Issued Patents

Methods and apparatuses for selectively controlling motor power boards

US9231503B2

Methods and systems for building arbitrary motor controllers are described. An example motor controller may include multiple motor power boards connected in a stacked configuration and coupled in parallel. Each motor power board may include one or more power transistors and one or more gate drivers having an input terminal coupled to a control signal connector and an output terminal coupled to a gate terminal of the one or more power transistors. The example motor controller may also include a power bus connector coupled, in parallel, to a respective output terminal of each of the multiple motor power boards. Further, the example motor controller may include a control system coupled to the control signal connector and configured to selectively enable a set that includes one or more of the multiple motor power boards based on an output power requirement.


Robotic devices with ambient indications of joint status

US9375841B1

In examples, robotic devices with ambient indications of joint status are provided. An example robotic device includes one or more actuators coupled through one or more joints to form a robotic manipulator, and an indicator co-located in proximity to the one or more joints to provide visual feedback on the robotic manipulator at the one or more joints and about the one or more joints. The visual feedback may include information indicative of an operating status of the one or more joints including an indication of an amount of torque that the one or more joints is experiencing. The robotic device also includes a controller programmable to control the indicator co-located proximal to the one or more joints to provide the visual feedback indicative of the operating status of the one or more joints.


Cogging torque measurement for a robot actuator

US9205556B1

Systems and methods for measuring cogging torque. An example method includes causing an electric motor to rotate in a positive direction, and for given multiple encoder positions of an encoder, determining a first respective motor winding current applied to the electric motor at the given encoder position. Additionally, the method includes causing the electric motor to rotate in a negative direction, and for the given multiple encoder positions, determining a second respective motor winding current applied to the electric motor at the given encoder position. Further, the method includes, for the given multiple encoder positions, determining a respective cogging torque based on a difference between the first and second respective winding currents. And the method includes storing a cogging torque profile for the electric motor in a database based on the determined respective cogging torque for the given multiple encoder positions.


System and method for failure detection of a robot actuator

US9205560B1

Systems and methods for detecting actuator component or sensor failure using non-equivalent sensors are described. An example method includes actuating a robot actuator, and determining a first result and second result of the actuation using a first sensor and second sensor respectively. Additionally, the method includes determining a first estimate of an internal state of the robot actuator using the first result, and determining a second estimate of the internal state using the second result and a normalization function that normalizes the second result for comparison with the first estimate. Further, the method includes determining whether a difference between the first estimate of the internal state and the second estimate of the internal state satisfies an error threshold. And the method includes providing an output indicative of a potential fault of the robot actuator in response to determining that the difference does not satisfy the error threshold.

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