Motion target generating apparatus of mobile robot

Patent metadata

Field	Value
Publication number	US-9481083-B2
Application number	US-201514797311-A
Country	US
Kind code	B2
Filing date	Jul 13, 2015
Priority date	Jul 16, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A motion target generating apparatus calculates the time series of motion accelerations of a base body 2 and the distal end portion of each of movable links 3 and 4 of a robot 1 at a plurality of times after a current time such that the value of a predetermined evaluation function is minimized in a range in which a joint motion constraint condition of each of the movable links 3 and 4 of the robot 1 is satisfied. Based on the calculated values of the motion accelerations at an initial time, new desired motion accelerations of the base body 2 and the distal end portion of each of the movable links 3 and 4 are determined. The desired value for controlling each joint of the robot 1 is determined on the basis of the desired motion accelerations.

First claim

What is claimed is:

1. A motion target generating apparatus of a mobile robot adapted to sequentially generate, at a predetermined control processing cycle, a desired control value for controlling a motion of each joint of a mobile robot, which has a plurality of movable links, including a leg link extended from a base body, and in which a distal end portion of each of the movable links is configured to move relative to the base body by a motion of a joint provided in the movable link between the distal end portion and the base body, the motion target generating apparatus comprising:
estimated movable link distal end portion trajectory setting element that sets an estimated movable link distal end portion trajectory, which is an estimated trajectory of a desired value of a motion state of the distal end portion of each of the movable links after a current time, at each control processing cycle;
estimated overall momentum trajectory setting element that sets an estimated overall momentum trajectory, which is an estimated trajectory of a desired value of an overall momentum of the mobile robot after the current time, at each control processing cycle;
estimated overall motion state trajectory setting element that temporarily determines, at each control processing cycle, an estimated overall motion state trajectory, which is an estimated trajectory of a desired value of an overall motion state of the mobile robot after the current time, such that the set estimated movable link distal end portion trajectory and the set estimated overall momentum trajectory can be attained;
motion acceleration determining element that, at each control processing cycle, carries out arithmetic processing of a solution technique of a secondary plan problem by using a joint motion constraint condition, which is a predetermined constraint condition, which is related to the motion state of each joint of each of the movable links and which is not used in the processing by the estimated overall motion state trajectory determining element, and a predetermined evaluation function related to a predetermined type of state amount of the mobile robot at a plurality of times after the current time so as to calculate motion accelerations of the base body and the distal end portion of each of the movable links at the plurality of times such that a value of the predetermined evaluation function is minimized within a range that satisfies the joint motion constraint condition, thereby determining new desired motion accelerations of the base body and the distal end portion of each of the movable links based on calculated values of the motion accelerations of the base body and the distal end portion of each of the movable links at an initial time among the plurality of times; and
desired joint control value determining element that determines a desired control value of each joint of the mobile robot at each control processing cycle such that the determined desired motion accelerations are attained,
wherein the predetermined evaluation function is an evaluation function configured such that the value thereof changes according to the degree of agreement between a time series of the predetermined type of state amount at the plurality of times calculated using motion velocities of the base body and the distal end portion of each of the movable links defined by the calculated values of the motion accelerations at the plurality of times and a Jacobian matrix defined by the estimated overall motion state trajectory and a time series of the predetermined type of state amount at the plurality of times defined by the estimated overall motion state trajectory,
the joint motion constraint condition is a constraint condition expressed by an inequality that defines a variable range of the motion state of each joint of each of the movable links calculated using the motion velocities of the base body and the distal end portion of each of the movable links defined by the calculated values of the motion accelerations at the plurality of times and the Jacobian matrix defined by the estimated overall motion state trajectory, and
each control processing cycle includes a series of arithmetic processing carried out by the estimated movable link distal end portion trajectory setting element, the estimated overall momentum trajectory setting element, the estimated overall motion state trajectory setting element, the motion acceleration determining element, and the desired joint control value determining element.

2. The motion target generating apparatus of a mobile robot according to claim 1 ,
wherein the predetermined type of state amount includes at least the overall momentum of the mobile robot, and
the predetermined evaluation function is configured such that the value thereof changes according to a momentum evaluation index value indicative of a degree of agreement between a time series of the overall momentum of the mobile robot at the plurality of times calculated using the motion velocities of the base body and the distal end portion of each of the movable links, which are defined by the calculated values of the motion accelerations at the plurality of times, and a Jacobian matrix defined by the estimated overall motion state trajectory, and a time series of a desired value of the momentum at the plurality of times defined by the estimated overall momentum trajectory.

3. The motion target generating apparatus of a mobile robot according to claim 2 ,
wherein the predetermined type of state amount further includes motion accelerations of the base body and the distal end portion of each of the movable links, and
the predetermined evaluation function is configured such that the value thereof changes according to a motion acceleration evaluation index value indicative of a degree of agreement between a time series of the calculated values of the motion accelerations of the base body and the distal end portion of each of the movable links at the plurality of times and a time series of the motion accelerations at the plurality of times defined by the estimated overall motion state trajectory, and the momentum evaluation index value.

4. The motion target generating apparatus of a mobile robot according to claim 2 ,
wherein the estimated overall momentum trajectory setting element includes element that sets an estimated trajectory of a desired ZMP of the mobile robot after the current time, and
the overall momentum of the mobile robot that constitutes the predetermined type of state amount includes an angular momentum about a desired ZMP of the mobile robot.

5. The motion target generating apparatus of a mobile robot according to claim 3 ,
wherein the estimated overall momentum trajectory setting element includes element that sets an estimated trajectory of a desired ZMP of the mobile robot after the current time, and
the overall momentum of the mobile robot that constitutes the predetermined type of state amount includes an angular momentum about a desired ZMP of the mobile robot.

Assignees

• Honda Motor Co Ltd

Inventors

• Kanazawa Masao
• Watabe Tomoki
• Kamioka Takumi
• Asatani Minami

Classifications

• B25J9/1607 Primary

  Calculation of inertia, jacobian matrixes and inverses · CPC title

• Y10S901/46

  Sensing device · CPC title

• Y10S901/28

  Joint · CPC title

• Y10S901/01

  Mobile robot · CPC title