ROBOT WITH AN INVERSE KINEMATICS (IK)-BASED CONTROLLER FOR RETARGETING INPUT MOTIONS

Number: 20220226987
Published: 2022-07-21
Filed: 2021-04-06
Assignee: Disney Enterprises, Inc.
Inventors: Bacher; Moritz Niklaus, Knoop; Lars Espen, Hopkins; Michael Anthony, Cesare; Kyle Michael, Schumacher; Christian Gabriel, Coros; Stelian
CPC: B62D57/032; B25J9/1607; B25J13/088; B25J9/1623
Verdict: High Hardware
Source: Google Patents · FreePatentsOnline

The keeper's note

Robot IK-based motion-retargeting controller (Bächer, bipedal-adjacent).

Abstract

A new controller for use in robots with kinematic loops as well as in most other types of robots (such as those with fully actuated kinematic trees). The controller includes an inverse kinematics (IK) module that implements a versatile IK formulation for retargeting of motions, including expressive motions, onto mechanical systems (i.e., robots with loops and/or without loops). Further, the controller is configured to support the precise control of the position and orientation of end effectors and the center of mass (CoM) (such as of walking robots). The formulation of the algorithms carried out by the IK module safeguards against a disassembly when IK targets are moved outside the workspace of the robot. A regularizer is included in the controller that smoothly circumvents kinematic singularities where velocities go to infinity.

Background

BACKGROUND 1. Field of the Description

The present description relates, in general, to robots (which may include nearly all types of robot designs or robotic systems) and associated control systems (or “controllers”) for such robots, and, more particularly, to a controller (and a robot making use of such a controller) that is configured to make use of a versatile inverse kinematics (IK) formulation for retargeting input motions onto a robot via the controller's output (or control signals). The IK-based controller may be particularly well-suited for use with robots with kinematic loops but is useful with most other types of robots as well. 2. Relevant Background

There is an ongoing demand for improved controllers and control processes for robotic systems or “robots” that allow robot designers and operators to impart desired motions onto the robots. In many cases, it is desirable for the robots to closely simulate the motions of a human or other input motions or animations while retaining balance and other movement criteria. In many cases, retargeting of motions onto a robot can be challenging and be processor intensive or costly, and this is true for many general types of robots but especially true for robots with kinematic loops.

Robots with kinematic loops have several advantages over designs that are made up of a fully actuated kinematic tree. For example, these robots have superior stiffness, allow the placement of actuators where there is space, and,

Claims

1. A robot, comprising: a kinematic structure with mechanical joints, bodies interconnected with the mechanical joints, and at least one actuator for imparting movements to the kinematic structure; and a controller generating control signals to operate the kinematic structure to selectively move the at least one movable body, wherein the controller includes an inverse kinematics (IK) solver, wherein the controller processes input motions with the IK solver by solving inverse kinematics to retarget the input motions onto the kinematic structure with the control signals, and wherein the IK solver solves the inverse kinematics by applying hard constraints to at least one of the mechanical joints or one of the bodies and by applying soft constraints to an IK target associated with a point on the kinematic structure. || 8. A robot, comprising: a mechanical system with one or more movable bodies; and a controller generating control signals causing the mechanical system to move the one or more movable bodies, wherein the controller includes an inverse kinematics (IK) solver, wherein the controller generates the control signals by processing input motions with the IK solver by using inverse kinematics to retarget the input motions on the mechanical system, and wherein the IK solver uses a center of mass (CoM) module defining a trajectory objective for the CoM of the mechanical system to follow while carrying out the retargeted input motions. || 15. A robot, comprising: a kinematic structure with mechanical joints, bodies interconnected with the mechanical joints, and at least one actuator for imparting movements to the kinematic structure; and a controller generating control signals to operate the kinematic structure to selectively move the at least one movable body, wherein the controller includes an inverse kinematics (IK) solver, wherein the controller generates the control signals by processing input motions with the IK solver by solving inverse kinematics to retarget the input motions onto the kinematic structure, and wherein the solving of the inverse kinematics is configured to prevent velocity singularities when the kinematic structure operates based on the control signals to move with the retargeted input motions.