Abstract: An example implementation includes (i) receiving sensor data that indicates topographical features of an environment in which a robotic device is operating, (ii) processing the sensor data into a topographical map that includes a two-dimensional matrix of discrete cells, the discrete cells indicating sample heights of respective portions of the environment, (iii) determining, for a first foot of the robotic device, a first step path extending from a first lift-off location to a first touch-down location, (iv) identifying, within the topographical map, a first scan patch of cells that encompass the first step path, (v) determining a first high point among the first scan patch of cells; and (vi) during the first step, directing the robotic device to lift the first foot to a first swing height that is higher than the determined first high point.

Abstract: Example methods and devices for touch-down detection for a robotic device are described herein. In an example embodiment, a computing system may receive a force signal due to a force experienced at a limb of a robotic device. The system may receive an output signal from a sensor of the end component of the limb. Responsive to the received signals, the system may determine whether the force signal satisfies a first threshold and determine whether the output signal satisfies a second threshold. Based on at least one of the force signal satisfying the first threshold or the output signal satisfying the second threshold, the system of the robotic device may provide a touch-down output indicating touch-down of the end component of the limb with a portion of an environment.

Abstract: An example method may include i) determining a first distance between a pair of feet of a robot at a first time, where the pair of feet is in contact with a ground surface; ii) determining a second distance between the pair of feet of the robot at a second time, where the pair of feet remains in contact with the ground surface from the first time to the second time; iii) comparing a difference between the determined first and second distances to a threshold difference; iv) determining that the difference between determined first and second distances exceeds the threshold difference; and v) based on the determination that the difference between the determined first and second distances exceeds the threshold difference, causing the robot to react.

Abstract: An example implementation involves receiving measurements from an inertial sensor coupled to the robot and detecting an occurrence of a foot of the legged robot making contact with a surface. The implementation also involves reducing a gain value of an amplifier from a nominal value to a reduced value upon detecting the occurrence. The amplifier receives the measurements from the inertial sensor and provides a modulated output based on the gain value. The implementation further involves increasing the gain value from the reduced value to the nominal value over a predetermined duration of time after detecting the occurrence. The gain value is increased according to a profile indicative of a manner in which to increase the gain value of the predetermined duration of time. The implementation also involves controlling at least one actuator of the legged robot based on the modulated output during the predetermined duration of time.

Abstract: Example methods and devices for touch-down detection for a robotic device are described herein. In an example embodiment, a computing system may receive a force signal due to a force experienced at a limb of a robotic device. The system may receive an output signal from a sensor of the end component of the limb. Responsive to the received signals, the system may determine whether the force signal satisfies a first threshold and determine whether the output signal satisfies a second threshold. Based on at least one of the force signal satisfying the first threshold or the output signal satisfying the second threshold, the system of the robotic device may provide a touch-down output indicating touch-down of the end component of the limb with a portion of an environment.

Abstract: An example implementation includes (i) receiving sensor data that indicates topographical features of an environment in which a robotic device is operating, (ii) processing the sensor data into a topographical map that includes a two-dimensional matrix of discrete cells, the discrete cells indicating sample heights of respective portions of the environment, (iii) determining, for a first foot of the robotic device, a first step path extending from a first lift-off location to a first touch-down location, (iv) identifying, within the topographical map, a first scan patch of cells that encompass the first step path, (v) determining a first high point among the first scan patch of cells; and (vi) during the first step, directing the robotic device to lift the first foot to a first swing height that is higher than the determined first high point.

Abstract: An example implementation involves receiving measurements from an inertial sensor coupled to the robot and detecting an occurrence of a foot of the legged robot making contact with a surface. The implementation also involves reducing a gain value of an amplifier from a nominal value to a reduced value upon detecting the occurrence. The amplifier receives the measurements from the inertial sensor and provides a modulated output based on the gain value. The implementation further involves increasing the gain value from the reduced value to the nominal value over a predetermined duration of time after detecting the occurrence. The gain value is increased according to a profile indicative of a manner in which to increase the gain value of the predetermined duration of time. The implementation also involves controlling at least one actuator of the legged robot based on the modulated output during the predetermined duration of time.

Abstract: An example method may include i) determining a first distance between a pair of feet of a robot at a first time, where the pair of feet is in contact with a ground surface; ii) determining a second distance between the pair of feet of the robot at a second time, where the pair of feet remains in contact with the ground surface from the first time to the second time; iii) comparing a difference between the determined first and second distances to a threshold difference; iv) determining that the difference between determined first and second distances exceeds the threshold difference; and v) based on the determination that the difference between the determined first and second distances exceeds the threshold difference, causing the robot to react.

Abstract: An example method may include i) detecting a disturbance to a gait of a robot, where the gait includes a swing state and a step down state, the swing state including a target swing trajectory for a foot of the robot, and where the target swing trajectory includes a beginning and an end; and ii) based on the detected disturbance, causing the foot of the robot to enter the step down state before the foot reaches the end of the target swing trajectory.

Abstract: An example method may include i) detecting a disturbance to a gait of a robot, where the gait includes a swing state and a step down state, the swing state including a target swing trajectory for a foot of the robot, and where the target swing trajectory includes a beginning and an end; and ii) based on the detected disturbance, causing the foot of the robot to enter the step down state before the foot reaches the end of the target swing trajectory.

Abstract: In some applications, a piston of a hydraulic actuator may move at high speeds, and large undesired forces may be generated if the piston reaches an end-stop of the hydraulic actuator at a high speed. The undesired forces may, for example, cause mechanical damage in the hydraulic actuator. A controller may receive information indicative of the piston reaching a first position at a first threshold distance from the end-stop, and, in response, may modify a signal to a valve assembly controlling flow of hydraulic fluid to and from the hydraulic actuator. Further, the controller may receive information indicative of the piston reaching a second position at a second threshold distance closer to the end-stop of the hydraulic actuator, and, in response, the controller may further modify the signal to the valve assembly so as to apply a force on the piston in a away from the end-stop.

Abstract: A robot includes an inverted pendulum body having first and second end portions, a counter-balance body disposed on the inverted pendulum body and configured to move relative to the inverted pendulum body, at least one leg having first and second ends, and a drive wheel rotatably coupled to the second end of the at least one leg. The first end of the at least one leg is prismatically coupled to the second end portion of the inverted pendulum body.

Abstract: A method for palletizing includes receiving a target box location for a box grasped by the end-effector, the box having a top surface, a bottom surface, and side surfaces. The method also includes positioning the box at an initial position adjacent to the target box location and tilting the box at an angle relative to a ground plane where the angle is formed between the ground plane and the bottom surface. The method further includes shifting the box from the initial position in a first direction to a first alignment position that satisfies a threshold first alignment distance, shifting the box from the first alignment position in a second direction to the target box location that satisfies a threshold second alignment distance, and releasing the box from the end-effector. The release of the box causes the box to pivot toward a boundary edge of the target box location.

Abstract: A method for a multi-body controller receives steering commands for a robot to perform a given task. The robot includes an inverted pendulum body, a plurality of joints, an arm coupled to the inverted pendulum body, a leg coupled to the inverted pendulum body, and a drive wheel rotatably coupled to the leg. With the steering commands, the method generates a wheel torque and a wheel axle force to perform the given task. The method includes receiving movement constraints for the robot and manipulation inputs configured to manipulate the arm to perform the given task. For each joint, the method generates a corresponding joint torque having an angular momentum where the joint torque satisfies the movement constraints based on the manipulation inputs, the wheel torque, and the wheel axle force. The method further includes controlling the robot to perform the given task using the joint torques.

Abstract: A method of operating a robot includes driving a robot to approach a reach point, extending a manipulator arm forward of the reach point, and maintaining a drive wheel and a center of mass of the robot rearward of the reach point by moving a counter-balance body relative to an inverted pendulum body while extending the manipulator arm forward of the reach point. The robot includes the inverted pendulum body, the counter-balance body deposed on the inverted pendulum body, the manipulator arm connected to the inverted pendulum body, at least one leg having a first end prismatically coupled to the inverted pendulum body, and the drive wheel rotatably coupled to a second end of the at least one leg.

Abstract: An example method may include i) detecting a disturbance to a gait of a robot, where the gait includes a swing state and a step down state, the swing state including a target swing trajectory for a foot of the robot, and where the target swing trajectory includes a beginning and an end; and ii) based on the detected disturbance, causing the foot of the robot to enter the step down state before the foot reaches the end of the target swing trajectory.

Abstract: An example implementation includes (i) receiving sensor data that indicates topographical features of an environment in which a robotic device is operating, (ii) processing the sensor data into a topographical map that includes a two-dimensional matrix of discrete cells, the discrete cells indicating sample heights of respective portions of the environment, (iii) determining, for a first foot of the robotic device, a first step path extending from a first lift-off location to a first touch-down location, (iv) identifying, within the topographical map, a first scan patch of cells that encompass the first step path, (v) determining a first high point among the first scan patch of cells; and (vi) during the first step, directing the robotic device to lift the first foot to a first swing height that is higher than the determined first high point.

Abstract: An example implementation involves receiving measurements from an inertial sensor coupled to the robot and detecting an occurrence of a foot of the legged robot making contact with a surface. The implementation also involves reducing a gain value of an amplifier from a nominal value to a reduced value upon detecting the occurrence. The amplifier receives the measurements from the inertial sensor and provides a modulated output based on the gain value. The implementation further involves increasing the gain value from the reduced value to the nominal value over a predetermined duration of time after detecting the occurrence. The gain value is increased according to a profile indicative of a manner in which to increase the gain value of the predetermined duration of time. The implementation also involves controlling at least one actuator of the legged robot based on the modulated output during the predetermined duration of time.

Abstract: An example method may include i) detecting a disturbance to a gait of a robot, where the gait includes a swing state and a step down state, the swing state including a target swing trajectory for a foot of the robot, and where the target swing trajectory includes a beginning and an end; and ii) based on the detected disturbance, causing the foot of the robot to enter the step down state before the foot reaches the end of the target swing trajectory.

Abstract: An example implementation involves receiving measurements from an inertial sensor coupled to the robot and detecting an occurrence of a foot of the legged robot making contact with a surface. The implementation also involves reducing a gain value of an amplifier from a nominal value to a reduced value upon detecting the occurrence. The amplifier receives the measurements from the inertial sensor and provides a modulated output based on the gain value. The implementation further involves increasing the gain value from the reduced value to the nominal value over a predetermined duration of time after detecting the occurrence. The gain value is increased according to a profile indicative of a manner in which to increase the gain value of the predetermined duration of time. The implementation also involves controlling at least one actuator of the legged robot based on the modulated output during the predetermined duration of time.