Robotic device
AssigneeDyson Technology Limited
InventorEdoardo Farnioli
Life of this patent
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Abstract
Certain examples described herein provide a method of controlling a robotic device including a body, an end effector coupled to the body by one or more joints and a propulsion system to drive the one or more joints to control a state of the robotic device. Example methods include applying impedance control to the robotic device; determining a reference trajectory of the end effector; detecting an applied external force and/or torque acting on the robotic device causing a departure from the reference trajectory; calculating an adjustment to be applied to one or more of the one or more joints to compensate for the detected applied external force and/or torque; and using the calculated adjustment to control the one or more joints to actuate the end effector and recover the reference trajectory of the end effector.
Claims19
A method of controlling a robotic device comprising a body, an end effector coupled to the body by one or more joints and a propulsion system to drive the one or more joints to control a state of the robotic device, the method comprising:
- applying impedance control to the robotic device;
- determining a reference trajectory of the end effector;
- detecting an applied external force and/or torque on the robotic device causing a departure from the reference trajectory, wherein the applied external force or torque is at least partially due to a weight of a load carried by the end effector;
- calculating an adjustment to be applied to one or more of the one or more joints to compensate for the detected applied external force and/or torque;
- applying a low pass filter to a signal related to the detected applied external force and/or torque, the low pass filter providing a control delay to improve performance of the impedance control;
- and
- using the calculated adjustment to control the one or more joints to actuate the end effector and recover the reference trajectory of the end effector, wherein the adjustment is a joint force and torque to be applied to the one or more joints, the adjustment is dynamically adjusted in real time based on the estimated joint force and/or torque and the control delay provided by the low pass filter,
- wherein the reference trajectory defines a trajectory for the robotic device to lay the load on a surface, the method comprises refining the adjustment to maintain the reference trajectory as the load is laid on the surface and the weight of the load acting on the end effector is reduced, the adjustment is reduced to zero as the load is laid down on the surface such that the end effector releases the load when the detected applied external force or torque, due to the weight of the load, is zero.
A robotic device, comprising:
- a body;
- an end effector coupled to the body by one or more joints;
- a propulsion system to drive the one or more joints to control a state of the robotic device;
- and
- a controller configured to:
- apply impedance control to the robotic device;
- determine a reference trajectory of the end effector;
- detect an applied external force and/or torque on the robotic device causing a departure from the reference trajectory, wherein the applied external force or torque is due to a weight of a load carried by the end effector;
- calculate an adjustment to be applied to one or more of the one or more joints to compensate for the detected applied external force and/or torque;
- apply a low pass filter to a signal related to the detected applied external force and/or torque, the low pass filter providing a control delay to improve performance of the impedance control;
- and
- using the calculated adjustment, to control the one or more joints to actuate the end effector and recover the reference trajectory of the end effector, wherein the adjustment is a joint force and torque to be applied to the one or more joints, the adjustment is dynamically adjusted in real time based on the estimated joint force and/or torque and the control delay provided by the low pass filter,
- wherein the reference trajectory defines a trajectory for the robotic device to lay the load on a surface, the adjustment is refined to maintain the reference trajectory as the load is laid on the surface and the weight of the load acting on the end effector is reduced, the adjustment is reduced to zero as the load is laid down on the surface such that the end effector releases the load when the detected applied external force or torque, due to the weight of the load, is zero.
Dependencies are inferred from the claim text.