CN211456938U

CN211456938U - Motor encoder correcting unit

Info

Publication number: CN211456938U
Application number: CN202020057739.7U
Authority: CN
Inventors: 刘峰; 郑铁帅
Original assignee: Shenzhen Fixed Card Sensor Technology Co ltd
Current assignee: Shenzhen Fixed Card Sensor Technology Co ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2020-09-08
Anticipated expiration: 2030-01-10

Abstract

The utility model discloses a motor encoder correcting unit relates to motor encoder technical field. The correcting device comprises a motor driver, a calibrated motor provided with a first encoder, a second encoder and correcting equipment; the motor driver is electrically connected with the calibrated motor, the calibrated motor is mechanically connected with the second encoder, the second encoder is electrically connected with the correcting device, and the correcting device is electrically connected with the motor driver and the calibrated motor respectively. The utility model discloses simple structure, it is with low costs, calibration effect is good.

Description

Motor encoder correcting unit

Technical Field

The utility model belongs to the technical field of the motor encoder technique and specifically relates to a motor encoder correcting unit is related to.

Background

For servo motors, photoelectric encoders are currently in common use. With the continuous improvement of the magnetic encoding technology, the magnetic encoding precision is more and more close to that of a photoelectric encoder, and the application of the magnetic encoding precision in a servo occasion is more and more wide. For a magnetic encoder, due to assembly errors, poor linearity of position feedback is caused, and performance such as running stability and positioning accuracy of a motor is further influenced. It is therefore desirable to calibrate the magnetic encoder prior to its measurement application to compensate for errors introduced by assembly and device variations.

One of the prior magnetic-encoding correction device schemes is to perform correction by adopting a passive dragging mode, and the correction process is as follows: 1. dragging the calibrated motor through the driving motor, and rotating forward and backward at different speeds; 2. the correction equipment compensates the information of the magnetic encoder through an algorithm by reading the position/speed information of the magnetic encoder on the passive motor and the position/speed information of the precise encoder on the passive motor shaft, so that the compensated information of the magnetic encoder approaches to the information of the precise encoder; 3. the compensation is saved to the PCBA on which the passive motor mounted magnetic encoder is located. The scheme has a complex structure, in addition, a passive dragging magnetic encoder motor is adopted for correction, a rotor of the magnetic encoder motor exists as an inertial load, and meanwhile, as a synchronous high-precision encoder needs to be installed on the magnetic encoder motor, the two parts need to be fastened through a large external force to ensure that the moving parts of the two magnetic encoders and the high-precision encoder are absolutely consistent. For a motor with the power of more than 400W, the rotor inertia is not negligible, the rotor inertia is increased along with the increase of the power of the motor, the synchronization of a rotor where a magnetic encoder is located and a moving part of a precise encoder needs to be ensured under the condition of high-speed dragging, an external fastening device needs a large locking force, fastening screws are easy to slip, and even a coupler is scrapped. In addition, a set of high-precision driver and a motor are required to be adopted as a power source in the correcting device. Since each set of motors using magnetic encoders needs to be calibrated, the cost of the calibration apparatus is also high.

The other is that a frequency converter is adopted to drag a passive motor provided with a magnetic encoder to operate in an open loop mode, and the frequency converter is used for correcting the encoder on the motor. Although simple structure, adopt the converter open loop to drag the motor operation and rectify, because the speed precision of converter with motor open loop operation is not high (speed fluctuation more than 1%), must make the correction result seriously influenced for position accuracy can only be controlled 400 ~ 500 angular seconds after the motor calibration, greatly reduced the range of application of magnetic encoding after the calibration.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a motor encoder correcting unit can calibrate motor encoder and calibration effect in real time.

An embodiment of the utility model provides a motor encoder correcting unit, the device includes motor drive, the motor of being calibrated that installs first encoder, second encoder and calibration equipment;

the motor driver is electrically connected with the calibrated motor, the calibrated motor is mechanically connected with the second encoder, the second encoder is electrically connected with the correcting device, and the correcting device is electrically connected with the motor driver and the calibrated motor respectively.

The utility model discloses motor encoder correcting unit has following beneficial effect at least: the motor does not need to be actively dragged, the motion of the calibrated motor is directly controlled, the condition of magnetic encoding correction is also met, the structure of the correction equipment is simplified, and the cost of the correction equipment is reduced.

According to the utility model discloses a motor encoder correcting unit of other embodiments, the motor that is calibrated is step motor or brushless motor or PMSM or servo motor.

According to the utility model discloses a motor encoder correcting unit of other embodiments, by the calibration motor with the second encoder passes through shaft coupling fixed connection.

According to the utility model discloses a motor encoder correcting unit of other embodiments, the second encoder pass through the shaft coupling with by the one end fixed connection of calibration motor shaft.

According to the utility model discloses a motor encoder correcting unit of other embodiments, first encoder the second encoder is magnetic encoder or capacitanc encoder or inductive encoder or photoelectric encoder.

According to the utility model discloses a motor encoder correcting unit of other embodiments, the precision of second encoder is higher than the precision of first encoder.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the calibration apparatus for a motor encoder according to the present invention.

Detailed Description

The conception and the resulting technical effects of the present invention will be described clearly and completely with reference to the following embodiments, so that the objects, features and effects of the present invention can be fully understood. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and other embodiments obtained by those skilled in the art without inventive labor based on the embodiments of the present invention all belong to the protection scope of the present invention.

In the description of the present invention, if an orientation description is referred to, for example, the directions or positional relationships indicated by "upper", "lower", "front", "rear", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, only for convenience of description and simplification of description, and it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. If a feature is referred to as being "disposed," "secured," "connected," or "mounted" to another feature, it can be directly disposed, secured, or connected to the other feature or indirectly disposed, secured, connected, or mounted to the other feature.

In the description of the embodiments of the present invention, if "a plurality" is referred to, it means one or more, if "a plurality" is referred to, it means two or more, if "greater than", "less than" or "more than" is referred to, it is understood that the number is not included, and if "more than", "less than" or "within" is referred to, it is understood that the number is included. If reference is made to "first" or "second", this should be understood to distinguish between features and not to indicate or imply relative importance or to implicitly indicate the number of indicated features or to implicitly indicate the precedence of the indicated features.

Referring to fig. 1, a schematic structural diagram of a motor encoder correction device in the present embodiment is shown. The apparatus includes a motor driver, a calibrated motor having a first encoder mounted thereon, a second encoder, and a correction device. The motor driver is electrically connected with the calibrated motor, the calibrated motor is mechanically connected with the second encoder, the second encoder is electrically connected with the correcting device, and the correcting device is electrically connected with the motor driver and the calibrated motor respectively.

In this embodiment, the calibrated motor is a stepping motor, a brushless motor, a permanent magnet synchronous motor, or a servo motor.

In this embodiment, as shown in fig. 1, the calibrated motor is fixedly connected to the second encoder through a coupler, and the second encoder is fixedly connected to one end of the shaft of the calibrated motor through the coupler. It will be appreciated that any mechanical hard coupling of the first encoder of the calibrated motor to the external second encoder may be achieved.

In this embodiment, the first encoder and the second encoder are both a magnetic encoder, a capacitive encoder, an inductive encoder, or a photoelectric encoder. The second encoder needs to be more accurate than the first encoder.

In this embodiment, the motor driver is connected to the calibrated motor through a UVW motor line. The motor drive may be a stand-alone drive or may be an integral drive mounted on the motor being calibrated.

The working process of the motor encoder correcting device is as follows:

the correction device is internally provided with a processor which acquires position information (comprising speed information and direction information) of the first encoder and the second encoder in real time. It should be noted here that the second encoder is connected to the calibrated motor through a coupling, and when the calibrated motor rotates, the second encoder rotates together with the calibrated motor. The position information refers to a real-time rotational position (e.g., how many degrees to turn) and a rotational direction (e.g., clockwise or counterclockwise) of the first/second encoder for one 360 ° rotation. After the processor acquires the position information of the first encoder and the second encoder, the processor extracts speed information and direction information to compare, generates a driving signal in real time according to the position information and sends the driving signal to the motor driver, and the motor driver drives the calibrated motor in real time according to the driving signal, so that the position information of the first encoder of the calibrated motor is the same as the position information of the external second encoder. Because the precision of the second encoder that chooses for use is higher than first encoder, through constantly calibrating first encoder in real time, improved by the control accuracy and the control effect of calibration motor. The subsequent pass checks the position information of the two encoders within 360 degrees, and if the same is true, the correction is valid.

When the correction device is powered on, the motor driver directly controls the current phase of the calibrated motor by using a torque control mode (or other modes in a motor control mode without a position sensor, such as harmonic injection, Hall signals and the like), locks the rotor of the calibrated motor to a fixed electrical angle and takes the angle as a reference position. And after the locking is finished, switching to position closed-loop control taking the position information of the second encoder as feedback. The calibrated motor is directly driven by the motor driver to rotate according to the required speed and direction.

Compared with the prior calibration scheme, on one hand, the utility model does not need to actively drag the motor, directly controls the motion of the calibrated motor, and also meets the condition of encoder correction, thereby simplifying the structure of the correction equipment and reducing the cost of the correction equipment; on the other hand, a high-precision second encoder is additionally arranged at the end part of the shaft of the calibrated motor, and in the working process of the motor driver, the position information of the high-precision second encoder which is hard-connected to the shaft of the calibrated motor is used as feedback to carry out closed-loop control, so that the control effect of the motor driver for driving the calibrated motor is ensured, the calibration effect is also ensured, and the position precision of the calibrated first encoder is controlled within 100 arc seconds. For the calibrated motor, because the mass of the rotating part of the high-precision second encoder is far smaller than that of the motor rotor, which is similar to the motor idling, the fastening force required for connecting the rotating part of the high-precision second encoder and the motor shaft is much smaller (compared with the prior art), and the fastening force is not increased along with the increase of the motor power, so that the wire sliding and the scrapping of the coupler caused by the overlarge locking force are avoided.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

Claims

1. A motor encoder correcting device is characterized by comprising a motor driver, a calibrated motor provided with a first encoder, a second encoder and correcting equipment;

2. The apparatus of claim 1, wherein the calibrated motor is a stepper motor or a brushless motor or a permanent magnet synchronous motor or a servo motor.

3. The motor encoder calibration device of claim 2, wherein the calibrated motor is fixedly connected with the second encoder through a coupling.

4. The apparatus of claim 3, wherein the second encoder is fixedly coupled to an end of the shaft of the calibrated motor via the coupling.

5. The motor encoder correction device of any one of claims 1 to 4, wherein the first encoder and the second encoder are both magnetic encoders, capacitive encoders, inductive encoders or photoelectric encoders.

6. The motor encoder calibration apparatus of claim 5, wherein the accuracy of said second encoder is higher than the accuracy of said first encoder.