SELF-SWITCHING, REVERSIBLE LINEAR ACTUATOR HAVING BIFILAR CONTROL

• US 20170085203A1
• Filed: 06/02/2015
• Published: 03/23/2017
• Est. Priority Date: 06/03/2014
• Status: Active Grant

• Current Assignee: Sonceboz Automotive SA (Société industrielle de Sonceboz SA)
• Original Assignee: MMT SA
• Inventors: Andrieux, Ga?l, Foucaut, Antoine
• Granted Patent: US 10,122,311 B2
• Time in Patent Office: Days
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
• CPC Class Codes: H02K 29/06 with position sensing devices H02K29/03 takes precedence
• CPC Class Codes: H02K 7/06 Means for converting reciprocating motion into rotary motion or vice versa
• CPC Class Codes: H02P 23/0004 Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
• CPC Class Codes: H02P 23/0077 Characterised by the use of a particular software algorithm
• CPC Class Codes: H02P 23/24 Controlling the direction, e.g. clockwise or counterclockwise
• CPC Class Codes: H02P 23/30 Direct torque control [DTC] or field acceleration method [FAM]
• CPC Class Codes: H02P 25/064 of the synchronous type
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position

Abstract

A mechatronic assembly for linearly driving a member includes a control unit and an actuator, the control unit including a control algorithm and a power bridge, the algorithm controlling the power bridge, the power bridge providing a bifilar electrical signal consisting of a torque signal and a direction signal, the actuator including an electric motor which does not have an N-phase multiphase brush, binary probes for detecting the position of the rotor of the motor, a device for transforming the rotational movement of the rotor into a linear movement of the control member, power switches capable of powering the N phases of the motor on the basis of the bifilar electrical signal, and the state of the power switches is controlled directly by a signal from the detection probes.

Claims

1. A mechatronic assembly for the linear drive of a member comprising a control unit and an actuator, with the control unit comprising a control algorithm and a power bridge, with the algorithm controlling the power bridge, with the power bridge providing a bifilar electric signal including a torque signal and a direction signal, with the actuator comprising a polyphase brushless electric motor having N phases, binary probes for detecting a position of the rotor of the motor, a transmission transforming rotational movement of the rotor into a linear movement of the control unit, power switches operably powering the N phases of the motor on the basis of the bifilar electric signal, and a state of the power switches being directly controlled by a signal from the detection probes.

2. A mechatronic assembly according to claim 1, wherein the N-phase polyphase motor includes N unipolar or bipolar coils, or N*2 unipolar half-coils.

3. A mechatronic assembly according to claim 1, wherein the binary probes for detecting the position of the rotor are powered by the bifilar electric signal.

4. A mechatronic assembly according to claim 1, wherein the movement transformation transmission has at least one nut connected to the rotor of the motor and at least one threaded portion connected to the actuator control member and in that the rotor drives a position-return device through a planetary reduction gearing.

5. A mechatronic assembly according to claim 1, wherein the movement transformation transmission has at least one nut connected to the rotor and a second nut connected to the stator case, with each one cooperating with two portions of the control member having threads in opposite directions and in that the rotor drives the position-return device through a planetary reduction gearing.

6. A mechatronic assembly according to claim 1, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magneto-sensitive element being adapted to read the axial position of the control member.

7. A mechatronic assembly according to claim 5, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magnetization pattern of the magnet being adapted to read the axial position of the control member during the helical movement thereof.

8. A mechatronic assembly according to claim 5, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magnetization pattern of the magnet being axisymmetric.

9. A mechatronic assembly for the linear drive of a member comprising a control unit and an actuator, with the control unit comprising a servo-control algorithm and a power bridge, with the algorithm controlling the power bridge, with the power bridge outputting a bifilar electric signal including a torque signal and a direction signal, with the actuator comprising a polyphase brushless electric motor having N phases, binary probes for detecting a position of the rotor of the motor, a transmission operably transforming rotational movement of the rotor into a linear movement of the control unit, a torsion spring operably returning to the reference position, power switches operably powering the N phases of the motor from the bifilar electric signal, and a state of the power switches being is directly controlled by a signal from the detection probes.

10. A mechatronic assembly according to claim 9, wherein the N-phase polyphase motor includes N unipolar or bipolar coils, or N*2 unipolar half-coils.

11. A mechatronic assembly according to claim 9, wherein the binary probes for detecting the position of the rotor are powered by the bifilar electric signal.

12. A mechatronic assembly according to claim 9, wherein the movement transformation transmission has at least one nut connected to the rotor of the motor and at least one threaded portion connected to the actuator control member and in that the rotor drives the position-return spring through a planetary reduction gearing.

13. A mechatronic assembly according to claim 9, wherein the movement transformation transmission has at least one nut connected to the rotor and a second nut connected to the stator case, with each one cooperating with two portions of the control member having threads in opposite directions and in that the rotor drives the position-return spring through a planetary reduction gearing.

14. A mechatronic assembly according to claim 9, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magneto-sensitive element being adapted to read the axial position of the control member.

15. A mechatronic assembly according to claim 13, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magnetization pattern of the magnet being adapted to read the axial position of the control member during helical movement thereof.

16. A mechatronic assembly according to claim 13, further comprising a position sensor comprising a magnet connected to the control member and a magneto-sensitive element connected to the control unit, and the magnetization pattern of the magnet being axisymmetric.

17. A mechatronic assembly according to claim 9, further comprising a winding axis of the torsion spring being concentric with an axis of rotation of the polyphase motor.

18. A mechatronic assembly according to claim 9, further comprising an angular path of the torsion spring being mechanically limited by a protrusion connected to the spring itself or to one of the elements of the planetary reduction gearing moving in a limited circular space.