A jointed mechanism includes a passive pendulum system attached to and suspended from the multi-axis robot. The system includes one or more position sensors configured to measure a joint angle on the pendulum system, at least one arm, and an end-effector attached to a distal end of the pendulum system. A controller implements a method to selectively control motion of the robot in a plurality of control modes. The control modes include a Cooperative Mode and an Autonomous Mode. The controller is configured to detect contact with the end-effector when operating in the Autonomous Mode, and to automatically initiate a control action in response to the contact. The pendulum system may be a parallelogram arrangement.

A robotic system for use with a payload includes a robot, a passive compliance mechanism, position sensors, and an electronic control unit (ECU). Actuated joints of the robot provide the robotic system with actuated degrees of freedom (DOF). The compliance mechanism is connected to the robot and payload, and has unactuated joints providing the robotic system with unactuated DOF. The sensors measure joint positions of the joints. The ECU has a trajectory generator block which generates a payload trajectory signal in response to dynamic control inputs, and an impedance control unit (ICU) applying damping and stiffness parameters to the payload trajectory signal to generate an initial velocity command. A stiction compensation block allows the robotic system to generate a velocity offset, and applies the velocity offset to the initial velocity command to produce a final velocity command for the robot.

A jointed mechanism includes a passive pendulum system attached to and suspended from the multi-axis robot. The system includes one or more position sensors configured to measure a joint angle on the pendulum system, at least one arm, and an end-effector attached to a distal end of the pendulum system. A controller implements a method to selectively control motion of the robot in a plurality of control modes. The control modes include a Cooperative Mode and an Autonomous Mode. The controller is configured to detect contact with the end-effector when operating in the Autonomous Mode, and to automatically initiate a control action in response to the contact. The pendulum system may be a parallelogram arrangement.

A robotic system includes a jointed mechanism, position sensors, and a controller. The mechanism has an end-effector, and further includes actively-controlled joints and passive joints that are redundant with the actively-controlled joints. The position sensors are operable for measuring joint positions of the passive joints. The controller is in communication with the position sensors, and is programmed to execute a method to selectively control the actively-controlled joints in response to the measured joint positions using force control and/or a modeled impedance of the robotic mechanism. Possible control modes in impedance control include an Autonomous Mode in which an operator does not physically interact with the end-effector and a Cooperative Control Mode in which the operator physically interacts with the end-effector.

A robotic system for use with a payload includes a robot, a passive compliance mechanism, position sensors, and an electronic control unit (ECU). Actuated joints of the robot provide the robotic system with actuated degrees of freedom (DOF). The compliance mechanism is connected to the robot and payload, and has unactuated joints providing the robotic system with unactuated DOF. The sensors measure joint positions of the joints. The ECU has a trajectory generator block which generates a payload trajectory signal in response to dynamic control inputs, and an impedance control unit (ICU) applying damping and stiffness parameters to the payload trajectory signal to generate an initial velocity command. A stiction compensation block allows the robotic system to generate a velocity offset, and applies the velocity offset to the initial velocity command to produce a final velocity command for the robot.

A robotic system includes a jointed mechanism, position sensors, and a controller. The mechanism has an end-effector, and further includes actively-controlled joints and passive joints that are redundant with the actively-controlled joints. The position sensors are operable for measuring joint positions of the passive joints. The controller is in communication with the position sensors, and is programmed to execute a method to selectively control the actively-controlled joints in response to the measured joint positions using force control and/or a modeled impedance of the robotic mechanism. Possible control modes in impedance control include an Autonomous Mode in which an operator does not physically interact with the end-effector and a Cooperative Control Mode in which the operator physically interacts with the end-effector.