CN111745670A

CN111745670A - Multi-wheel-arm space robot for large rolling target

Info

Publication number: CN111745670A
Application number: CN202010525493.6A
Authority: CN
Inventors: 李常; 杜宝森; 王燕波; 李晓琪; 吕博瀚
Original assignee: Beijing Research Institute of Precise Mechatronic Controls
Current assignee: Beijing Research Institute of Precise Mechatronic Controls
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2020-10-09

Abstract

A multi-wheel-arm space robot for large rolling targets belongs to the technical field of electricity. The multi-wheel arm is composed of a universal mechanical arm and a full-freedom active friction end effector. The three coupled ohmic wheels are driven by three servo motors and are in close contact with the friction ball, so that six-degree-of-freedom omnidirectional control of the friction ball is realized. The friction ball is restrained by the omnidirectional bearing to be contacted with a capture object, and the contact object is controlled by the friction force generated by the contact. The invention solves the problem of passive racemization capture of spinning motion of a non-cooperative target. The end effector is contacted with the surface of a captured object through a friction ball which can be controlled in an omnidirectional manner, and the captured object is captured and controlled through the cooperative control of a plurality of mechanical arms.

Description

Multi-wheel-arm space robot for large rolling target

Technical Field

The invention relates to a multi-wheel-arm space robot for a large rolling target, in particular to a spacecraft space grabbing end effector based on a full-freedom active friction principle of an omnidirectional wheel, and belongs to the technical field of electricity.

Background

Space-operated spacecraft require various on-orbit services. The spacecraft with the failure and the over-age need to clean out the operation orbit in time. On-orbit servicing and cleaning

With the development of aerospace technology, space docking is developed from cooperative target docking to non-cooperative target docking. The non-cooperative target docking technology is utilized to realize docking between any aircrafts in space, and the space activity range is expanded, so that space activities such as space garbage cleaning, satellite recovery, fuel supply, part replacement, system upgrading and the like are realized.

Since the end of the last century, the research on the space non-cooperative target docking technology started at home and abroad, and mainly takes a space robot arm system as a means. In the non-cooperative target docking technology, capturing a space target is an important link for a space manipulator system to execute tasks, and the link cannot avoid collision. Collisions may cause equipment damage and even failure of the capture task. Therefore, measures must be taken to suppress the collision rotation during the catching of the target.

At present, the racemization research of the space failure satellite is in a conceptual research stage, and proposed methods include an ion beam racemization method, a vortex racemization method, a brush racemization method, a magnetic moment racemization method and the like. In order to realize position maintenance between the spacecraft and the daily standard object, the ion beam racemization method only uses half of fuel for racemizing the rotary daily standard, and the other half of propellant is used for counteracting thrust generated by the ion beam blowing to the daily standard, so that more fuel is consumed. The eddy current racemization method is effective for metal material satellites. The magnetic moment racemization method is to load a magnetic moment coil on a failed satellite and carry out racemization through the electromagnetic effect.

Disclosure of Invention

The technical problem solved by the invention is as follows: the defects of the prior art are overcome, the multi-wheel-arm space robot facing the large rolling target is provided, and the problem of passive despun capture of spinning motion of a non-cooperative target is solved. The end effector is contacted with the surface of a captured object through a friction ball which can be controlled in an omnidirectional manner, and the captured object is captured and controlled through the cooperative control of a plurality of mechanical arms.

The technical solution of the invention is as follows: a multi-wheel-arm space robot facing a large rolling target comprises a mechanical arm and a mechanical arm tail end executing mechanism; the mechanical arm end executing mechanism comprises a mechanical arm and an end effector; the end effector is arranged at the tail end of the mechanical arm;

the end effector comprises an end effector mounting flange, a servo motor driver, a movable suspension, a linear module clutch system, a motor flange bracket, a servo motor, a linear module clutch driver, a fixed suspension, a limiting ball bearing, a driving wheel, a driving ball, an omnidirectional bearing, a laser measuring sensor and a driving ball bracket; one end of the motor flange support is provided with a movable suspension, a servo motor driver is arranged on the movable suspension, a servo motor and a driving wheel are arranged at the other end of the motor flange support, and the servo motor is used for controlling the rotation of the driving wheel; the driving ball support is fixedly connected with the mounting flange of the end effector through a connecting support, an omnidirectional bearing is arranged at the tail end of the driving ball support, and the driving ball is arranged in an envelope formed by the driving ball support and can rotate in the envelope under the driving of a driving wheel; the end effector mounting flange is used for connecting a mechanical arm; the linear module clutch driver is arranged on one surface of the fixed suspension, is connected with the movable suspension through the linear module clutch system and is used for realizing the up-and-down movement of the whole structure consisting of the movable suspension, the linear module clutch system, the motor flange bracket, the servo motor, the linear module clutch driver, the fixed suspension, the limiting ball bearing and the driving wheel; the limiting ball bearing is arranged on the other surface of the fixed suspension and is used for limiting the driving ball in cooperation with the omnidirectional bearing; and the driving ball support is provided with a laser measuring sensor for measuring the motion state of the surface of the driving ball.

Further, the device also comprises a reinforcing rib; the reinforcing rib is annular and is fixedly connected with the driving ball support.

Further, the device also comprises a one-way elastic bearing; the unidirectional elastic bearing is positioned at the tail end of the driving ball support, and the omnidirectional bearing is arranged on the unidirectional elastic bearing.

Further, the linear module clutch system is of a ball screw structure or a telescopic rod structure, so that the whole structure can move in the direction of the connecting rod.

Further, the driving ball support comprises at least three enveloping supports, and a ball bearing is arranged at the tail end of each enveloping support; the envelope support is elastic material, ball bearing and drive ball contact provide the pretightning force for the drive ball.

Further, the surface of the driving ball is coated with a silicon rubber coating.

Further, the driving wheel is an ohm wheel.

Compared with the prior art, the invention has the advantages that:

(1) the invention greatly reduces the energy consumption of the aircraft through active friction racemization, does not limit the material of a capture object, and is easy to realize;

(2) the invention utilizes the active friction technology to control the collision force in the process of capturing the target within a bearable range, thereby realizing the safe and stable capturing of the non-cooperative target.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic structural diagram of an end effector of a robot arm according to the present invention.

Detailed Description

The invention is further explained and illustrated in the following figures and detailed description of the specification.

Referring to fig. 1, the multi-wheel arm invention is composed of a universal mechanical arm and a full-freedom active friction end effector. The three coupled ohmic wheels are driven by three servo motors and are in close contact with the friction ball, so that six-degree-of-freedom omnidirectional control of the friction ball is realized. The friction ball is restrained by the omnidirectional bearing to be contacted with a capture object, and the contact object is controlled by the friction force generated by the contact. The specific implementation method comprises the following steps:

1. the mode of a traditional claw type or clamping piece type executing mechanism at the tail end of the catching mechanical arm is broken through. A brand-new 15 friction ball is adopted as a contact control mode, the problem of spin motion passive racemization capture of a non-cooperative target is effectively solved, the capture efficiency is higher, and the capture scheme is more intelligent.

2. Two sets of suspension systems are adopted: the three omnidirectional contact bearings are fixed on the fixed suspension and are kept in real-time contact with the friction ball through the unidirectional elastic device, so that omnidirectional constraint on the friction ball is realized; three coupled ohmic wheels are fixed to the movable suspension and contact the friction ball when power is required and are disengaged from the friction ball when power is not required.

3. Has a linear module clutch system. The three coupled ohm wheels are fixed on a movable suspension, and the movable suspension is driven by a linear module clutch system. When the end effector is not contacted with the capture object, the movable suspension is separated from the friction ball, and the friction ball is contacted with the surface of the capture object to passively follow the rotation; when the friction ball is completely contacted with the surface of the captured object, the power system is involved, and the clutch system drives the three coupled ohmic wheels to be contacted with the friction ball to provide power and realize the control of the captured object.

4. Has a pretightening force applying device. Three omnidirectional contact bearings are fixed on a fixed suspension and need to ensure real-time contact with the friction balls. The omnidirectional contact bearing is arranged on the unidirectional elastic device, and the unidirectional elastic device applies the radial pretightening force of the friction ball body in real time.

5. And a non-contact distributed coupling measurement scheme is adopted, three laser measurement sensors are coupled and distributed on the fixed suspension, and the motion measurement of the tail end of the end effector is realized by detecting the motion of the friction ball in three directions.

6. A coupled control motion planning algorithm is employed. The friction ball is driven by three coupled ohmic wheels, and the motion of the friction ball contacting with the surface of the capture object needs to be decoupled into the motion of the three ohmic wheels through an algorithm; and then the motion of the friction ball detected by the non-contact distributed coupling measurement sensor in three directions is decoupled into the motion of three ohm wheels in the driving direction, so that the closed-loop control of the motion of the friction ball is realized.

7. A surface treatment method with a large friction coefficient is adopted. The friction ball is contacted with the capture object, and the friction force between the ball body and the capture object determines the capture effect. A layer of viscous high-friction coating is formed on the surface of the friction ball by adopting a rubber coating technology, so that a good friction effect is ensured during capture.

Examples

Referring to fig. 1 and 2, a multi-wheel arm space robot facing a large rolling target comprises a mechanical arm and a mechanical arm end executing mechanism; the mechanical arm end executing mechanism comprises a mechanical arm 1 and an end effector 2; the end effector 2 is arranged at the tail end of the mechanical arm 1;

the end effector 2 comprises an end effector mounting flange 3, a servo motor driver 4, a movable suspension 5, a linear module clutch system 6, a motor flange support 7, a servo motor 8, a linear module clutch driver 9, a fixed suspension 10, a limiting ball bearing 11, an ohmic wheel 12, a driving ball 15, an omnidirectional bearing 16, a laser measuring sensor 17 and a driving ball support 18; one end of the motor flange support 7 is provided with a movable suspension 5, a servo motor driver 4 is arranged on the movable suspension 5, the other end of the motor flange support 7 is provided with a servo motor 8 and an ohmic wheel 12, and the servo motor 8 is used for controlling the rotation of the ohmic wheel 12; the driving ball support 18 is fixedly connected with the end effector mounting flange 3 through a connecting support 19, the tail end of the driving ball support 18 is provided with an omnidirectional bearing 16, and the driving ball is arranged in an envelope formed by the driving ball support 18 and can rotate in the envelope under the driving of the ohm wheel 12; the end effector mounting flange 3 is used for connecting the mechanical arm 1; the linear module clutch driver 9 is arranged on one surface of the fixed suspension 10, is connected with the movable suspension 5 through the linear module clutch system 6 and is used for realizing the up-and-down movement of the whole structure consisting of the movable suspension 5, the linear module clutch system 6, the motor flange bracket 7, the servo motor 8, the linear module clutch driver 9, the fixed suspension 10, the limiting ball bearing 11 and the ohm wheel 12; the limiting ball bearing 11 is arranged on the other surface of the fixed suspension 10 and is used for limiting the driving ball 15 by matching with the omnidirectional bearing 16; the driving ball support 18 is provided with a laser measuring sensor 17 for measuring the motion state of the surface of the driving ball 15. Also comprises a reinforcing rib 13; the reinforcing rib 13 is annular and is fixedly connected with the driving ball support 18. Also included is a one-way elastomeric bearing 14; the unidirectional elastic bearing 14 is positioned at the tail end of the driving ball bracket 18, and the omnidirectional bearing 16 is arranged on the unidirectional elastic bearing 14.

The linear module clutch system 6 is of a ball screw structure or a telescopic rod structure, so that the whole structure can move in the direction of the connecting rod.

The driving ball support 18 comprises at least three enveloping supports, and a ball bearing is arranged at the tail end of each enveloping support; the envelope support is elastic material, and ball bearing and drive ball 15 contact provide the pretightning force for drive ball 15.

The surface of the driving ball 15 is coated with a silicon rubber coating.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.

Claims

1. The utility model provides a multi-wheel arm space robot towards large-scale object that rolls which characterized in that: comprises a mechanical arm and a mechanical arm tail end executing mechanism; the mechanical arm end executing mechanism comprises a mechanical arm (1) and an end effector (2); the end effector (2) is arranged at the tail end of the mechanical arm (1);

the end effector (2) comprises an end effector mounting flange (3), a servo motor driver (4), a movable suspension (5), a linear module clutch system (6), a motor flange support (7), a servo motor (8), a linear module clutch driver (9), a fixed suspension (10), a limiting ball bearing (11), a driving wheel (12), a driving ball (15), an omnidirectional bearing (16), a laser measuring sensor (17) and a driving ball support (18); one end of the motor flange support (7) is provided with a movable suspension (5), a servo motor driver (4) is arranged on the movable suspension (5), the other end of the motor flange support (7) is provided with a servo motor (8) and a driving wheel (12), and the servo motor (8) is used for controlling the rotation of the driving wheel (12); the driving ball support (18) is fixedly connected with the end effector mounting flange (3) through a connecting support (19), an omnidirectional bearing (16) is arranged at the tail end of the driving ball support (18), the driving ball is arranged in an envelope formed by the driving ball support (18), and can rotate in the envelope under the driving of the driving wheel (12); the end effector mounting flange (3) is used for connecting the mechanical arm (1); the linear module clutch driver (9) is arranged on one surface of the fixed suspension (10) and connected with the movable suspension (5) through the linear module clutch system (6) and is used for realizing the up-and-down movement of an integral structure consisting of the movable suspension (5), the linear module clutch system (6), the motor flange bracket (7), the servo motor (8), the linear module clutch driver (9), the fixed suspension (10), the limiting ball bearing (11) and the driving wheel (12); the limiting ball bearing (11) is arranged on the other surface of the fixed suspension (10) and is used for limiting the driving ball (15) by matching with the omnidirectional bearing (16); and the driving ball support (18) is provided with a laser measuring sensor (17) for measuring the motion state of the surface of the driving ball (15).

2. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: also comprises a reinforcing rib (13); the reinforcing ribs (13) are annular and are fixedly connected with the driving ball support (18).

3. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: also comprises a one-way elastic bearing (14); the unidirectional elastic bearing (14) is positioned at the tail end of the driving ball support (18), and the omnidirectional bearing (16) is arranged on the unidirectional elastic bearing (14).

4. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: the linear module clutch system (6) is of a ball screw structure or a telescopic rod structure, so that the whole structure can move in the direction of the connecting rod.

5. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: the driving ball support (18) comprises at least three enveloping supports, and a ball bearing is arranged at the tail end of each enveloping support; the envelope support is elastic material, ball bearing and drive ball (15) contact, provide the pretightning force for drive ball (15).

6. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: the surface of the driving ball (15) is coated with a silicon rubber coating.

7. A large tumbling object-oriented multi-wheel arm space robot as claimed in claim 1, wherein: the driving wheel (12) is an ohm wheel.