Method and device for the cyclic digital transmission of a position value of a moving object with inertial mass

Patent metadata

Field	Value
Publication number	US-10193483-B2
Application number	US-201715593174-A
Country	US
Kind code	B2
Filing date	May 11, 2017
Priority date	Jun 20, 2011
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

In a method and device for the cyclic digital transmission of a position value of a moving object with inertial mass, the value range of the transmitted position value is restricted such that no complete rotation or, in the case of a linear motion, other complete period caused by mechanical conditions may be mapped, and the actual position is formed by detecting value-range exceedances in an evaluation unit.

First claim

What is claimed is:

1. A method for closed-loop control of a drive, comprising:
recurrently detecting a position value over time; and
transmitting associated information to a control device;
wherein the position value includes at least two values, including a partial-angle value, a fine-angle value, and/or digital values, a first value being denotable with a whole number, and a position-value range being assigned to each number, each position range including a first value being assigned mutually separate sub-ranges of the position range, each of these sub-ranges including a second value denotable as a whole number, the second value being transmitted prior in time to the first value;
wherein:
(i) after a newly detected second value has been transmitted, a model value is determined for the first value from the newly detected and a previously transmitted second value, and the position value determined is used by a control device to determine an updated value of a manipulated variable of the control device; and
(ii) after the newly detected second value has been transmitted, the newly detected first value is transmitted, and the model value determined is compared to the newly detected first value, and an action is carried out if they do not agree,

wherein the action includes communication and/or display of warning information, bringing the drive to rest, and/or transferring the drive into a safe state;
wherein the manipulated variable includes a voltage space vector and/or a stator-voltage space vector of an electric motor of the drive.

2. The method according to claim 1 , wherein the method include repeating the step (i).

3. The method according to claim 1 , wherein:
in transmitting the second value, check information and/or a CRC datum, is transmitted, and upon detection of a faulty transmission, an action is triggered, including display and/or communication of warning information, switching off the drive, and/or initiating a safe state of the drive, and/or
in transmitting the first value, further check information and/or a CRC datum, is transmitted, and upon detection of a faulty transmission, an action is triggered, including display and/or communication of warning information, switching off the drive, and/or initiating a safe state of the drive.

4. The method according to claim 1 , wherein the method includes cyclic digital transmission of a position value of a moving object with an inertial mass, at a known maximum attainable velocity of the object, the value range of the transmitted position value being restricted such no complete rotation or other complete period caused by mechanical conditions may be mapped, and an actual, complete position being formed by detecting value-range exceedances in an evaluation unit; and
wherein (a) at a first instant, a position is transmitted which is not or is far less sharply value-range-restricted than in continuous operation; (b) the value range is determined in a manner that an amount of a path difference occurring in one scanning cycle at maximum velocity is less than half the selected value range, the value range being selected to be as small as possible; and/or (c) a difference relative to a previous position with a same value-range restriction is transmitted.

5. The method according to claim 1 , wherein the method includes cyclic digital transmission of a position value of a moving object with an inertial mass, at a known maximum attainable velocity of the object, the value range of the transmitted position value being restricted compared to the value range of possible position values, so that no complete rotation or other complete period caused by mechanical conditions may be mapped, an actual position being determined by forming an estimated value for the position from a previous position and at previously determined velocity, and correcting it by the value-range-restricted transmitted position value; and
wherein (a) by comparing the value-range-restricted estimated position value to the value-range-restricted transmitted position value, a value-range exceedance is ascertained and utilized to correct the estimated value; (b) one time at a beginning, a position and a velocity is transmitted whose value range includes the range of possible positions and velocities occurring; and/or (c) a difference relative to the previous position with a same value-range restriction is transmitted.

6. The method according to claim 1 , wherein the method includes cyclic digital transmission of a position value of a moving object with inertial mass, at a known maximum attainable velocity of the object, the position value including at least two values, including a partial-angle value, a sub-angle value, a fine-angle value, and/or digital values, a first value being denotable with a whole number, and a position range being assigned to each number, each number denoting a respective assigned position range, each position range including a first value being assigned mutually separate sub-ranges of the position range, each of these sub-ranges including a second value denotable as a whole number, at a first instant, a position value being detected and thereafter associated first and second values being transmitted;
wherein a further position value is detected and an associated, newly detected, second value is transmitted; and
wherein, from the newly detected second value and the previously detected second value, the position range characterized by the first value is determined, and the first value belonging to the newly detected position value.

7. The method according to claim 1 , wherein the method includes digital transmission of a position value of a moving object with inertial mass, the position value including at least two values, including a partial-angle value, a sub-angle value, a fine-angle value, and/or digital values, a first value being denotable with a whole number, and a position range being assigned to each number, each number denoting a respective assigned position range, each position range including a first value being assigned mutually separate sub-ranges of the position range, each of the sub-ranges including a second value denotable as a whole number, at a first instant, a position value and an initial velocity being detected and thereafter associated first and second values being transmitted;
wherein a further position value is detected and an associated, newly detected, second value is transmitted, an updated velocity being determined and transmitted, at least with sufficient accuracy, a quantity of exceeded ranges, fine-angle ranges and/or sub-angle ranges, assigned to the second value as velocity; and
wherein, from the newly detected second value and the previously detected second value, the position range characterized by the first value is determined, and also the first value belonging to the newly detected position value, in doing which, the velocity being taken into account.

8. The method according to claim 1 , wherein the position value includes an angular value of a rotating part having an inertial mass having a moment of inertia, or a path-position value of a moving part that has an inertial mass.

9. The method according to claim 1 , wherein the transmitting is repeated recurrently over time or is repeated cyclically at regular time intervals, steps (i) and (ii) being carried out repeatedly in succession.

10. The method according to claim 1 , wherein the position value is an angular value or a linear position, velocity being an angular velocity or a velocity occurring in a linear direction.

11. The method according to claim 1 , wherein the first and second values are assigned to a track and/or an encoder track, each, the first value being

Assignees

• Sew Eurodrive Gmbh & Co

Inventors

• Simon Olaf

Classifications

• G01D5/00

  Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable (G01D3/00 takes precedence; specially adapted for apparatus giving results other than momentary value of variable G01D1/00) · CPC title

• H02P21/12 Primary

  Stator flux based control involving the use of rotor position or rotor speed sensors · CPC title

• H02K11/21

  Devices for sensing speed or position, or actuated thereby (specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14) · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• G01D21/00 Primary

  Measuring or testing not otherwise provided for · CPC title