Monitoring robot sensor consistency
AssigneeRethink Robotics, Inc.
InventorsMatthew Murray Williamson, Michael Sussman, Waleed A. Farahat
Life of this patent
Estimating the term…
Abstract
Sensors associated with a robot or sub-system thereof (e.g., a series elastic actuator associated with a robot joint) may be monitored for mutual consistency using one or more constraints that relate physical quantities measured by the sensors to each other. The constraints may be based on a physical model of the robot or sub-system.
Claims30
For a robot comprising (i) a series elastic actuator comprising a motor, a gearbox, and a series spring connected to a load and, associated therewith, (ii) a plurality of sensors for monitoring a state or action of the robot by measuring a plurality of respective physical quantities, a method of monitoring the robot for sensor failure, the method comprising:
- establishing at least one constraint relating readings of the plurality of sensors to each other, the at least one constraints including at least one of a kinematics constraint associated with the motor and the series spring, a torque-generation constraint associated with torque generated by the motor and a position of the load, a voltage-velocity constraint associated with current into the motor and angular velocity generated by the motor, a thermal-response constraint associated with a temperature of the motor and a power delivered thereto, or a load-dynamics constraint associated with the angular position of the load and the torque applied to the load;
- and
- monitoring the plurality of sensor readings for violation of the at least one constraint.
A robot comprising:
- a series elastic actuator comprising a motor, a gearbox, and a series spring connected to a load;
- a plurality of sensors measuring a plurality of respective physical quantities associated with the series elastic actuator to thereby monitor a state or action of the robot;
- and
- a computational facility monitoring the robot for sensor failure by monitoring the plurality of sensor readings for violation of at least one constraint relating readings of the plurality of sensors to each other, the at least one constraint comprising at least one of a kinematics constraint associated with the motor and the series spring, a torque-generation constraint associated with torque generated by the motor and a position of the load, a voltage-velocity constraint associated with current into the motor and angular velocity generated by the motor, a thermal-response constraint associated with a temperature of the motor and a power delivered thereto, or a load-dynamics constraint associated with the angular position of the load and the torque applied to the load.
A controller for monitoring a plurality of sensors measuring physical quantities associated with a series elastic actuator comprising a motor, a gearbox, and a series spring connected to a load, the controller comprising:
- signal input ports for receiving readings from the plurality of sensors;
- a memory storing at least one constraint relating the readings of the plurality of sensors to each other, the at least one stored constraint comprising at least one of a kinematics constraint associated with the motor and the series spring, a torque-generation constraint associated with torque generated by the motor and a position of the load, or a voltage-velocity constraint associated with current into the motor and angular velocity generated by the motor;
- and
- a processor for monitoring the plurality of sensor readings for violation of the at least one stored constraint.
Dependencies are inferred from the claim text.