Collision-Free control system for a multi-axially controllable manipulator

• US 5,549,439 A
• Filed: 10/07/1994
• Issued: 08/27/1996
• Est. Priority Date: 02/17/1992
• Status: Expired due to Fees

• Current Assignee: Sven Ploem
• Original Assignee: Sven Ploem
• Inventors: Ploem, Sven
• Primary Examiner(s): Merritt, Karen B.
• Assistant Examiner(s): MORSE, GREGORY ALLAN
• Application Number:
  US08/290,791
• Time in Patent Office: 690 Days
• Field of Search: 414/5, 414/680, 414/685, 378/204, 378/208, 378/209, 378/210
• US Class Current: 414/680
• CPC Class Codes: A61B 6/102 Protection against mechanical damage, e.g. anti-collision devices
• CPC Class Codes: A61B 6/4458 the source unit or the detector unit being attached to robotic arms
• CPC Class Codes: B25J 19/06 Safety devices
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02

Abstract

A collision-free control system comprising a multi-axially controllable manipulator having interconnected supporting arms which are movable by way of actuators in such a way that a free end of the manipulator can be positioned spatially and moved into various positions. The actuators are controlled via a miniature model of the manipulator which is operated manually and is equipped with a series of position transducers which are capable of delivering control signals for commanding the actuators in such a way that the manipulator and the miniature model thereof always assume identical positions.

Claims

1. A collision-free control system comprising a multi-axially controllable manipulator having interconnected supporting arms which are movable by means of controllable actuators in such a way that a free end of the manipulator can be positioned spatially and moved into various positions, and control means for commanding the actuators, said control means comprising a miniature model made substantially to scale of the manipulator, said miniature model being operated manually and being equipped with a series of position transducers which are capable of delivering control signals for commanding the actuators in such a way that the manipulator and the miniature model thereof always assume identical positions, said control means (4, 5) also comprising a miniature model (3'"'"') of an object (3) to be treated with the manipulator (1), wherein the scale ratio of the miniature model (3'"'"') of the object (3) to be treated is greater than the scale ratio of the miniature model (1'"'"') of the manipulator (1) in order to form a collision-free safety zone in the immediate surroundings of the object (3) to be treated.

2. The system according to claim 1, wherein the scale ratio of the miniature model (3'"'"') of the object (3) to be treated at one or more points is smaller than or equal to the scale ratio of the miniature model (1'"'"') of the manipulator (1) and at all other points is greater in order to form one or more holes in the safety zone.

3. The system according to claim 1, wherein the object (3) is placed on a multi-axially movable supporting surface (2), and wherein the control means (4, 5) comprise a miniature model (2'"'"') made substantially to scale of the object support (2), said model (2'"'"') being movable in the same way as the object support (2) and being connected thereto in such a way that the object support (2) and the miniature model (2'"'"') thereof always assume identical positions.

4. The system according to claim 3, wherein the object support is provided with actuators and position transducers for adjustment and determination of the position respectively of the object support (2), and wherein the miniature model (2'"'"') of the object support (2) is provided with position transducers which are connected only to the corresponding position transducers of the object support (2) by means of a comparison element, which in the presence of a difference signal between the position signals delivered by the two position transducers can deliver a control signal to an actuator belonging only to the particular position transducer of the object support (2), said actuator being controlled to reduce the difference signal to zero.

5. The system according to claim 4, wherein objects are placed in the movement area of the miniature models (1'"'"', 2'"'"') of the manipulator (1) and/or the object support (2) respectively in order to limit the movement area of the miniature models (1'"'"', 2'"'"'), and therefore of the manipulator (1) and/or the object support (2).

6. The system according to claim 1, wherein each position transducer of the miniature model (1'"'"') of the manipulator (1) is connected only to a corresponding position transducer of the manipulator (1) by means of a comparison element, which in the presence of a difference signal between the position signals delivered by the two position transducers can deliver a control signal to an actuator belonging only to the particular position transducer of the manipulator, said actuator being controlled to reduce the difference signal to zero.

7. The system according to claim 1, wherein objects are placed in the movement area of the miniature models (1'"'"', 2'"'"') of the manipulator (1) and/or the object support (2) respectively in order to limit the movement area of the miniature models (1'"'"', 2'"'"'), and therefore of the manipulator (1) and/or the object support (2).

12. The system according to claim 1, wherein the scale ratio of the miniature model (3'"'"') of the object (3) at one or more points is smaller than or equal to the scale ratio of the miniature model (1'"'"') of the manipulator (1) and at all other points is greater in order to form one or more holes in the safety zone.

13. The system according to claim 12, wherein the object is placed on a multi-axially movable supporting surface, and wherein the control means (4, 5) comprise a miniature model (2'"'"') made substantially to scale of the object support (2), said model (2'"'"') being movable in the same way as the object support (2) and being connected thereto in such a way that object support (2) and the miniature model (2'"'"') thereof always assume identical positions.

8. An X-ray apparatus comprising a manipulator (1) equipped with an X-ray source (6) and an image sensor (7), and an object support (2) on which an object (3) to be examined is placeable, the manipulator (1) being movable by means of controllable actuators in such a way that a free end (23) of the manipulator (1) can be positioned spatially and moved into various positions, the object support (2) being movable by means of controllable actuators in such a way that the object (3) can be moved into various positions, the apparatus further comprising an image screen (9) for displaying an image detected by the image sensor (7) and control means situated in an area (B) screened off from the X-ray source (6), the control means comprising a miniature model (1'"'"', 2'"'"') made substantially to scale of the manipulator (1) and of the object support (2'"'"'), said miniature models (1'"'"', 2'"'"') being operated manually and being equipped with a series of position transducers which are capable of delivering control signals for commanding the actuators in such a way that the manipulator (1) and the object support (2) and the respective miniature models (1'"'"', 2'"'"') thereof always assume identical positions, the apparatus being capable of being operated with a collision-free safety zone in the immediate surroundings of the object to be examined.

9. The X-ray apparatus according to claim 8, wherein the control means also comprise a miniature model (3'"'"') of the object (3) to be treated.

10. The X-ray apparatus according to claim 9, wherein the miniature model (3'"'"') of the object (3) is fixed on, or integrated with, the miniature model (2'"'"') of the object support (2).

11. A collision-free control system comprising a multi-axially controllable manipulator having interconnected supporting arms which are movable by means of controllable actuators in such a way that a free end of the manipulator can be positioned spatially and moved into various positions, and control means for commanding the actuators, said control means comprising a miniature model made substantially to scale of the manipulator, said miniature model being operated manually and being equipped with a series of position transducers which are capable of delivering control signals for commanding the actuators in such a way that the manipulator and the miniature model thereof always assume identical positions, said control means (4, 5) also comprising a miniature model (3'"'"') of an object (3) to be treated with the manipulator (1), wherein the scale ratio of the miniature model (1'"'"') of the manipulator (1) is locally greater than that of the miniature model (3'"'"') of the object (3) to be treated due to a material layer on the miniature model (1'"'"') of the manipulator (1) in order to form a safety zone.

14. The system according to claim 11, wherein each position transducer of the miniature model (1'"'"') of the manipulator (1) is connected only to a corresponding position transducer of the manipulator (1) by means of a comparison element, which in the presence of a difference signal between the position signals delivered by the two position transducers can deliver a control signal to an actuator belonging only to the particular position transducer of the manipulator, said actuator being controlled to reduce the difference signal to zero.

15. The system according to claim 11, wherein objects are placed in the movement area of the miniature models (1'"'"', 2'"'"') of the manipulator (1) and/or the object support (2) respectively in order to limit the movement area of the miniature models (1'"'"', 2'"'"'), and therefore of the manipulator (1) and/or the object support (2).