CN112955783A

CN112955783A - Motor module, scanning module, distance measuring device and control method

Info

Publication number: CN112955783A
Application number: CN201980031832.0A
Authority: CN
Inventors: 杨阳; 陈旭; 陈鸿滨
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-06-11
Also published as: WO2021056470A1

Abstract

A motor module and a control method thereof, a scanning module and a control method thereof, a laser radar and a control method thereof and a control device thereof are provided. The motor module comprises a first motor and a second motor, and the control method comprises the following steps: inputting a set rotational speed value to the first motor and the second motor (S101); acquiring a phase relation between the first motor and the second motor in a motor rotation process (S102); correcting the speed and/or position of the first motor and/or the second motor by the phase relationship of the first motor and the second motor to ensure that the first motor and the second motor rotate at the set rotation speed value and the target phase relationship (S103). The control method and the control device can more effectively and accurately control the rotation of the first motor and the second motor, so that the accuracy of the distance measuring device in measuring the detected object is improved.

Description

Motor module, scanning module, distance measuring device and control method

Description

Technical Field

The invention relates to the technical field of distance measuring devices, in particular to a motor module and a control method thereof, a scanning module and a control method thereof, and a laser radar and a control method thereof.

Background

The distance measuring device of the mechanical rotation type laser radar generally comprises a scanning module, wherein the scanning module is used for changing the direction of light emitted by a light source to be initial, the scanning module generally comprises two prisms, and the two prisms are respectively driven to rotate by two rotating motors, so that the propagation direction of the light is changed.

Therefore, in view of the above problems, the present invention provides a motor module and a control method thereof, a scanning module and a control method thereof, a laser radar and a control method thereof, and a control device.

Disclosure of Invention

The present invention has been made to solve at least one of the above problems. Specifically, a first aspect of the present invention provides a motor module control method, where the motor module includes a first motor and a second motor, and the control method includes:

inputting a set rotating speed value to the first motor and the second motor;

acquiring a phase relation between the first motor and the second motor in a motor rotation process;

and correcting the speed and/or position of the first motor and/or the second motor through the phase relationship of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the rotating speed set value and the target phase relationship.

A second aspect of the present invention provides a scan module control method,

the scanning module comprises a motor module and an optical element module;

the motor module comprises a first motor and a second motor, the optical element module comprises a first optical element and a second optical element, the first motor is used for driving the first optical element to rotate, and the second motor is used for driving the second optical element to rotate;

the scanning module control method comprises the following steps:

the first motor and the second motor are controlled by the motor module control to respectively drive the first optical element and the second optical element to rotate so as to ensure that the first optical element and the second optical element rotate at the rotating speed set value and the target phase relation.

A third aspect of the present invention provides a method for controlling a distance measuring device, the method comprising:

emitting a light pulse along an outgoing light path;

the first motor and the second motor are controlled by the scanning module control method to respectively drive the first optical element and the second optical element to rotate so as to ensure that the first optical element and the second optical element rotate according to the rotating speed set value and the target phase relationship, and the rotating first optical element and the rotating second optical element are respectively positioned on the light pulse emitting path and used for changing the transmission direction of the light pulse;

receiving at least a portion of the transmitted light pulses reflected back through the object;

and acquiring the distance between the distance measuring device and the object according to the received light pulse.

A fourth aspect of the present invention provides a motor module, including a motor module and a control module, where the motor module includes a first motor and a second motor, and the control module is configured to:

inputting a set rotating speed value to the first motor and the second motor;

A fifth aspect of the present invention provides a scanning module, which includes a motor module, an optical element module, and a control module;

the control module is used for:

A sixth aspect of the present invention provides a distance measuring apparatus, characterized by comprising:

a light source for emitting light pulses along an exit light path;

the scanning module control device is configured to control the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate, so as to ensure that the first optical element and the second optical element rotate according to the set rotation speed value and the target phase relationship, and the rotating first optical element and the rotating second optical element are respectively located on the light pulse emitting light path and are used to change a transmission direction of the light pulse;

a detector for receiving at least part of the emitted light pulses reflected back through the object and for deriving a distance of the ranging device from the received light pulses.

According to the motor module, the control method of the motor module, the scanning module, the control method of the scanning module, the laser radar and the control method of the laser radar, after the phase relationship between the first motor and the second motor in the rotation process of the first motor and the second motor is obtained, the speed and/or the position of the first motor and/or the second motor is corrected through the phase relationship between the first motor and the second motor, so that the first motor and the second motor are enabled to rotate according to the rotating speed set value and the target phase relationship, the rotation of the first motor and the second motor is controlled more effectively and accurately, and the accuracy of a distance measuring device for measuring a detected object is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 shows a schematic flow chart of a motor module control method in an embodiment of the invention;

FIG. 2 is a schematic block diagram of a motor module control method in an embodiment of the present invention;

FIG. 3 is a schematic block diagram of a motor module control method in another embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a partial structure of an optical-electrical encoder according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another part of the optical-electrical encoder according to an embodiment of the present invention;

FIG. 6 is a schematic plane structure diagram of a code wheel in an embodiment of the invention;

FIG. 7 is a waveform diagram of a detection signal when the code wheel rotates clockwise in an embodiment of the present invention;

FIG. 8 is a schematic diagram showing waveforms of detection signals when the code wheel rotates counterclockwise in an embodiment of the present invention;

FIG. 9 is a schematic diagram of a ranging apparatus according to an embodiment of the invention;

FIG. 10 shows a schematic view of a distance measuring device in an embodiment of the invention;

fig. 11 shows a schematic diagram of the control of the first motor and the second motor in an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely a subset of embodiments of the invention and not all embodiments of the invention, with the understanding that the invention is not limited to the example embodiments described herein. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the invention described herein without inventive step, shall fall within the scope of protection of the invention.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present invention, a detailed structure will be set forth in the following description in order to explain the present invention. Alternative embodiments of the invention are described in detail below, however, the invention may be practiced in other embodiments that depart from these specific details.

In practical applications, asynchronous fluctuation always exists in motor rotation speed control, and the angle difference between two motors is changed more and more under the accumulation of time, so that the accuracy of the distance measuring device in measuring a detected object is affected, in order to solve the above problems, a first aspect of the invention provides a motor module control method, wherein a motor module comprises a first motor and a second motor, as shown in fig. 1, the motor module control method of the embodiment of the invention comprises the following steps:

step S101: the motor module comprises a first motor and a second motor, and rotating speed set values are input to the first motor and the second motor;

step S102: acquiring a phase relation between the first motor and the second motor in a motor rotation process;

step S103: and correcting the speed and/or position of the first motor and/or the second motor through the phase relationship of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the rotating speed set value and the target phase relationship.

In the control method of the embodiment of the invention, after the phase relationship between the first motor and the second motor is obtained in the rotating process of the first motor and the second motor, the speed and/or the position of the first motor and/or the second motor is/are corrected through the phase relationship between the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the set rotating speed value and the target phase relationship, thereby more effectively and accurately controlling the rotation of the first motor and the second motor,

and then improve the accuracy that the range unit measured to the detected object.

In the following, the motor module control method according to the embodiment of the present invention is described in detail with reference to the drawings, and features in the embodiments and implementations may be combined with each other without conflict.

First, in step S101, the rotation speed set value is a desired rotation speed of the first motor and the second motor, and the first motor and the second motor are rotated at the rotation speed set value.

In step S102, the rotation speed control of the first motor and the second motor always has asynchronous fluctuation during rotation, the angular difference between the two motors changes more and more with the accumulation of time, and the phases of the first motor and the second motor are out of the set position relationship. In this step, it is necessary to acquire the phase relationship between the first motor and the second motor during rotation of the motor.

Wherein the phase relationship of the first motor and the second motor comprises a phase difference of the first motor and the second motor, or the phase relationship of the first motor and the second motor comprises a phase sum of the first motor and the second motor. Specifically, in an example of the present invention, for example, when the initial phases of the first motor and the second motor are both zero positions, the phase difference between the first motor and the second motor is specifically a phase difference between the zero position of the first motor and the zero position of the second motor.

In an example of the present invention, the first motor and the second motor are used as a drive to rotate an optical element for changing a propagation path of a light beam, wherein the optical element can change the propagation path of the light beam by reflecting, refracting, diffracting, etc. the optical element will be explained and explained in further detail later, for example, the optical element includes at least a first optical element and a second optical element, wherein the first motor and the second motor are arranged side by side along the light path, the first motor is used to rotate the first optical element, the second motor is used to rotate the second optical element, and the first motor and the first optical element rotate synchronously. That is, the first motor and the first optical element are always kept relatively stationary, and similarly, the second motor and the second optical element rotate synchronously.

Acquiring a phase relationship between the first motor and the second motor during rotation of the motor, including:

acquiring an actual phase of the first motor;

acquiring an actual phase of the second motor;

and calculating the phase relation between the first motor and the second motor according to the actual phase of the first motor and the actual phase of the second motor.

Specifically, in an example of the present invention, the actual phase of the first motor is obtained by a rotation angle of a null position of a photoelectric encoder of the first motor, and for better explanation of a method for obtaining the actual phase of the first motor, the photoelectric encoder is further described below.

Referring to fig. 4 and 5, the photoelectric encoder 10 includes a code wheel 12, a detecting member 14, and a processor (not shown). The processor is connected to the detector 14. The code wheel 12 is mounted on the rotary object, and the code wheel 12 rotates along with the rotation of the rotary object. It will be appreciated that in this embodiment, the rotary mass and the code wheel 12 are relatively stationary. Therefore, the rotation parameter of the rotating object can be detected by using the code wheel 12. The rotation parameters include a direction of rotation, a rotation angle, and/or a rotation speed.

In the example of fig. 4 and 5, the rotating object is an optical element 32, and the optical element 32 is disposed inside the lens barrel 31. The lens barrel 31 is provided with a latch 312, the code wheel 12 is opened with a latch groove 126, and the latch 312 is at least partially latched in the latch groove 126 to mount the code wheel 12 on the lens barrel 31. In this way, the relative positions of the code wheel 12 and the optical element 32 are unchanged, and during the rotation process, the code wheel 12 and the optical element 32 are kept relatively static, and the code wheel 12 and the optical element 32 rotate synchronously, so that the rotation parameters of the optical element 32 can be detected through the code wheel 12.

Referring to fig. 6, in the present application, the code wheel 12 is divided into N detection regions 120 having equal widths along a circumferential direction X of the code wheel 12, and each detection region 120 includes one detected portion 122 and one code wheel portion 124. The detected portions 122 and the code wheel portions 124 are alternately distributed. That is, the code wheel 12 is provided with N detected portions 122 and N code wheel portions 124 in the circumferential direction X of the code wheel 12. The N detected parts 122 include N-K first detected parts 1222 and K second detected parts 1224, and the N code wheel parts 124 include N-K first code wheel parts 1242 and K second code wheel parts 1244. N is an integer greater than 2, K is an integer and is greater than or equal to 1 and less than N. The width of the first detected portion 1222 is different from the width of the second detected portion 1224 in the circumferential direction X of the code wheel 12. In fig. 6, the code wheel is circular.

It will be appreciated that the width of each detection region 120 is equal along the circumferential direction X of the code wheel 12. The detection area or areas 120 include a first detected portion 1222 and a first code wheel portion 1242, and the detection area or areas 120 include a second detected portion 1224 and a second code wheel portion 1244. For the detection area 120, the width of the first detected part 1222 plus the width of the first code wheel part 1242 is equal to the width of the second detected part 1224 plus the width of the second code wheel part 1244.

Specifically, in the illustrated embodiment, the width of the first detected portion 1222 is smaller than the width of the second detected portion 1224, and the width of the first code wheel portion 1242 is larger than the width of the second code wheel portion 1244 in the circumferential direction X of the code wheel 12. In one embodiment, in the circumferential direction X of the code wheel 12, the width of the first detected portion 1222 is equal to the width of the second code wheel portion 1244, the width of the second detected portion 1224 is equal to the width of the first code wheel portion 1242, and the width of the second detected portion 1224 is 3 times the width of the first detected portion 1222, that is, the width of the second detected portion 1224: the width of the first detected portion 1222 is 3: 1. of course, the width of the second object to be examined 1224 and the width of the first object to be examined 1222 are in a multiple relation, and may be 2 times or other multiples, and is not limited to 3 times.

In the present embodiment, the width refers to a circumferential X width (angle) of the code wheel 12 on the circumference. The number of detection regions 120 may be determined according to the size of the code wheel 12, the detection accuracy, the data processing amount of the processor, and the like. The number N of detection regions 120 may be equal to an equal number of 360 °, for example, 18, 36, or 72. Preferably, in consideration of the fact that the size of the code wheel 12 is not excessively large, the processor load is not increased, and the accuracy requirement can be satisfied, the number N of the detection regions 120 provided on the code wheel 12 is 36, that is, the width of each detection region 120 is 10 °. The number of the first detected part 1222 and the second detected part 1224 may be set as required. Preferably, the number of the second detected parts 1224 is set to 1, that is, K is 1, and the number of the first detected parts 1222 is 35. It will be appreciated that the width may be expressed in other units of value, such as millimeters.

For convenience of understanding, the code wheel 12 including 35 first detected

portions

1222 and 1 second detected portion 1224, 35 first code wheel portions 1242 and 1 second code wheel portion 1244 will be described below as an example. In the circumferential direction X of the code wheel 12, the width of the first detected portion 1222 is equal to the width of the second code wheel portion 1244, the width of the second detected portion 1224 is equal to the width of the first code wheel portion 1242, and the width of the second detected portion 1224 is 3 times the width of the first detected portion 1222.

In the present application, the detecting member 14 is provided on the circumference of the code wheel 12 for detecting the first detected portion 1222 and the second detected portion 1224. Since the width of the first detected part 1222 is different from the width of the second detected part 1224, the detection signal detected by the detecting member 14 varies with one rotation of the code wheel 12. Therefore, in the present application, the rotation parameter of the rotating object can be obtained by outputting the detection signal by one detecting member 14.

In some embodiments, the detected part 122 includes a through hole, a magnetic member, a light-transmitting member, or a light-reflecting member. When the detected part 122 is a through hole, a light-transmitting member or a light-reflecting member, the detecting member 14 correspondingly includes a photoelectric switch. When the detected portion 122 is a reflector, the reflectivity of the reflector is greater than that of the chuck segment 124. When the detected part 122 is a magnetic member, correspondingly, the detecting member 14 includes a hall element. Preferably, the detected portion 122 is a through hole, and the detecting member 14 includes a photoelectric switch. The detected portion 122 can transmit light, and the code wheel portion 124 cannot transmit light.

The optoelectronic switch may be a slot type optoelectronic switch (i.e. a correlation type optoelectronic switch), which includes a base (not shown), a transmitting tube (not shown) and a receiving tube (not shown). Wherein, the launching tube and the receiving tube are respectively arranged on the base at intervals. The transmitting tube and the receiving tube are symmetrically arranged on two sides of the code wheel 12, and the centers of the transmitting tube and the receiving tube are located on the circumference of the detected part 122 and the code wheel part 124, so that the transmitting tube and the receiving tube are matched with the detected part 122 and the code wheel part 124. The base is provided at a predetermined interval on the outer circumference of the code wheel 12, thereby preventing the outer circumferential surface of the code wheel 12 from colliding with the base when the code wheel 12 is rotated. Of course, the opto-electronic switch may also be a reflective opto-electronic switch.

In the process that the rotary object drives the coded disc 12 to rotate, the photoelectric switch is static, a transmitting tube of the photoelectric switch transmits light signals, when the detected part 122 rotates to a position between the transmitting tube and the receiving tube, when the detected part 122 is a through hole or a light-transmitting piece, the receiving tube can receive the light signals transmitted by the transmitting tube, when the coded disc part 124 rotates to a position between the transmitting tube and the receiving tube, the receiving tube cannot receive the light signals transmitted by the transmitting tube, and therefore when the detected part 122 and the coded disc part 124 of the coded disc 12 rotate to the position of the photoelectric switch, the photoelectric switch outputs different level signals respectively.

In one embodiment, when the detected part 122 moves to the detecting element 14 (photoelectric switch), the detecting signal output by the detecting element 14 is the first signal, and when the code wheel part 124 moves to the detecting element 14, the detecting signal output by the detecting element 14 is the second signal. The first signal is different from the second signal. Since the detected portions 122 and the code wheel portions 124 are alternately distributed, the detection signal is the alternating first signal and second signal. In the present embodiment, the width of the first detected portion 1222 is smaller than the width of the second detected portion 1224 in the circumferential direction X of the code wheel 12. Therefore, the length of the first signal corresponding to the first detected part 1222 is smaller than the length of the first signal corresponding to the second detected part 1224.

The first signal may be a low level signal and the second signal may be a high level signal. For example, the low level signal is a signal having a level of 0, and the high level signal is a signal having a level of 1. The detection signal can be a sine wave signal, a cosine wave signal or a triangular wave signal. Preferably, the detection signal is a square wave signal.

Referring to fig. 7 and 8, the rotating object rotates to rotate the code wheel 12. The code wheel 12 rotates once, that is, in one rotation period, the detecting member 14 can detect a first signal and a second signal which are the same in length and continuous. When the rotation is clockwise, the first signal is detected in the first signal and the second signal which are continuous and have the same length. When rotating counterclockwise, the second signal is detected first in the continuous first signal and the second signal with the same length. In this way, the rotation direction of the rotating object can be detected based on the waveform of the detection signal of fig. 7 or 8 in one rotation cycle.

In an example of the present invention, the first motor and the second motor are arranged side by side along an optical path, and the first motor and the second motor are respectively and fixedly connected with the first photoelectric encoder and the second photoelectric encoder, the first motor and the second motor respectively have hollow parts for respectively accommodating one of the first optical element and the second optical element, the relative positions between the first motor, the first optical element and the first photoelectric encoder are not changed, and during rotation, the code wheel, the first motor and the first optical element are kept relatively stationary and synchronously rotate, so that the rotation parameters of the first motor and the first optical element can be detected through the code wheel. The rotation parameters include a rotation angle and a rotation speed.

Similarly, in the same way, the actual phase of the second motor is obtained through the rotation angle of the zero position of the second photoelectric encoder of the second motor.

After the actual phase of the first motor and the actual phase of the second motor are obtained, the phase relationship between the first motor and the second motor is calculated according to the actual phase relationship of the two. The difference in the rotation angle between the first motor and the second motor is obtained, for example, by calculating the difference between the actual phase of the first motor and the actual phase of the second motor.

In another example of the present invention, in order to improve the accuracy and reliability of the phase relationship between the first motor and the second motor, the method further comprises the step of performing a fusion calculation of the actual phases of the first motor and the second motor, by which the accuracy of the actual phases of the first motor and the second motor is further improved.

In an example of the present invention, the method further includes:

theoretical phases of the first motor and the second motor are theoretically calculated through an algorithm, in one example of the invention, voltage and current information of the first motor and the second motor is respectively obtained through a voltage-current sensor, and then the theoretical phases of the first motor and the second motor are respectively calculated through the voltage and current information of the first motor and the second motor.

After theoretical phases of the first motor and the second motor are obtained, Fusion calculation (Position sensor Fusion Algorithm) is performed on the actual phases and the theoretical phases of the first motor and the second motor to obtain the phases of the first motor and the second motor, and accuracy of the phases of the first motor and the second motor is further improved through the Fusion calculation.

And finally, calculating the phase relation between the first motor and the second motor according to the phase of the first motor and the phase of the second motor which are obtained through fusion calculation.

Whether the method is subjected to fusion calculation or not can be selected according to the requirements on precision and reliability in practical application.

In step S103, the speed and/or position of the first motor and/or the second motor is corrected according to the phase relationship between the first motor and the second motor in step S102 in step S101, and the first motor and the second motor are controlled to rotate according to the rotation speed set value and the target phase relationship.

In this step, the target phase relationship of the first motor and the second motor means to rotate while maintaining a specific phase relationship when the rotation speed control of the first motor and the second motor eliminates asynchronous fluctuations during rotation, for example, the phase relationship of the first motor and the second motor includes a sum of phases of the first motor and the second motor, or the target phase relationship includes a sum of target phases of the first motor and the second motor.

In an example of the present invention, for example, when the initial phases of the first motor and the second motor are both zero positions, the target phase difference between the zero position of the first motor and the zero position of the second motor is specifically a target phase difference between the zero positions of the first motor and the second motor.

In another example of the present invention, the phase relationship between the first motor and the second motor may be a fixed value, for example, the target phase sum between the zero positions of the first motor and the second motor is pi, or the target phase difference is a positive value, which may be any selected value, and is not limited herein.

In an example of the present invention, the first motor and the second motor have the same zero position, that is, the first optical element and the second optical element have the same zero position, and the target phase relationship includes: the target phase sum between the zero position of the first optical element and the zero position of the second optical element is pi, or the target phase difference is a positive value.

In the embodiment of the present invention, the first motor may be corrected individually according to the phase relationship between the first motor and the second motor, the second motor may also be corrected individually, or the first motor and the second motor may also be corrected and controlled simultaneously, which may be selected according to actual needs.

Further, the position correction may be performed on the first motor, the speed correction may be performed on the first motor, the position and the speed may be simultaneously corrected, and similarly, the position correction may be performed on the second motor, the speed correction may be performed on the second motor, and the position and the speed may be simultaneously corrected.

In an example of the present invention, the control method includes: acquiring a phase compensation value; and correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor.

The phase compensation value is used for correcting the phase difference between the zero position of the load element of the first motor and the zero position of the photoelectric encoder, and/or is used for correcting the phase difference between the zero position of the load element of the second motor and the corresponding zero position of the photoelectric encoder.

For example, in an example of the present invention, the first motor-loaded element is a first optical element, where a zero position of the first optical element ideally coincides with a zero position of a photoelectric encoder on the first optical element, but due to a machining error or the fact that the zero position of the first optical element does not coincide with the zero position of the photoelectric encoder on the first optical element when installed or designed, in this case, in order to synchronize the first motor-loaded element with the zero position of the photoelectric encoder, and further obtain a phase of the first motor-loaded element more accurately, a correction needs to be performed for this, and similarly, the zero position of the second motor-loaded element and the zero position of the corresponding photoelectric encoder also need to be corrected.

In an example of the present invention, the phase compensation value may be a specific value calculated after obtaining a phase difference between the zero position of the load element of the first motor and the zero position of the photoelectric encoder and a phase difference between the zero position of the load element of the second motor and the corresponding zero position of the photoelectric encoder.

The methods for controlling the position and the speed are described below with reference to the drawings.

In an example of the speed control, as shown in fig. 2, after the phase relationship is obtained in step S102, the rotational speed reference value is directly output to a control module according to the phase relationship, where the control module may be a Multi-Mode Controller (Multi Mode Controller), and the control Mode may be flexibly selected according to different control purposes. In the case where the control is performed for the purpose of accurately controlling the motor rotation speed, a command value of the torque current may be obtained by an asr (automatic regulator) control loop described below; when the control purpose is precise positioning, an APR (auto Position regulator) control loop can be used to obtain the command value of the torque current; more complex applications require a combination of these two controls or other means to obtain the commanded value for torque current.

In an example of the present invention, when the control module selects to control the rotation speed of the motor, the command value of the torque current may be obtained through an asr (automatic speed regulator) control loop.

Further, an effective way to improve the efficiency of the Motor is to adopt a high-efficiency energy-saving Motor and a Motor control system, wherein the Motor mainly comprises a direct current Motor (DCMotor-DCM for short), an induction Motor (induction Motor-IM for short), a Permanent Magnet Motor (PMM for short) and a Switched Reluctance Motor (SRM for short). The permanent Magnet Motor comprises two major types of direct current Brushless (Brushless DC Motor-BLDC for short) and permanent Magnet Synchronous (PMSM for short).

The motor control theory comprises a plurality of theories, wherein space vector regulation (SVM) belongs to the control theory with excellent comprehensive performances such as control precision, efficiency and the like in a permanent magnet synchronous motor and magnetic field orientation (vector) control (FOC) in a direct current brushless motor control system. In one example of the present invention, a field oriented (vector) control (FOC) is selected to control the rotation speed of the first motor and/or the second motor in a dc brushless motor control system to ensure that the first motor and/or the second motor rotates at the rotation speed set value and a target phase relationship.

In the example of position control, as shown in fig. 3, in the method for controlling the position, since a set rotation speed value is input, it is necessary to switch between the rotation speed and the position and convert the rotation speed into the position, for example, in an example of the present invention, in the step S101 or in the step S103, after the set rotation speed value is input to the first motor and the second motor, a step of performing integral conversion on the rotation speed is added to obtain the position information of the first motor and the second motor.

After the phase relationship is obtained in step S102, the position reference value is directly output to a control module according to the phase relationship, where the control module may be a Multi-Mode Controller (Multi Mode Controller), and the control Mode may be flexibly selected according to different control purposes. In the case where the control is performed for the purpose of accurately controlling the motor rotation speed, a command value of the torque current may be obtained by an asr (automatic regulator) control loop described below; when the control purpose is precise positioning, an APR (auto Position regulator) control loop can be used to obtain the command value of the torque current; more complex applications require a combination of these two controls or other means to obtain the commanded value for torque current.

In an example of the present invention, the control module obtains a command value of the torque current through an apr (auto Position regulator) control loop when the control purpose is the precise positioning. When the motor rotation speed is to be controlled, a command value of the torque current can be obtained by an asr (automatic speed regulator) control loop.

The motor control theory comprises a plurality of theories, wherein space vector regulation (SVM) belongs to the control theory with excellent comprehensive performances such as control precision, efficiency and the like in a permanent magnet synchronous motor and magnetic field orientation (vector) control (FOC) in a direct current brushless motor control system.

In one example of the present invention, a field oriented (vector) control (FOC) is selected to control the rotation speed of the first motor and/or the second motor in a dc brushless motor control system to ensure that the first motor and/or the second motor rotates at the rotation speed set value and a target phase relationship.

The method of correcting the speed of the first motor and/or the second motor in the two methods described above adjusts the frequency higher than the method based on position correction, and the angular synchronization accuracy is higher for specifying the respective speeds of the first motor and the second motor phase.

In an embodiment of the present invention, the first motor and the second motor are alternately controlled by the same controller in time division, and different motors are controlled at different times. Specifically, as shown in fig. 11, in two adjacent control periods: in a first control period, the first motor is controlled by the controller, and the second motor maintains the control state in the last control period; in a second control period, the second motor is controlled by the controller, and the first motor maintains a control state in the first control period.

In an example of the present invention, the code wheel signal of the first photoelectric encoder of the first motor is used for acquiring the phase of the first motor, the chip is used for acquiring the phase of the first motor, and similarly, the code wheel signal of the second photoelectric encoder of the second motor is used for acquiring the phase of the second motor, and the code wheel signal of the first photoelectric encoder acquired by the chip and the code wheel signal of the second photoelectric encoder acquired by the chip are captured in an interruption manner as described above because the first motor and the second motor are time-sharing alternative control.

In the invention, the first motor and the second motor are controlled by the same controller, so that the real-time performance of photoelectric encoder coded disc signals can be ensured to be higher, the photoelectric coded disc signals of the first motor and the second motor are captured and processed in an interruption mode, and the actual phase acquisition and synchronous processing of the first motor and the second motor can realize zero time delay, thereby improving the synchronous control precision of double motors.

Further, the first motor and the second motor are each individually controlled by separate 3-way complementary PWM switching signals, e.g., in one example of the invention, the first motor and the second motor are each controlled by complementary pulse width modulated PWM signals.

Specifically, in one example of the present invention, in a first control period, a duty ratio of a PMW signal of a first motor is calculated according to the acquired speed and/or position of the first motor, and rotation of the first motor is controlled according to a signal of the duty ratio of the PMW signal, wherein in a second control period, the duty ratio of a PMW signal of a second motor is calculated according to the acquired speed and/or position of the second motor, and rotation of the second motor is controlled according to a signal of the duty ratio of the PMW signal, at which time, the duty ratio of the PMW signal of the first motor is maintained the same as the PMW signal of the first motor in the first control period, that is, the first motor maintains a rotation state in the first control period. And then, in the next first control period, the speed and/or the position of the first motor are acquired again according to the rotation conditions of the first motor and the second motor, the duty ratio of the PMW signal of the first motor is calculated again, the rotation of the first motor is controlled according to the recalculated PMW signal, in the next second control period, the speed and/or the position of the second motor are acquired again according to the rotation conditions of the first motor and the second motor, the duty ratio of the PMW signal of the second motor is calculated again, the rotation of the second motor is controlled according to the recalculated PMW signal, and at the moment, the first motor still maintains the rotation state under the control of the recalculated PMW signal in the second first period. The first motor and the second motor are controlled in a cyclic alternating mode in the mode.

Furthermore, the control and actual phase signal acquisition of the first motor and the second motor are carried out in the same chip, and the actual phase information acquisition and synchronous processing of the first motor and the second motor can realize zero time delay.

In an example of the present invention, the chip may be a Micro Control Unit (MCU) chip, but is not limited to this example.

In summary, after the phase relationship between the first motor and the second motor is obtained during the rotation of the first motor and the second motor, the speed and/or the position of the first motor and/or the second motor is corrected according to the phase relationship between the first motor and the second motor, so as to ensure that the first motor and the second motor rotate at the set rotation speed value and the target phase relationship, thereby more effectively and accurately controlling the rotation of the first motor and the second motor,

In the above example, the control method in the motor module is described in detail, specifically, the case that the motor module includes the first motor and the second motor is described, it should be noted that the number of the motors in the motor module is not limited to a certain numerical range, for example, the motor module may further include a third motor, where the third motor drives a third optical element to rotate.

Wherein the first, second, and third Optical elements comprise lenses, mirrors, prisms, galvanometers, gratings, liquid crystals, Optical Phased arrays (Optical Phased arrays), or any combination thereof.

Optionally, the third optical element comprises a pair of opposed non-parallel surfaces through which the light beam passes. In one embodiment, the third optical element comprises a prism having a thickness that varies along at least one radial direction. In one embodiment, the third optical element comprises a wedge angle prism. At least two of the first, second and third optical elements rotate at different rotational speeds and/or rotational directions.

Further, the types of the first, second, and third optical elements are not limited to the above examples, and may be selected according to actual needs.

The following is a detailed description of the case where the first motor and the second motor in the motor module drive the first optical element and the second optical element when applied to a scanning module and a laser radar. In the explanation and explanation of the following embodiments, the corresponding steps and the related explanation and explanation of the above embodiments can be referred to without contradiction to the description of the above embodiments, and the description will not be repeated here.

In a second aspect of the present invention, there is provided a scanning module control method, the scanning module including a motor module and an optical element module;

the motor module comprises a first motor and a second motor, the optical element module comprises a first optical element and a second optical element, the first motor is used for driving the first optical element to rotate, and the second motor is used for driving the second optical element to rotate.

In the scanning module, the first motor and the second motor are controlled to be in a complete constant speed reverse direction, so that specific optical track scanning is realized, asynchronous fluctuation always exists in motor rotating speed control in practical application, angle difference of the two motors changes more and more under time accumulation, scanning tracks change, point cloud gaps output by the distance measuring device change, distribution uniformity of point cloud points is poor, partial point cloud gaps exceed a tolerance range, and accuracy of the distance measuring device in measuring a detected object is affected.

In order to solve the problem, the scanning module provided by the invention controls the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate through the motor module control party, so as to ensure that the first optical element and the second optical element rotate according to the rotating speed set value and the target phase relationship.

In one embodiment, as shown in FIG. 10, the scanning module 202 may include at least one optical element for changing the propagation path of the light beam, wherein the optical element may change the propagation path of the light beam by reflecting, refracting, diffracting, etc. the optical element includes at least one light refracting element having non-parallel exit and entrance faces, for example. For example, the scanning module 202 includes a lens, mirror, prism, galvanometer, grating, liquid crystal, Optical Phased Array (Optical Phased Array), or any combination thereof. In one example, at least a portion of the optical element is moved, for example, by a driving module, and the moved optical element can reflect, refract, or diffract the light beam to different directions at different times. In some embodiments, multiple optical elements of the scanning module 202 may rotate or oscillate about a common axis 209, with each rotating or oscillating optical element serving to constantly change the direction of propagation of an incident beam. In one embodiment, the multiple optical elements of the scanning module 202 may rotate at different rotational speeds or oscillate at different speeds. In another embodiment, at least some of the optical elements of the scanning module 202 may rotate at substantially the same rotational speed. In some embodiments, the multiple optical elements of the scanning module may also be rotated about different axes. In some embodiments, the multiple optical elements of the scanning module may also rotate in the same direction, or in different directions; or in the same direction, or in different directions, without limitation.

In one embodiment, the scanning module 202 includes a first optical element 214 and a driver 216, such as a first motor, coupled to the first optical element 214, the driver 216 for driving the first optical element 214 to rotate about the rotation axis 209, causing the first optical element 214 to change the direction of the collimated light beam 219. The first optical element 214 projects the collimated beam 219 into different directions. In one embodiment, the angle between the direction of the collimated beam 219 after it is altered by the first optical element and the axis of rotation 209 changes as the first optical element 214 is rotated. In one embodiment, the first optical element 214 includes a pair of opposing non-parallel surfaces through which the collimated light beam 219 passes. In one embodiment, the first optical element 214 includes a prism having a thickness that varies along at least one radial direction. In one embodiment, the first optical element 214 comprises a wedge angle prism that refracts the collimated beam 219.

In one embodiment, the scanning module 202 further comprises a second optical element 215, the second optical element 215 rotating around a rotation axis 209, the rotation speed of the second optical element 215 being different from the rotation speed of the first optical element 214. The second optical element 215 is used to change the direction of the light beam projected by the first optical element 214. In one embodiment, second optical element 215 is coupled to another driver 217 (e.g., a second motor), and driver 217 rotates second optical element 215. The first optical element 214 and the second optical element 215 may be driven by the same or different drivers, such that the first optical element 214 and the second optical element 215 rotate at different speeds and/or turns, thereby projecting the collimated light beam 219 into different directions in the ambient space, which may scan a larger spatial range. In one embodiment, the controller 218 controls the

drivers

216 and 217 to drive the first optical element 214 and the second optical element 215, respectively. The rotation speed of the first optical element 214 and the second optical element 215 can be determined according to the region and the pattern expected to be scanned in the actual application. The

drives

216 and 217 may include motors or other drives.

In one example, the driver 216 and the driver 217 may have opposite rotation directions to respectively drive the first optical element 214 and the second optical element 215 to rotate in opposite rotation directions, or the driver 216 and the driver 217 may have the same rotation direction to respectively drive the first optical element 214 and the second optical element 215 to rotate in the same rotation direction, which is set according to practical requirements.

In one embodiment, second optical element 215 includes a pair of opposing non-parallel surfaces through which the light beam passes. In one embodiment, second optical element 215 includes a prism having a thickness that varies along at least one radial direction. In one embodiment, second optical element 215 comprises a wedge angle prism.

In one embodiment, the scan module 202 further comprises a third optical element (not shown) and a driver for driving the third optical element to move. Optionally, the third optical element comprises a pair of opposed non-parallel surfaces through which the light beam passes. In one embodiment, the third optical element comprises a prism having a thickness that varies along at least one radial direction. In one embodiment, the third Optical element comprises one of a wedge prism, a flat mirror, a lens, a mirror, a galvanometer, a grating, a liquid crystal, an Optical Phased Array (Optical Phased Array), or any combination thereof. In one example, the rotational speed of the third optical element is different from the rotational speed of the first/second optical element and/or the turning of the third optical element is different from the turning of the first/second optical element.

In one embodiment, the scanning module comprises 2 or 3 photorefractive elements arranged in sequence on an outgoing light path of the optical pulse sequence. Optionally, at least 2 of the photorefractive elements in the scanning module rotate during scanning to change the direction of the sequence of light pulses.

The scanning module has different scanning paths at least partially different times, and the rotation of each optical element in the scanning module 202 may project light in different directions, such as the direction of the projected light 211 and the direction 213, so as to scan the space around the distance measuring device 200. When the light 211 projected by the scanning module 202 hits the detection object 201, a part of the light is reflected by the detection object 201 to the distance measuring device 200 in the opposite direction to the projected light 211. The return light 212 reflected by the object 201 passes through the scanning module 202 and then enters the collimating element 204.

The motor module in the scanning module may be controlled by referring to the control method in the above embodiment to ensure that the first optical element and the second optical element rotate according to the rotation speed set value and the target phase relationship, which is not described herein again.

In this embodiment, the first optical element and the second optical element are each phase-measured by a respective photoelectric encoder, and the first motor and the first optical element and the first photoelectric encoder are relatively stationary, so that the zero position of the code wheel of the first photoelectric encoder is equal to the zero position of the first motor and the zero position of the first optical element, and similarly, the zero position of the code wheel of the second photoelectric encoder is equal to the zero position of the second motor and the zero position of the second optical element.

When the first optical element and/or the second optical element is a prism, the null position may refer to the thinnest or thickest position.

The phase refers to an angle and a direction of rotation of the first optical element and the second optical element, for example, if the first rotation direction is set to be positive, and if the angle of rotation in the first direction is positive, the reverse rotation in the first direction is negative, where the angle of rotation refers to setting a virtual reference line during rotation, and the angle of rotation refers to an angle of rotation of a null position of the first optical element and the second optical element or a null position of the code wheel with respect to the reference line.

In an example of the present invention, in a front view of the code wheel rotation track, the zero position rotation track of the code wheel is a circumferential surface, a horizontal straight line passing through a center of a circle on the circumferential surface is taken as a reference line, and a phase may be defined as an included angle between a connecting line between the zero position and the center of the circle of the code wheel and the reference line, for example, if the counterclockwise rotation of the code wheel is defined as a positive value of the phase, the included angle is a positive value, and if the code wheel rotates clockwise, the phase is a negative value, and the included angle is a negative value.

Wherein the target phase relationship comprises that the target phase sum of the first optical element and the second optical element is kept fixed, in particular pi or zero, namely the first optical element and the second optical element keep a constant and reverse rotation state.

The target phase relationship includes that the target phase difference of the first optical element and the second optical element is kept fixed, for example, the target phase difference of the first optical element and the second optical element is a positive value, which can be any value, and the phase difference means that the first optical element and the second optical element synchronously rotate in the same direction and at the same speed.

A third aspect of the present invention provides a method for controlling a distance measuring device, where the distance measuring device of a laser distance measuring system is a sensing system that uses laser to perform scanning and distance measurement to obtain three-dimensional information in a surrounding scene. The basic principle is that laser pulses are actively transmitted to a detected object, laser echo signals are captured, and the distance of the detected object is calculated according to the time difference between the transmission and the reception of the laser; obtaining angle information of the measured object based on the known emission direction of the laser; by high-frequency transmission and reception, the distance and angle information of massive detection points can be acquired.

The following describes the composition and control method of the distance measuring device in detail with reference to the accompanying drawings. The structure of a distance measuring device in an embodiment of the present invention, which includes a laser radar, is exemplarily described in more detail with reference to fig. 9 and 10, and the distance measuring device is applicable to the present application as well as other suitable distance measuring devices.

The scheme provided by each embodiment of the invention can be applied to a distance measuring device, and the distance measuring device can be electronic equipment such as a laser radar, laser distance measuring equipment and the like. In one embodiment, the ranging device is used to sense external environmental information, such as distance information, orientation information, reflected intensity information, velocity information, etc. of environmental targets. In one implementation, the ranging device may detect the distance of the probe to the ranging device by measuring the Time of Flight (TOF), which is the Time-of-Flight Time, of light traveling between the ranging device and the probe. Alternatively, the distance measuring device may detect the distance from the probe to the distance measuring device by other techniques, such as a distance measuring method based on phase shift (phase shift) measurement or a distance measuring method based on frequency shift (frequency shift) measurement, which is not limited herein.

For ease of understanding, the following describes an example of the ranging operation with reference to the ranging apparatus 100 shown in fig. 9.

Illustratively, the distance measuring device may include a transmitting module, a receiving module and a temperature control system, wherein the transmitting module is used for emitting light pulses; the receiving module is used for receiving at least part of the light pulse reflected by the object and determining the distance of the object relative to the distance measuring device according to the received at least part of the light pulse.

Specifically, as shown in fig. 9, the transmission module includes a transmission circuit 110; the receiving module includes a receiving circuit 120, a sampling circuit 130, and an arithmetic circuit 140.

The transmit circuit 110 may emit a train of light pulses (e.g., a train of laser pulses). The receiving circuit 120 may receive the optical pulse train reflected by the detected object, perform photoelectric conversion on the optical pulse train to obtain an electrical signal, process the electrical signal, and output the electrical signal to the sampling circuit 130. The sampling circuit 130 may sample the electrical signal to obtain a sampling result. The arithmetic circuit 140 may determine the distance between the distance measuring device 100 and the detected object based on the sampling result of the sampling circuit 130.

Optionally, the distance measuring apparatus 100 may further include a control circuit 150, and the control circuit 150 may implement control of other circuits, for example, may control an operating time of each circuit and/or perform parameter setting on each circuit, and the like.

It should be understood that, although the distance measuring device shown in fig. 9 includes a transmitting circuit, a receiving circuit, a sampling circuit and an arithmetic circuit for emitting a light beam to detect, the embodiments of the present application are not limited thereto, and the number of any one of the transmitting circuit, the receiving circuit, the sampling circuit and the arithmetic circuit may be at least two, and the at least two light beams are emitted in the same direction or in different directions respectively; the at least two light paths may be emitted simultaneously or at different times. In one example, the light emitting chips in the at least two transmitting circuits are packaged in the same module. For example, each transmitting circuit comprises a laser emitting chip, and die of the laser emitting chips in the at least two transmitting circuits are packaged together and accommodated in the same packaging space.

In some implementations, in addition to the circuit shown in fig. 9, the distance measuring apparatus 100 may further include a scanning module for emitting at least one light pulse sequence (e.g., a laser pulse sequence) emitted from the emitting circuit with a changed propagation direction so as to scan the field of view. Illustratively, the scan area of the scan module within the field of view of the ranging device increases over time.

Here, a module including the transmission circuit 110, the reception circuit 120, the sampling circuit 130, and the operation circuit 140, or a module including the transmission circuit 110, the reception circuit 120, the sampling circuit 130, the operation circuit 140, and the control circuit 150 may be referred to as a ranging module, which may be independent of other modules, for example, a scanning module.

The distance measuring device can adopt a coaxial light path, namely the light beam emitted by the distance measuring device and the reflected light beam share at least part of the light path in the distance measuring device. For example, at least one path of laser pulse sequence emitted by the emitting circuit is emitted by the scanning module after the propagation direction is changed, and the laser pulse sequence reflected by the detector is emitted to the receiving circuit after passing through the scanning module. Alternatively, the distance measuring device may also adopt an off-axis optical path, that is, the light beam emitted by the distance measuring device and the reflected light beam are transmitted along different optical paths in the distance measuring device. FIG. 10 shows a schematic diagram of one embodiment of a distance measuring device of the present invention employing coaxial optical paths.

The ranging apparatus 200 comprises a ranging module 210, the ranging module 210 comprising a light source, i.e. a transmitter 203 (which may comprise the transmitting circuitry described above), a collimating element 204, a detector 205 (which may comprise the receiving circuitry, sampling circuitry and arithmetic circuitry described above) and a path-altering element 206. The distance measuring module 210 is configured to emit a light beam, receive return light, and convert the return light into an electrical signal. Wherein the emitter 203 may be configured to emit a sequence of light pulses. In one embodiment, the transmitter 203 may emit a sequence of laser pulses. Optionally, the laser beam emitted by the emitter 203 is a narrow bandwidth beam having a wavelength outside the visible range. The collimating element 204 is disposed on an emitting light path of the emitter, and is configured to collimate the light beam emitted from the emitter 203, and collimate the light beam emitted from the emitter 203 into parallel light to be emitted to the scanning module. The collimating element is also for converging at least a portion of the return light reflected by the detector. The collimating element 204 may be a collimating lens or other element capable of collimating a light beam.

In the embodiment shown in fig. 10, the transmit and receive optical paths within the distance measuring device are combined by the optical path changing element 206 before the collimating element 204, so that the transmit and receive optical paths can share the same collimating element, making the optical path more compact. In other implementations, the emitter 203 and the detector 205 may use respective collimating elements, and the optical path changing element 206 may be disposed in the optical path after the collimating elements.

In the embodiment shown in fig. 10, since the beam aperture of the light beam emitted from the emitter 203 is small and the beam aperture of the return light received by the distance measuring device is large, the optical path changing element can adopt a small-area mirror to combine the emission optical path and the reception optical path. In other implementations, the optical path changing element may also be a mirror with a through hole, wherein the through hole is used for transmitting the outgoing light from the emitter 203, and the mirror is used for reflecting the return light to the detector 205. Therefore, the shielding of the bracket of the small reflector to the return light can be reduced in the case of adopting the small reflector.

In the embodiment shown in fig. 10, the optical path altering element is offset from the optical axis of the collimating element 204. In other implementations, the optical path altering element may also be located on the optical axis of the collimating element 204.

The distance measuring device 200 further comprises a scanning module 202, configured to change the light beams emitted by the light sources to different propagation directions in sequence and emit the light beams, so as to form a scanning field of view. The scanning module 202 is disposed on the emitting light path of the distance measuring module 210, and the scanning module 202 is configured to change the transmission direction of the collimated light beam 219 emitted by the collimating element 204, project the collimated light beam to the external environment, and project the return light beam to the collimating element 204. The return light is converged by the collimating element 204 onto the detector 205.

The scanning module 202 may refer to the description corresponding to the scanning module in the above embodiments, and is not described herein again.

The detector 205 is placed on the same side of the collimating element 204 as the emitter 203, and the detector 205 is used to convert at least part of the return light passing through the collimating element 204 into an electrical signal.

In one embodiment, each optical element is coated with an antireflection coating. Optionally, the thickness of the antireflection film is equal to or close to the wavelength of the light beam emitted by the emitter 203, which can increase the intensity of the transmitted light beam.

In one embodiment, a filter layer is coated on a surface of a component in the distance measuring device, which is located on the light beam propagation path, or a filter is arranged on the light beam propagation path, and is used for transmitting at least a wave band in which the light beam emitted by the emitter is located and reflecting other wave bands, so as to reduce noise brought to the receiver by ambient light.

In some embodiments, the transmitter 203 may include a laser diode through which laser pulses in the order of nanoseconds are emitted. Further, the laser pulse reception time may be determined, for example, by detecting the rising edge time and/or the falling edge time of the electrical signal pulse. In this manner, the ranging apparatus 200 may calculate TOF using the pulse reception time information and the pulse emission time information, thereby determining the distance of the probe 201 to the ranging apparatus 200. The distance and orientation detected by ranging device 200 may be used for remote sensing, obstacle avoidance, mapping, modeling, navigation, and the like.

Based on the application scenario, asynchronous fluctuation always exists in motor rotation speed control in practical application of the laser ranging system, and the angle difference of the two motors is changed more and more under the accumulation of time, so that the accuracy of the ranging device in measuring a detected object is influenced. Inputting a set rotating speed value to the first motor and the second motor; acquiring a phase relation between the first motor and the second motor in a motor rotation process; and correcting the speed and/or position of the first motor and/or the second motor through the phase relationship of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the rotating speed set value and the target phase relationship. The control method of the embodiment of the invention can ensure that the first motor and the second motor rotate according to the rotating speed set value and the target phase relation, thereby more effectively and accurately controlling the rotation of the first motor and the second motor,

inputting a set rotating speed value to the first motor and the second motor;

The motor module comprises the control module and is used for realizing the control method, namely correcting the speed and/or the position of the first motor and/or the second motor through the phase relation of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the set rotating speed value and the target phase relation. Thus, it also has the advantages of the control module and the control method described hereinbefore.

The structure of the motor module and the control mode of the control module can refer to the related explanations and descriptions of the foregoing embodiments of the present invention, and are not repeated herein.

A fifth aspect of the present invention provides a scanning module, which includes a motor module, an optical element module, and a control module; the motor module comprises a first motor and a second motor, the optical element module comprises a first optical element and a second optical element, the first motor is used for driving the first optical element to rotate, and the second motor is used for driving the second optical element to rotate;

the control module is used for: the motor module control party controls the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate, so as to ensure that the first optical element and the second optical element rotate according to the rotating speed set value and the target phase relationship.

The structure of the scanning module and the control manner of the control module can refer to the related explanations and descriptions of the foregoing embodiments of the present invention, and are not repeated herein. The scanning module of the embodiment of the present invention includes the foregoing control module and can be used to implement the foregoing control method, so that the scanning module also has the advantages of the foregoing control module and control method.

A sixth aspect of the present invention provides a ranging apparatus comprising:

a light source for emitting light pulses along an exit light path;

a control module, configured to control the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate through the scanning module control method described above, so as to ensure that the first optical element and the second optical element rotate with the set rotation speed value and the target phase relationship, where the first optical element and the second optical element that rotate are respectively located on the light pulse emitting path and configured to change a transmission direction of the light pulse;

In this embodiment, the structure of the scanning module in the ranging device and the control manner of the control module may refer to the related explanations and descriptions of the foregoing embodiments of the present invention, and are not repeated herein.

In summary, the distance measuring apparatus according to the embodiment of the present invention includes the control module and can be used to implement the control method described above, so that the distance measuring apparatus also has the advantages of the control apparatus and the control method described above.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the foregoing illustrative embodiments are merely exemplary and are not intended to limit the scope of the invention thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as set forth in the appended claims.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another device, or some features may be omitted, or not executed.

In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the invention and aiding in the understanding of one or more of the various inventive aspects. However, the method of the present invention should not be construed to reflect the intent: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

It will be understood by those skilled in the art that all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where such features are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, not others, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

The various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or Digital Signal Processor (DSP) may be used in practice to implement some or all of the functionality of some of the modules according to embodiments of the present invention. The present invention may also be embodied as apparatus programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present invention may be stored on computer-readable media or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

Claims

A motor module control method is characterized in that the motor module comprises a first motor and a second motor, and the control method comprises the following steps:

inputting a set rotating speed value to the first motor and the second motor;

acquiring a phase relation between the first motor and the second motor in a motor rotation process;

and correcting the speed and/or position of the first motor and/or the second motor through the phase relationship of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the rotating speed set value and the target phase relationship.
The motor module control method according to claim 1, wherein the phase relationship of the first motor and the second motor includes a phase difference of the first motor and the second motor, and the target phase relationship includes a target phase difference of the first motor and the second motor; alternatively, the first and second electrodes may be,

the phase relationship of the first motor and the second motor includes a phase sum of the first motor and the second motor, and the target phase relationship includes a target phase sum of the first motor and the second motor.
The motor speed control method according to claim 2, wherein the phase difference between the first motor and the second motor is specifically a phase difference between a zero position of the first motor and a zero position of the second motor;

the target phase difference between the first motor and the second motor is specifically a target phase difference between a zero position of the first motor and a zero position of the second motor.
The method according to claim 2 or 3, wherein the first motor and the second motor are arranged side by side along the optical path, the first motor is used for driving the first optical element to rotate, the second motor is used for driving the second optical element to rotate, and the first optical element and the second optical element have the same zero position;

the target phase relationship includes: the target phase sum between the null of the first optical element and the null of the second optical element is a fixed value, or the target phase difference is a fixed value.
The motor speed control method according to claim 4, wherein the target phase relationship includes: the target phase sum between the zero position of the first optical element and the zero position of the second optical element is pi or zero, or the target phase difference is a positive value.
The motor rotation speed control method according to any one of claims 1 to 5, characterized by further comprising: acquiring a phase compensation value;

the correcting the speed and/or position of the first motor and/or the second motor comprises:

correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor.
The motor speed control method according to any one of claims 1 to 6, wherein the acquiring the phase relationship between the first motor and the second motor during rotation of the motor includes:

respectively acquiring actual phases of the first motor and the second motor through respective photoelectric encoders;

respectively obtaining theoretical phases of the first motor and the second motor through calculation;

respectively carrying out fusion calculation on the actual phase and the theoretical phase of the first motor and the second motor to obtain the phase of the first motor and the phase of the second motor;

and determining the phase relation between the first motor and the second motor according to the phase of the first motor and the phase of the second motor.
The motor speed control method according to any one of claims 1 to 6, wherein the acquiring the phase relationship between the first motor and the second motor during rotation of the motor includes:

acquiring an actual phase of a first motor through a rotation angle of a zero position of a photoelectric encoder of the first motor;

acquiring the actual phase of a second motor through the rotation angle of the zero position of a photoelectric encoder of the second motor;

and determining the phase relation between the first motor and the second motor according to the actual phase of the first motor and the actual phase of the second motor.
The motor speed control method according to claim 8, wherein the phase compensation value is used to correct a phase difference between a null position of the load element of the first motor and a corresponding null position of the photoelectric encoder; and/or for correcting the phase difference between the zero position of the load element of the second motor and the zero position of the corresponding photoelectric encoder.
The motor speed control method according to claim 7, wherein the obtaining of the theoretical phases of the first motor and the second motor, respectively, by calculation includes:

respectively acquiring voltage and current information of the first motor and the second motor;

performing a calculation based on the voltage and current information to obtain theoretical phases for the first and second motors.
The motor speed control method according to claim 1, wherein the correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor includes:

outputting a rotation speed reference value and/or a position reference value according to the phase relation;

outputting the rotating speed reference value and/or the position reference value to a control module;

the control module controls the rotating speed of the first motor and/or the second motor to ensure that the first motor and/or the second motor rotate according to the rotating speed set value and the target phase relation.
The motor speed control method according to claim 11, characterized by further comprising:

after the position reference value is output to the control module, the position reference value is processed by a position control ring and a speed control ring in sequence, and then the rotating speed of the first motor and/or the second motor is controlled by a magnetic field orientation algorithm.
The motor speed control method according to claim 1, wherein the correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor includes:

after the set rotating speed values are input to the first motor and the second motor, integral conversion is carried out on the rotating speeds to obtain the position information of the first motor and the second motor.
The motor speed control method according to any one of claims 1 to 13, wherein the first motor and the second motor are arranged side by side along an optical path;

and the first motor and the second motor are respectively provided with a hollow part and are respectively used for accommodating one wedge-shaped prism and driving the wedge-shaped prism to rotate at the same speed and in opposite rotation directions.
The method as claimed in claim 14, wherein the motor module further comprises a third motor for driving a third optical element to rotate at a different speed from the first and second motors.
The motor speed control method according to any one of claims 1 to 15, wherein the first motor and the second motor are time-divisionally alternately controlled by the same controller.
The motor speed control method according to claim 16, wherein the first motor and the second motor are alternately controlled by the same controller in different control periods, respectively, wherein in two adjacent control periods:

in a first control period, the first motor is controlled by the controller, and the second motor maintains the control state in the last control period;

in a second control period, the second motor is controlled by the controller, and the first motor maintains a control state in the first control period.
The motor speed control method according to claim 17, characterized by comprising:

determining a duty cycle of a PMW signal for controlling the first motor as a function of speed and/or position of the first motor during the first control period; controlling the first motor with a PWM signal having the duty cycle;

during the second control period, the duty cycle of the PMW signal of the first motor remains the same as the PMW signal of the first motor during the first control period.
The motor speed control method according to any one of claims 16 to 18, wherein the phase acquisition of the first motor and the second motor is performed by the same chip.
A control method of a scanning module is characterized in that the scanning module comprises a motor module and an optical element module;

the motor module comprises a first motor and a second motor, the optical element module comprises a first optical element and a second optical element, the first motor is used for driving the first optical element to rotate, and the second motor is used for driving the second optical element to rotate;

the scanning module control method comprises the following steps:

the motor module controller according to any one of claims 1 to 19 controls the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate, so as to ensure that the first optical element and the second optical element rotate at the set rotation speed value and the target phase relationship.
The scan module control method of claim 20, wherein the first optical element and the second optical element are both wedge prisms.
The method as claimed in claim 20 or 21, wherein the motor module further comprises a third motor, and the optical element module further comprises a third optical element, wherein the third motor is configured to rotate the third optical element at a different speed from the first motor and the second motor.
The scan module control method of claim 22, wherein the third optical element is a wedge prism, a mirror, or a galvanometer.
A method for controlling a ranging apparatus, the method comprising:

emitting a light pulse along an outgoing light path;

the method of claim 20 controls the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate, so as to ensure that the first optical element and the second optical element rotate at the set rotation speed value and the target phase relationship, and the rotating first optical element and the rotating second optical element are respectively located on the light pulse emitting path and used for changing the transmission direction of the light pulse;

receiving at least a portion of the transmitted light pulses reflected back through the object;

and acquiring the distance between the distance measuring device and the object according to the received light pulse.
The method of controlling a distance measuring device according to claim 24, wherein the first optical element and the second optical element are both wedge prisms.
The ranging apparatus control method according to claim 24 or 25, further comprising:

and the third optical element is positioned on an emergent light path of the optical pulse and used for changing the transmission direction of the optical pulse.
The method of controlling a distance measuring device according to claim 26, wherein the third optical element is a wedge prism, a mirror, or a galvanometer.
The utility model provides a motor module, its characterized in that includes motor module and control module, motor module includes first motor and second motor, control module is used for:

inputting a set rotating speed value to the first motor and the second motor;

acquiring a phase relation between the first motor and the second motor in a motor rotation process;

and correcting the speed and/or position of the first motor and/or the second motor through the phase relationship of the first motor and the second motor so as to ensure that the first motor and the second motor rotate at the rotating speed set value and the target phase relationship.
The motor module of claim 28, wherein the phase relationship of the first motor and the second motor comprises a phase difference of the first motor and the second motor, and the target phase relationship comprises a target phase difference of the first motor and the second motor; alternatively, the first and second electrodes may be,

the phase relationship of the first motor and the second motor includes a phase sum of the first motor and the second motor, and the target phase relationship includes a target phase sum of the first motor and the second motor.
The electric machine module according to claim 29, characterized in that the phase difference between the first electric machine and the second electric machine is in particular the phase difference between the zero position of the first electric machine and the zero position of the second electric machine;

the target phase difference between the first motor and the second motor is specifically a target phase difference between a zero position of the first motor and a zero position of the second motor.
The motor module of claim 29 or 30, wherein the first motor and the second motor are disposed side-by-side along the optical path, the first motor is configured to rotate the first optical element, the second motor is configured to rotate the second optical element, and the first optical element and the second optical element have the same zero position;

the target phase relationship includes: the target phase sum between the null of the first optical element and the null of the second optical element is a fixed value, or the target phase difference is a fixed value.
The electric machine module of claim 31, wherein the target phase relationship comprises: the target phase sum between the zero position of the first optical element and the zero position of the second optical element is pi or zero, or the target phase difference is a positive value.
The electric machine module of any one of claims 28 to 32, wherein the control method further comprises: acquiring a phase compensation value;

the correcting the speed and/or position of the first motor and/or the second motor comprises:

correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor.
The motor module of any one of claims 28 to 33, wherein the obtaining the phase relationship between the first motor and the second motor during rotation of the motor comprises:

respectively acquiring actual phases of the first motor and the second motor through respective photoelectric encoders;

respectively obtaining theoretical phases of the first motor and the second motor through calculation;

respectively carrying out fusion calculation on the actual phase and the theoretical phase of the first motor and the second motor to obtain the phase of the first motor and the phase of the second motor;

and determining the phase relation between the first motor and the second motor according to the phase of the first motor and the phase of the second motor.
The motor module of any one of claims 28 to 33, wherein the obtaining the phase relationship between the first motor and the second motor during rotation of the motor comprises:

acquiring an actual phase of a first motor through a rotation angle of a zero position of a photoelectric encoder of the first motor;

acquiring the actual phase of a second motor through the rotation angle of the zero position of a photoelectric encoder of the second motor;

and determining the phase relation between the first motor and the second motor according to the actual phase of the first motor and the actual phase of the second motor.
The electric motor module of claim 35, wherein the phase compensation value is configured to correct a phase difference between a null position of the load element of the first electric motor and a corresponding null position of the photoelectric encoder; and/or for correcting the phase difference between the zero position of the load element of the second motor and the zero position of the corresponding photoelectric encoder.
The electric machine module of claim 34, wherein the calculating theoretical phases for the first and second electric machines comprises:

respectively acquiring voltage and current information of the first motor and the second motor;

performing a calculation based on the voltage and current information to obtain theoretical phases for the first and second motors.
The motor module of claim 28, wherein the correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor comprises:

outputting a rotation speed reference value and/or a position reference value according to the phase relation;

outputting the rotating speed reference value and/or the position reference value to a control module;

the control module controls the rotating speed of the first motor and/or the second motor to ensure that the first motor and/or the second motor rotate according to the rotating speed set value and the target phase relation.
The electric machine module of claim 38, wherein the method further comprises:

after the position reference value is output to the control module, the position reference value is processed by a position control ring and a speed control ring in sequence, and then the rotating speed of the first motor and/or the second motor is controlled by a magnetic field orientation algorithm.
The motor module of claim 28, wherein the correcting the speed and/or position of the first motor and/or the second motor by the phase compensation value and the phase relationship of the first motor and the second motor comprises:

after the set rotating speed values are input to the first motor and the second motor, integral conversion is carried out on the rotating speeds to obtain the position information of the first motor and the second motor.
The motor module of any of claims 1-40, wherein the first motor and the second motor are positioned side-by-side along a light path;

and the first motor and the second motor are respectively provided with a hollow part and are respectively used for accommodating one wedge-shaped prism and driving the wedge-shaped prism to rotate at the same speed and in opposite rotation directions.
The electrical machine module of claim 41, further comprising a third electrical machine configured to rotate a third optical element at a different rotational speed than the first and second electrical machines.
The electric machine module of any one of claims 1 to 42, wherein the first electric machine and the second electric machine are time-division alternately controlled by the same controller.
The motor module of claim 43, wherein the first motor and the second motor are alternately controlled by the same controller in different control cycles, wherein in two adjacent control cycles:

in a first control period, the first motor is controlled by the controller, and the second motor maintains the control state in the last control period;

in a second control period, the second motor is controlled by the controller, and the first motor maintains a control state in the first control period.
The electric machine module of claim 44, wherein the method comprises:

determining a duty cycle of a PMW signal for controlling the first motor as a function of speed and/or position of the first motor during the first control period; controlling the first motor with a PWM signal having the duty cycle;

during the second control period, the duty cycle of the PMW signal of the first motor remains the same as the PMW signal of the first motor during the first control period.
The motor module of any of claims 43 to 45, wherein the phase acquisition of the first motor and the second motor is performed by the same chip.
A scanning module is characterized by comprising a motor module, an optical element module and a control module;

the motor module comprises a first motor and a second motor, the optical element module comprises a first optical element and a second optical element, the first motor is used for driving the first optical element to rotate, and the second motor is used for driving the second optical element to rotate;

the control module is used for:

the motor module controller according to any one of claims 1 to 19 controls the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate, so as to ensure that the first optical element and the second optical element rotate at the set rotation speed value and the target phase relationship.
The scan module of claim 47, wherein the first optical element and the second optical element are both wedge prisms.
The scan module of claim 47 or 48, wherein the motor module further comprises a third motor, and the optical element module further comprises a third optical element, wherein the third motor is configured to rotate the third optical element at a different speed than the first motor and the second motor.
The scan module control method of claim 49, wherein the third optical element is a wedge prism, a mirror, or a galvanometer.
A ranging apparatus, comprising:

a light source for emitting light pulses along an exit light path;

a control module, configured to control the first motor and the second motor to respectively drive the first optical element and the second optical element to rotate by using the scan module control method of claim 47, so as to ensure that the first optical element and the second optical element rotate at the set rotation speed and the target phase relationship, where the first optical element and the second optical element that rotate are respectively located on the light pulse emitting path and configured to change a transmission direction of the light pulse;

a detector for receiving at least part of the emitted light pulses reflected back through the object and for deriving a distance of the ranging device from the received light pulses.
A ranging device as claimed in claim 51 wherein the first and second optical elements are wedge prisms.
A ranging apparatus as claimed in claim 51 or 52 wherein the method further comprises:

and the third optical element is positioned on an emergent light path of the optical pulse and used for changing the transmission direction of the optical pulse.
A ranging device as claimed in claim 53 wherein the third optical element is a wedge prism, mirror or galvanometer.