position controlled robotic manipulators is presented. On line force feedback data are employed to estimate the local shape of the unknown constraint. The estimated vectors are used to generate the virtual reference trajectory for the target impedance model that is driven by the force error to produce command position. By following the command position trajectory the robotic manipulator can follow the unknown constraint surface while keeping an acceptable force error in a manner depicted by the target impedance model. Computer simulation on a 3 linked planar manipulator and experimental studies on an Adept 3, an SCARA type robotic manipulator, are conducted to verify the force tracking capability of the proposed control strategy.展开更多
Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexter...Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexterous design per the requirements of anthropomorphic robots. Underactuated self-adaptive theory is adopted to decrease the number of motors and weight. The fingers of HIT ARhand with multi phalanges have the same size as those of an adult hand. Force control is realized with the position sensor, joint torque sensor and fingertip torque sensor. From the 3D model, the whole hand, with the low power consumption DSP control board integrated in it, will weigh only 500 g. It will be assembled on a BIT-Anthropomorphic Robot.展开更多
This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody sys...This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody system and is studied as such. Dynamic analyses of constrained multibody systems may be obtained using recently developed procedures based upon Kane′s equations and Huston′s methods. These procedures lead to a numerical formulation of the governing equations, thus producing a simulation of the movement of the system. The procedures are applied and illustrated with a two robot system using PUMA 760 and 562 robots. A good agreement is obtained between theoretical and experimental results.展开更多
The essential requirements of the end-effector of large space manipulator are capabilities of misalignment tolerance and soft capture.According to these requirements,an end-effector prototype combining the tendon-shea...The essential requirements of the end-effector of large space manipulator are capabilities of misalignment tolerance and soft capture.According to these requirements,an end-effector prototype combining the tendon-sheath transmission system with steel cable snaring mechanism was manufactured.An analysis method based on the coordinate transformation and the projection of key points of the mechanical interface was proposed,and it was a guideline of the end-effector design.Furthermore,the tendon-sheath transmission system was employed in the capture subassembly to reduce the inertia of the capture mechanism and enlarge the capture space.The capabilities of misalignment tolerance and soft capture were validated through the dynamic simulation in ADAMS software.The results of the capture simulation and experiment show that the end-effector has outstanding capabilities of misalignment tolerance and soft capture.The translation misalignments in radial directions are±100 mm,and angular misalignments about pitch and yaw are±15°.展开更多
We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the imp...We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the improvement of the cared person＇s movement volition and movement abilities. In order to realize safe and human friendly robot care tasks, full body manipulation is an important technology, for which it is necessary to estimate the subject＇s center of gravity from the contact positions and forces with the robot＇s two arms. In this paper, we estimate the center of gravity of object based on the contact point and the contact force estimated by force sensor on both robot arms. The position of gravity center is important to realize care tasks stably. We performed experiments and simulations for the single point contact and dual points contact cases using a cylindrical object. As a result, it is found that although some errors were recognized in the experiments compared with the simulations, the relations between the contact positions and such errors were observed. Such experimental error mainly comes from the difference of shape between the real robot and the model of the robot in simulation.展开更多
A novel 5-DOF exoskeletal rehabilitation robot for upper limbs of hemiplegic patients caused by stroke is proposed in this paper. Its hardware structure is introduced and the control methods are ana- lyzed. To impleme...A novel 5-DOF exoskeletal rehabilitation robot for upper limbs of hemiplegic patients caused by stroke is proposed in this paper. Its hardware structure is introduced and the control methods are ana- lyzed. To implement intelligent and interactive rehabilitation exercises, motion intention of patients＇ up- per limb is introduced into control methods of rehabilitation exercises. In passive motions, according to the character of unilateral impaired, multi-channels surface electromyogram （sEMG） signals of patients＇ healthy arm muscles are acquired and analyzed to recognize the upper limb motions, then drive the robot and assist paralysis ann＇s rehabilitation exercises. In active-resistant motions, because patients are re- covered with some muscle forces and active motion ability after a rehabilitation period, the terminal force loaded on the robot by an impaired arm are estimated with multi-channel joint torque sensors, according to which, the terminal velocity of the robot is controlled to drive the joint motions with a damp controller.展开更多
文摘A force control strategy for position controlled robotic manipulators is presented. On line force feedback data are employed to estimate the local shape of the unknown constraint. The estimated vectors are used to generate the virtual reference trajectory for the target impedance model that is driven by the force error to produce command position. By following the command position trajectory the robotic manipulator can follow the unknown constraint surface while keeping an acceptable force error in a manner depicted by the target impedance model. Computer simulation on a 3 linked planar manipulator and experimental studies on an Adept 3, an SCARA type robotic manipulator, are conducted to verify the force tracking capability of the proposed control strategy.
文摘Nowadays many anthropomorphic robotic hands have been put forward. These hands emphasize different aspects according to their applications. HIT Anthropomorphic Robotic Hand (ARhand) is a simple, lightweight and dexterous design per the requirements of anthropomorphic robots. Underactuated self-adaptive theory is adopted to decrease the number of motors and weight. The fingers of HIT ARhand with multi phalanges have the same size as those of an adult hand. Force control is realized with the position sensor, joint torque sensor and fingertip torque sensor. From the 3D model, the whole hand, with the low power consumption DSP control board integrated in it, will weigh only 500 g. It will be assembled on a BIT-Anthropomorphic Robot.
文摘This paper studies the dynamics of multiarm robots and multirobot configuration. With two or more arms holding an object, one or more closed loops are formed by the arms. The system is then a constrained multibody system and is studied as such. Dynamic analyses of constrained multibody systems may be obtained using recently developed procedures based upon Kane′s equations and Huston′s methods. These procedures lead to a numerical formulation of the governing equations, thus producing a simulation of the movement of the system. The procedures are applied and illustrated with a two robot system using PUMA 760 and 562 robots. A good agreement is obtained between theoretical and experimental results.
基金Project(2006AA04Z228) supported by National Hi-tech Research and Development Program of China
文摘The essential requirements of the end-effector of large space manipulator are capabilities of misalignment tolerance and soft capture.According to these requirements,an end-effector prototype combining the tendon-sheath transmission system with steel cable snaring mechanism was manufactured.An analysis method based on the coordinate transformation and the projection of key points of the mechanical interface was proposed,and it was a guideline of the end-effector design.Furthermore,the tendon-sheath transmission system was employed in the capture subassembly to reduce the inertia of the capture mechanism and enlarge the capture space.The capabilities of misalignment tolerance and soft capture were validated through the dynamic simulation in ADAMS software.The results of the capture simulation and experiment show that the end-effector has outstanding capabilities of misalignment tolerance and soft capture.The translation misalignments in radial directions are±100 mm,and angular misalignments about pitch and yaw are±15°.
文摘We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the improvement of the cared person＇s movement volition and movement abilities. In order to realize safe and human friendly robot care tasks, full body manipulation is an important technology, for which it is necessary to estimate the subject＇s center of gravity from the contact positions and forces with the robot＇s two arms. In this paper, we estimate the center of gravity of object based on the contact point and the contact force estimated by force sensor on both robot arms. The position of gravity center is important to realize care tasks stably. We performed experiments and simulations for the single point contact and dual points contact cases using a cylindrical object. As a result, it is found that although some errors were recognized in the experiments compared with the simulations, the relations between the contact positions and such errors were observed. Such experimental error mainly comes from the difference of shape between the real robot and the model of the robot in simulation.
基金supported by the High Technology Research and Development Programme of China(No.2004AA421030)
文摘A novel 5-DOF exoskeletal rehabilitation robot for upper limbs of hemiplegic patients caused by stroke is proposed in this paper. Its hardware structure is introduced and the control methods are ana- lyzed. To implement intelligent and interactive rehabilitation exercises, motion intention of patients＇ up- per limb is introduced into control methods of rehabilitation exercises. In passive motions, according to the character of unilateral impaired, multi-channels surface electromyogram （sEMG） signals of patients＇ healthy arm muscles are acquired and analyzed to recognize the upper limb motions, then drive the robot and assist paralysis ann＇s rehabilitation exercises. In active-resistant motions, because patients are re- covered with some muscle forces and active motion ability after a rehabilitation period, the terminal force loaded on the robot by an impaired arm are estimated with multi-channel joint torque sensors, according to which, the terminal velocity of the robot is controlled to drive the joint motions with a damp controller.
