# US 11,298,823 B2 · Sensor device and sensing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,823 B2 - Document ID: US11298823B2 - Status: Granted - Kind: B2 - Application number: 16/763,547 - Filed: 2018-08-24 - Published: 2020-11-19 - Granted: 2022-04-12 - Earliest claimed: 2017-11-21 - Assignees: Sony Corporation - Applicants: Sony Corporation - Inventors: Toshimitsu Kai - Web page: https://patentgrep.com/patent/US11298823B2 ## CPC - B25J 9/1633: {compliant, force, torque control, e.g. combined with position control} - B25J 9/1674: {characterised by safety, monitoring, diagnostic} - B25J 13/085: {Force or torque sensors (B25J13/082, B25J13/084 take precedence)} - H02P 6/28: Arrangements for controlling current (H02P6/10 takes precedence) - H02P 29/00: Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors (arrangements for starting electric motors H02P1/00; arrangements for stopping or slowing electric motors H02P3/00; control of motors that can be connected to two or more different electric power supplies H02P4/00; regulating or controlling the speed or torque of two or more electric motors H02P5/00; vector control H02P21/00) - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A sensor device and a sensing method capable of detecting even a small external force are provided. A sensor device includes: a backflow prevention unit provided in the middle of a circuit that supplies a current from a power supply unit to a motor unit; a potential detection unit configured to detect each of potentials at a preceding stage and a subsequent stage of the backflow prevention unit; and an external force detection unit configured to detect an external force applied to a member connected to the motor unit on the basis of the potentials at the preceding stage and the subsequent stage of the backflow prevention unit. ## Claims ### Claim 1 A sensor device, comprising: a backflow prevention unit provided in a middle of a circuit that supplies a current from a power supply unit to a motor unit; a potential detection unit configured to detect a potential at a preceding stage and a potential at a subsequent stage of the backflow prevention unit; and an external force detection unit configured to detect an external force applied to a member connected to the motor unit on a basis of the potential at the preceding stage and the potential at the subsequent stage of the backflow prevention unit. ### Claim 2 (depends on 1) The sensor device according to claim 1, wherein the external force detection unit detects the external force by comparing the potential at the preceding stage of the backflow prevention unit with the potential at the subsequent stage of the backflow prevention unit. ### Claim 3 (depends on 2) The sensor device according to claim 2, wherein the external force detection unit detects the external force in a case where the potential at the subsequent stage of the backflow prevention unit is higher than the potential at the preceding stage of the backflow prevention unit by a threshold or more. ### Claim 4 (depends on 1) The sensor device according to claim 1, wherein the backflow prevention unit prevents a current from flowing from the motor unit to the power supply unit. ### Claim 5 (depends on 4) The sensor device according to claim 4, wherein the current flowing from the motor unit to the power supply unit is generated by a back electromotive force in the motor unit caused by the external force. ### Claim 6 (depends on 4) The sensor device according to claim 4, wherein the backflow prevention unit is provided so as to be able to control whether or not to prevent the current from flowing from the motor unit to the power supply unit. ### Claim 7 (depends on 6) The sensor device according to claim 6, wherein in a case where the external force is detected by the external force detection unit, the backflow prevention unit permits the current to flow from the motor unit to the power supply unit. ### Claim 8 (depends on 1) The sensor device according to claim 1, wherein the external force detection unit further calculates an increasing speed of the potential at the subsequent stage of the backflow prevention unit, and calculates a magnitude of the external force on a basis of the increasing speed and an output torque of the motor unit. ### Claim 9 (depends on 1) The sensor device according to claim 1, wherein rotation of the motor unit is controlled by torque control. ### Claim 10 (depends on 1) The sensor device according to claim 1, wherein the motor unit includes a three-phase alternating-current motor. ### Claim 11 (depends on 10) The sensor device according to claim 10, wherein an inverter circuit is further provided in the middle of the circuit that supplies the current from the power supply unit to the three-phase alternating-current motor, and the backflow prevention unit is provided at a preceding stage of the inverter circuit. ### Claim 12 (depends on 1) The sensor device according to claim 1, wherein the power supply unit includes a direct-current power supply. ### Claim 13 (depends on 1) The sensor device according to claim 1, wherein the power supply unit includes at least either of a battery or a capacitor. ### Claim 14 (depends on 1) The sensor device according to claim 1, wherein the motor unit rotates a joint of a robotic device. ### Claim 15 (depends on 14) The sensor device according to claim 14, wherein the joint is provided to an arm portion or a leg portion of the robotic device. ### Claim 16 A sensing method comprising: detecting a potential at a preceding stage and a potential at a subsequent stage of a backflow prevention unit provided in a middle of a circuit that supplies a current from a power supply unit to a motor unit; and detecting an external force applied to a member connected to the motor unit on a basis of the potential at the preceding stage and the potential at the subsequent stage of the backflow prevention unit.