阅读说明：本技术 伺服控制丝杠传动装置和控制方法 (Servo control lead screw transmission device and control method ) 是由 匡晓霖 唐旭东 郭威 余东东 王凯 张程煜 于 2020-04-27 设计创作，主要内容包括：本说明书提供一种伺服控制丝杠传动装置和控制方法,传动装置包括伺服电机、丝杠螺母副、直线位移式电位器和控制器；丝杠螺母副包括丝杠螺母和丝杠；伺服电机用于驱动丝杠螺母转动和丝杠相对丝杠螺母平移；直线位移式电位器用于生成表示丝杠当前位置的反馈信号；控制器用于根据反馈信号确定丝杠的当前位置和伺服电机的当前转动位置,以及根据当前位置、当前转动位置和输入指令生成控制伺服电机转动的控制信号。本说明书提供的伺服控制丝杠传动装置仅使用直线位移式电位器即实现了丝杠当前位置和伺服电机当前转动位置的确定,无需在伺服电机中设置专门的角度检测传感器,结构得到简化,也减少因为角度传感器出现问题造成的传动装置故障。(The specification provides a servo control lead screw transmission device and a control method, wherein the transmission device comprises a servo motor, a lead screw nut pair, a linear displacement potentiometer and a controller; the screw nut pair comprises a screw nut and a screw; the servo motor is used for driving the screw nut to rotate and the screw to translate relative to the screw nut; the linear displacement type potentiometer is used for generating a feedback signal representing the current position of the screw rod; the controller is used for determining the current position of the lead screw and the current rotating position of the servo motor according to the feedback signal, and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotating position and the input instruction. The servo control lead screw transmission device provided by the specification only uses the linear displacement type potentiometer to determine the current position of the lead screw and the current rotating position of the servo motor, a special angle detection sensor is not required to be arranged in the servo motor, the structure is simplified, and transmission device faults caused by the problem of the angle sensor are reduced.)

1. A servo control lead screw transmission device is characterized by comprising a servo motor, a lead screw nut pair, a linear displacement potentiometer and a controller; the screw nut pair comprises a screw nut and a screw;

the servo motor is used for driving the lead screw nut to rotate, and then driving the lead screw to translate relative to the lead screw nut;

the linear displacement type potentiometer is used for generating a feedback signal representing the current position of the lead screw;

the controller is used for determining the current position of the lead screw and the current rotating position of the servo motor according to the feedback signal, and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotating position and an input instruction.

2. The apparatus of claim 1,

the servo motor is an annular inner rotor servo motor; and an annular inner rotor of the annular inner rotor servo motor is fixedly connected with the screw nut.

3. The apparatus of claim 2, wherein:

comprises a rotating drum; the rotary drum is sleeved on the outer peripheral side of the screw rod;

the annular inner rotor is fixed on the rotary cylinder and is fixedly connected with the screw nut through the rotary cylinder; the servo motor and the lead screw nut are located in different radial position areas of the drum.

4. The apparatus of claim 1,

a cavity is arranged at the axis of the lead screw; the linear displacement potentiometer is at least partially located within the cavity.

5. The apparatus according to any one of claims 1 to 4,

determining the current position of the lead screw and the current rotation position of the servo motor according to the feedback signal, comprising:

determining the current position of the lead screw according to the feedback signal;

calculating a position deviation according to the current position and the calibration position;

calculating the rotation angle of the servo motor according to the position deviation and the lead of the lead screw;

and determining the current rotating position according to the rotating angle and the rotating position of the servo motor corresponding to the calibration position.

6. The apparatus of claim 5,

a transmission gear is arranged between the output end of the servo motor and the screw nut;

the calculating a rotation angle of the servo motor according to the position deviation and the lead of the lead screw includes:

and calculating the rotation angle of the servo motor according to the rotation angle of the lead screw and the transmission ratio determined by the transmission gear.

7. The apparatus of claim 5,

the linear displacement potentiometer is a linear displacement sensor.

8. A control method for servo control lead screw transmission device is applied to a controller for servo control lead screw transmission device; it is characterized in that the preparation method is characterized in that,

the servo transmission device comprises a servo motor, a lead screw nut pair, a linear displacement potentiometer and a controller; the screw nut pair comprises a screw nut and a screw;

the servo motor is used for driving the lead screw nut to rotate, and then driving the lead screw to move relative to the lead screw nut;

the linear displacement type potentiometer is used for generating a feedback signal representing the current position of the lead screw;

the control method comprises the following steps: determining the current position of the lead screw and the current rotating position of the servo motor according to the feedback signal;

and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotation position and an input instruction.

9. The control method according to claim 8, wherein the linear displacement type potentiometer is a linear potentiometer;

determining the current position of the lead screw and the rotation position of the servo motor according to the feedback signal, comprising:

determining the current position of the lead screw according to the feedback signal;

calculating a position deviation according to the current position and the calibration position;

calculating the rotation angle of the servo motor according to the position deviation and the lead of the lead screw;

and determining the current rotating position according to the angle deviation and the rotating position of the servo motor corresponding to the calibration position of the servo motor.

10. The control method according to claim 9, characterized in that; a transmission gear is arranged between the output end of the servo motor and the screw nut;

calculating a rotation angle of the servo motor according to the position deviation and the lead of the lead screw, including: calculating a rotation angle of the lead screw according to the position deviation and the lead of the lead screw;

and calculating the rotation angle of the servo motor according to the rotation angle of the lead screw and the transmission ratio determined by the transmission gear.

Technical Field

The invention relates to the technical field of mechanical automation, in particular to a servo control lead screw transmission mechanism.

Background

The servo-controlled screw transmission mechanism has wide application in occasions where precise control of equipment action is required to be realized, and the typical application is the steering engine of various aircrafts.

FIG. 1 is a schematic diagram of a typical servo-controlled lead screw drive. As shown in fig. 1, a typical servo-controlled lead screw transmission mechanism includes a controller 01, a servo motor 02, a lead screw nut pair 03 and a displacement sensor 04, and the servo motor 02 further includes an angle sensor. After receiving the input command, the servo controller 01 determines the current angular position of the servo motor 02 through the angle sensor and the extending position of the screw in the screw nut pair determined by the position sensor 04 to generate a control signal, so as to control the action of the servo motor.

At present, the servo control screw transmission mechanism still uses an angle sensor to detect the position of a motor, and the working reliability of the angle sensor directly influences the safety of the angle sensor; in addition, the structure such as the angle sensor also increases the size of the servo motor, so that the size of the whole servo control transmission structure is increased.

Disclosure of Invention

The present specification provides a servo control lead screw transmission device and a control method, which simplify the structure of the servo control lead screw transmission device and enable servo control.

The specification provides a servo control lead screw transmission device, which comprises a servo motor, a lead screw nut pair, a linear displacement potentiometer and a controller; the screw nut pair comprises a screw nut and a screw;

the servo motor is used for driving the lead screw nut to rotate, and then driving the lead screw to translate relative to the lead screw nut;

the linear displacement type potentiometer is used for generating a feedback signal representing the current position of the lead screw;

the controller is used for determining the current position of the lead screw and the current rotating position of the servo motor according to the feedback signal, and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotating position and an input instruction.

Optionally, the servo motor is an annular inner rotor servo motor; and an annular inner rotor of the annular inner rotor servo motor is fixedly connected with the screw nut.

Optionally, a drum; the rotary drum is sleeved on the outer peripheral side of the screw rod;

the annular inner rotor is fixed on the rotary cylinder and is fixedly connected with the screw nut through the rotary cylinder; the servo motor and the lead screw nut are located in different radial position areas of the drum.

Optionally, a cavity is arranged at the axis of the lead screw; the linear displacement potentiometer is at least partially located within the cavity.

Optionally, the determining the current position of the lead screw and the current rotation position of the servo motor according to the feedback signal includes:

determining the current position of the lead screw according to the feedback signal;

calculating a position deviation according to the current position and the calibration position;

calculating the rotation angle of the servo motor according to the position deviation and the lead of the lead screw;

and determining the current rotating position according to the rotating angle and the rotating position of the servo motor corresponding to the calibration position.

Optionally, a transmission gear is arranged between the output end of the servo motor and the screw nut;

the calculating a rotation angle of the servo motor according to the position deviation and the lead of the lead screw includes:

and calculating the rotation angle of the servo motor according to the rotation angle of the lead screw and the transmission ratio determined by the transmission gear.

Optionally, the linear displacement potentiometer is a linear displacement sensor.

The present specification provides a control method of a servo control lead screw transmission device, applied to a controller of the servo control lead screw transmission device;

the servo transmission device comprises a servo motor, a lead screw nut pair, a linear displacement potentiometer and a controller; the screw nut pair comprises a screw nut and a screw;

the servo motor is used for driving the lead screw nut to rotate, and then driving the lead screw to move relative to the lead screw nut;

the linear displacement type potentiometer is used for generating a feedback signal representing the current position of the lead screw;

the control method comprises the following steps: determining the current position of the lead screw and the current rotating position of the servo motor according to the feedback signal;

and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotation position and an input instruction.

Optionally, the linear displacement potentiometer is a linear potentiometer;

determining the current position of the lead screw and the rotation position of the servo motor according to the feedback signal, comprising:

determining the current position of the lead screw according to the feedback signal;

calculating a position deviation according to the current position and the calibration position;

calculating the rotation angle of the servo motor according to the position deviation and the lead of the lead screw;

and determining the current rotating position according to the angle deviation and the rotating position of the servo motor corresponding to the calibration position of the servo motor.

Optionally, a transmission gear is arranged between the output end of the servo motor and the screw nut;

calculating a rotation angle of the servo motor based on the position deviation and the lead of the lead screw, including: calculating a rotation angle of the lead screw according to the position deviation and the lead of the lead screw;

and calculating the rotation angle of the servo motor according to the rotation angle of the lead screw and the transmission ratio determined by the transmission gear.

Compared with a servo control lead screw transmission device in the prior art, the servo control lead screw transmission device provided by the specification only uses a linear displacement potentiometer to determine the current position of a lead screw and the current rotation position of a servo motor, and a special angle detection sensor is not required to be arranged in the servo motor. Since a rotational angle detection sensor is not required, the structure of the servo motor can be simplified. The angle detection sensor has the characteristics of high detection precision and the like, and when the screw transmission mechanism has better transmission precision, the angle detection sensor can be adopted to realize the accurate measurement of the current position of the screw and the current rotating position of the servo motor. And because an angle sensor in the servo motor is cancelled, the transmission device faults caused by the problems of the angle sensor can be reduced.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic diagram of a typical servo-controlled lead screw drive;

FIG. 2 is a schematic structural diagram of a servo-controlled lead screw transmission device provided by an embodiment;

FIG. 3 is a schematic cross-sectional view of a portion of the components of the servo control actuator;

FIG. 4 is a flow chart of the lead screw drive apparatus of the present embodiment for determining the current position of the servo motor;

FIG. 5 is a flow chart of a control method provided by an embodiment;

in fig. 1: 01-a controller, 02-a servo motor, 03-a screw-nut pair and 04-a displacement sensor; fig. 2 to fig. 3: the method comprises the following steps: 11-a servo motor, 10-a screw-nut pair, 12-a screw-nut, 13-a screw, 14-a linear displacement potentiometer, 15-a controller, 16-a front end cover, 17-a shell, 18-a rear end cover, 19-a bearing, 20-a positioning sleeve and 21-a rotary drum.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

The embodiment of the specification provides a servo control transmission device. Fig. 2 is a schematic structural diagram of a servo control screw 13 transmission device provided by the embodiment, and fig. 3 is a schematic sectional diagram of a part of components of the servo control transmission device. As shown in fig. 2 and 3, in the present embodiment, the servo control screw 13 transmission device includes a servo motor 11, a screw nut 12, a screw nut pair 10, a linear displacement potentiometer 14 and a controller 15; the spindle nut pair 10 includes a spindle 13 and a spindle nut 12.

It should be noted that the servo motor 11 in the present embodiment has a meaning of a motor that can realize servo feedback control by a closed loop, but it does not include an angle sensor for detecting a motor rotation angle, which is provided in a conventional servo motor.

Of course, the servo control screw 13 transmission mechanism further comprises a front end cover 16, a shell 17 and a rear end cover 18 for realizing the integration of the equipment, a bearing 19 for reducing friction, and a positioning sleeve 20 for realizing the positioning of related components. Since such components are not the core invention of the embodiments of the present invention, they will not be described below; corresponding technical contents can be found in the relevant technical literature.

The output end of the servo motor 11 is connected to the screw nut 12 for driving the screw nut 12 to rotate, and then driving the screw 13 to translate relative to the screw nut 12, so that the screw 13 executes a control action. The linear displacement potentiometer 14 is at least partially fixedly connected with the lead screw 13; the linear displacement type potentiometer 14 is used to detect the current position of the lead screw 13 and generate a feedback signal representing the current position of the lead screw 13.

The controller 15 is connected to the output ends of the servo motor 11 and the linear displacement type position finder, and is configured to receive a feedback signal generated by the linear displacement type potentiometer 14, determine the current position of the lead screw 13 and the current rotation position of the servo motor 11 according to the feedback signal, and generate a control signal for controlling the rotation of the servo motor 11 according to the current position of the lead screw 13, the current rotation position of the servo motor 11, and an input instruction.

Specifically, the controller 15 determines the rotation direction and the rotation amount of the servo motor 11 according to the current position of the lead screw 13 and the control instruction, and determines which windings of the servo motor 11 are energized so that it can reasonably realize the rotation according to the current rotation position of the servo motor 11.

According to the connection relation, in the rotation process of the servo motor 11, the lead screw 13 moves relative to the lead screw nut 12, and each current rotation angle in the rotation process of the servo motor 11 corresponds to the current position of at least one lead screw 13; conversely, in the case where the current position of the lead screw 13 is determined, it is possible to determine the current position of the servo motor 11 reversely from the current position of the lead screw 13, and then determine how to generate the control signal for controlling the rotation of the servo motor 11.

Compared with the servo control lead screw 13 transmission device in the prior art, the servo control lead screw 13 transmission device provided by the embodiment realizes the determination of the current position of the lead screw 13 and the current rotation position of the servo motor 11 only by using the linear displacement type potentiometer 14, and does not need to arrange a special angle detection sensor in the servo motor 11. Since the angle detection sensor is not required, the structure of the servo motor 11 can be simplified. And because the angle sensor in the servo motor 11 is eliminated, the transmission failure caused by the problem of the angle sensor can be reduced.

The potentiometer has the characteristics of high detection precision and the like, and when the transmission mechanism of the lead screw 13 has better transmission precision, the potentiometer can be adopted to accurately measure the current position of the lead screw 13 and the current rotating position of the servo motor 11.

As shown in fig. 3, the servomotor 11 in this embodiment is a ring-shaped inner rotor servomotor. The annular inner rotor of the inner rotor servo motor 11 is fixedly connected with a screw nut 12, and the inner rotor can be directly sleeved on the outer peripheral surface side of a screw 13. In this way, the overall size of the actuator of the servo-controlled spindle 13 can be reduced, so that the actuator can be fitted as far as possible to devices of a strictly defined size (such as missile devices). Of course, in other embodiments, in the case that the servo motor 11 is an inner rotor, it may also be similar to the conventional inner rotor servo motor 11; alternatively, the servo motor 11 may employ an external rotor motor 11.

With reference to fig. 3, the apparatus of the present embodiment further includes a rotating drum 21, and the rotating drum 21 is sleeved on the outer periphery of the screw 13. The inner rotor servo motor 11 is fixed to the outer peripheral side of the drum 21 and is fixedly connected to the screw nut 12 through the drum 21. In order to reduce the diameter of the gear as much as possible, the servomotor 11 and the spindle nut 12 are located in different radial position regions of the drum 21 in the present embodiment.

In this embodiment, the servo motor 11 is a brushless dc servo motor 11. In other embodiments, the servo motor 11 may be another type of motor as long as the foregoing control method is satisfied, and the present invention is not particularly limited.

In this embodiment, in order to ensure good transmission accuracy and improve transmission efficiency, the screw-nut pair 10 preferably employs a ball screw-nut pair.

With continued reference to fig. 3, in the present embodiment, the structure of the transmission device is further reduced. The axis of the screw 13 of the screw-nut pair 10 is provided with a cavity. The aforementioned linear displacement type potentiometer 14 is provided in the cavity for detecting the current position of the lead screw 13. In other embodiments, a linear displacement sensor may be provided outside the lead screw 13.

Fig. 4 is a flowchart illustrating a control method for the controller 15 to determine the current position of the servo motor by the screw 13 driving device provided in the embodiment. As shown in fig. 4, the control method includes steps S101-S104.

S101: and determining the current position of the screw according to the feedback signal.

In a specific application of this embodiment, after obtaining the feedback signal corresponding to the current position of the lead screw 13, the current position of the lead screw 13 can be quickly calculated according to the signal corresponding to the calibrated position (a specific lead screw position). Of course, in other embodiments, the controller 15 may determine the current position of the lead screw 13 by directly looking up the lookup table through the feedback signal in the manner of a lookup table.

S102: and calculating the position deviation according to the current position and the calibration position of the screw rod.

The current position is represented by l, and the calibration position is represented by l₀Indicates that the position deviation is l-l₀。

S103: and calculating the rotation angle of the servo motor according to the position deviation and the lead of the lead screw.

In this embodiment, when the lead screw 13 translates by a lead d, the corresponding rotation angle is 2 π. In the case of the aforementioned positional deviation determination, the rotation angle of the corresponding servo motor 11 may be adoptedAnd (4) calculating. Of course, the aforementioned calculation method considers the case of directly fixedly connecting the output end of the servo motor 11 and the screw nut 12. In other embodiments, if a transmission gear is provided between the output end of the servo motor 11 and the lead screw nut 12, the rotation angle of the servo motor 11 can be calculated according to the transmission ratio of the transmission gear and the aforementioned θ.

S104: and determining the current rotating position according to the rotating angle and the rotating position of the corresponding servo motor at the calibration position.

For example, the rotational position of the servo motor 11 at the calibration position is θ₀Then the current rotation position is theta₀+ θ; from the current rotational position it can be determined how the windings of the servomotor 11 should be energized to cause the servomotor 11 to rotate.

In other embodiments, the controller 15 may also determine the current position of the servo motor 11 by directly looking up the look-up table through the feedback signal in a look-up table manner.

In this embodiment, the linear displacement potentiometer is preferably a linear potentiometer; of course, in other embodiments, a non-linear point finder may also be employed.

In addition to providing the servo control transmission device, the embodiment of the present specification further provides a control method of the device. The control method is applied to the controller 15 in the aforementioned transmission. FIG. 5 is a flow chart of a control method provided by an embodiment; as shown in fig. 5, the control method includes steps S201 to S202.

S201: and determining the current position of the screw rod and the current rotating position of the servo motor according to the feedback signal.

In a specific application, step S201 may determine the current position of the lead screw 13 and the current rotation position of the servo motor 11 by using the aforementioned volume steps in S101 to S104.

S202: and generating a control signal for controlling the rotation of the servo motor according to the current position, the current rotating position and the input instruction.

After determining the current position of the lead screw 13 and determining the position that the lead screw 13 needs to reach by inputting a command, the controller 15 may determine the rotational direction of the servo motor 11. Subsequently, the controller 15 generates a control signal for controlling the energization of the winding of the servo motor 11 based on the aforementioned rotation direction and the current rotation position determination of the servo motor 11, and then controls the rotation of the servo motor 11.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention.