Force reflecting hand controller

• US 5,193,963 A
• Filed: 10/31/1990
• Issued: 03/16/1993
• Est. Priority Date: 10/31/1990
• Status: Expired due to Fees

• Current Assignee: Department of Health and Human Services (State of Victoria)
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Townsend, William T., Snow, Edward R., McAffee, Douglas A.
• Primary Examiner(s): Huppert, Michael S.
• Assistant Examiner(s): Underwood, Donald W.
• Application Number:
  US07/608,658
• Time in Patent Office: 867 Days
• Field of Search: 414/5, 414/7, 414/222
• US Class Current: 414/5
• CPC Class Codes: B25J 13/025 comprising haptic means
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02

Abstract

A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator'"'"'s range of motion than previous designs.

Claims

1. A universal hand controller device for interfacing a human operator with a slave machine such as a robot comprising:

a base;

a plurality of serially connected mechanical links extending from the base, the mechanical links being arranged into a first group of first, second, and third linear position links and a second group of first, second, and third angular position links;

a handgrip connected to the serially connected mechanical links distal from the base such that a human operator may grasp the handgrip and control the position of the handgrip relative to the base through the serially connected mechanical links;

a plurality of rotary joints arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base, there being one rotary joint corresponding to each degree of freedom, each rotary joint having a drive mechanism comprising a drive motor, a drive pulley assembly and a drive cable connected between the drive motor and the drive pulley assembly such that each joint is cable driven;

means for mounting the drive motors for driving the rotary joints corresponding to the rotational degrees of freedom to one of the linear position links such that the drive cables in the drive mechanisms for the rotary joints corresponding to the rotational degrees of freedom pass through at least one rotary joint corresponding to the linear position link upon which the drive motors for driving the rotary joints are mounted; and

means for guiding the drive cable for the first, second, and third angular position links parallel to an axis of rotation of a third of the rotary joints.

2. The universal hand controller device of claim 1 additionally comprising means for guiding the drive cable for the second and third angular position links along an axis of rotation of a fourth of the rotary joints.

3. The universal hand controller device of claim 2 additionally comprising means for guiding the drive cable for the third angular position link along an axis of rotation of a fifth of the rotary joints, wherein the drive mechanism for each rotary joint is kinematically decoupled from all of the other rotary joints such that motion of the handgrip about any selected joint causes no motion of the handgrip relative to any of the other joints.

4. The universal hand controller device of claim 3 wherein rotation of the third linear position link about the third joint causes a uniform twist in the cables for the fourth, fifth, and a sixth of the joints.

5. The universal hand controller device of claim 4 wherein the motors for driving the third, fourth, fifth, and sixth joints are remotely located from the corresponding rotary joints and wherein the drive cables for each rotary joint have constant length as rotation occurs about any of the rotary joints.

6. A universal hand controller device for interfacing a human operator with a slave machine such as a robot, comprising:

a base;

a plurality of serially connected mechanical links extending from the base, the mechanical links being arranged into a first group of linear position links and a second group of angular position links;

a handgrip connected to the third angular position link distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the serially connected mechanical links;

a plurality of rotary joints arranged to connect the mechanical links together to provide three translational degrees of freedom and three rotational degrees of freedom of motion of the handgrip relative to the base, there being one rotary joint corresponding to each degree of freedom, each rotary joint having a drive mechanism comprising a corresponding a motor, a drive pulley assembly, and a drive cable connected between the motor and drive pulley assembly such that each joint is cable driven;

the mechanical links and rotary joints including

a first linear position link rotatably mounted to the base by a first one of the plurality of rotary joints;

a second linear position link rotatably mounted to the first linear position link by a second one of the plurality of rotary joints;

a third linear position link rotatably mounted to the second linear position link by a third one of the plurality of rotary joints;

a first angular position link rotatably mounted to the third linear position link by a fourth one of the plurality of rotary joints;

a second angular position link rotatably mounted to the first angular position link by a fifth one of the plurality of rotary joints;

a third angular position link rotatably mounted to the second angular position link by a sixth one of the plurality of rotary joints, the first, second, and third angular position links being arranged to have axes of rotation that intersect at a point that is fixed with respect to the third linear position link; and

means for mounting the drive motors for driving the fourth, fifth, and sixth rotary joints to the third linear position link such that the drive cables in the drive mechanisms for the fourth, fifth, and sixth rotary joints pass through the axis of rotation of the third rotary joint;

wherein the drive cable for the first, second, and third angular position links are parallel to the axis of rotation of the third rotary joint, the drive cable for the second and third angular position links are guided along the axis of rotation of the fourth rotary joint, and the drive cable for the third angular position link is guided along the axis of rotation of the fifth rotary joint, so that the drive mechanism for each rotary joint is kinematically decoupled from all of the other rotary joints such that motion of the handgrip about any selected joint causes no motion of the handgrip relative to any of the other joints.