Motor-driven moving device and optical system

Abstract

The invention provides a motor-driven mobile device and an optical system, and the device is characterized in that the device comprises a mobile connecting piece which is connected with a target object; the motor is connected with the movable connecting piece and drives the movable connecting piece to move; and the control module is used for controlling the motor to move the target object to the target position. And the control module performs FOC control on the operation of the motor through the current loop, the speed loop and the position loop, so that the motor can drive the movable connecting piece to perform micron-level precision displacement. In a word, the method can realize accurate displacement to obtain a clear interference image.

Description

Technical Field

[0001] The invention belongs to the field of motor control, and in particular relates to a motor-driven mobile device and an optical system. Background Art

[0002] In optical interferometry, collimating lenses play a vital role. Their main function is to convert the light beam from the light source into a parallel beam. In interferometry, in order to obtain a clear and stable interference pattern, it is necessary to ensure that two or more beams of light have the same directionality when they meet, that is, they are parallel. Through its optical design, the collimating lens can effectively adjust the divergent or converging light beams into parallel beams, thus meeting the basic requirements of interferometry. Since interferometry has high requirements for the parallelism of the light beam, the use of collimating lenses can significantly improve the accuracy of the measurement. If the light beams are not completely parallel, additional phase differences or optical path differences may occur when they meet, which will affect the clarity and accuracy of the interference pattern. Through the correction of the collimating lens, this error can be minimized, making the measurement results more reliable.

[0003] When it is necessary to replace different lasers, such as multi-wavelength laser interferometers, the collimation of the outgoing beam will change when the wavelength changes due to the chromatic aberration of the collimation system itself. Therefore, in order to obtain accurate measurement results, it is necessary to ensure that the collimation system can move along the optical axis in the multi-wavelength laser interferometer so that the outgoing beam is always parallel light with good collimation.

[0004] In addition, when measuring optical elements or optical systems at different distances, the position of the CCD needs to be adjusted to make the interference pattern clear. However, the existing method of replacing lasers with different wavelengths is adjusted manually, which will cause artificial errors in the parallelism of the collimating lens. In addition, most of the common optical device control methods on the market use stepper motors, which have poor stability and are prone to jitter, thus affecting the measurement results.

[0005] Therefore, existing optical interferometry instrument settings still have the problem that the position of the instrument needs to be manually adjusted, or the accuracy of automated position adjustment is poor. Summary of the invention

[0006] The present invention is made to solve the above-mentioned problems, and its object is to provide a motor-driven moving device and an optical system.

[0007] The present invention provides a motor-driven moving device for moving a target object to a target position, and has the following characteristics: a moving connection piece connected to the target object; a motor connected to the moving connection piece and driving the moving connection piece to move; a control module for controlling the motor to move the target object to the target position, wherein the control module includes: an encoding unit for collecting the actual rotation speed and actual position of the motor; a position comparison unit for comparing the target position with the actual position to generate a position deviation value; a position loop PI control unit for generating a target rotation speed according to the position deviation value; a rotation speed comparison unit for comparing the target rotation speed with the actual rotation speed to generate a rotation speed deviation value; a rotation speed loop PI control unit for generating a q-axis current target value according to the rotation speed deviation value; a current collection unit for collecting the three-phase current of the motor; a transformation unit for performing Clarke transformation and Park transformation on the three-phase current in sequence to obtain a d-axis current value and a q-axis current value. current value; a d-axis current comparison unit, storing a preset d-axis current target value, for comparing the d-axis current target value with the d-axis current value to obtain a d-axis deviation current value; a d-axis current loop PI control unit, for generating a d-axis voltage value according to the d-axis deviation current value; a q-axis current comparison unit, for comparing the q-axis current target value with the q-axis current value to obtain a q-axis deviation current value; a q-axis current loop PI control unit, for generating a q-axis voltage value according to the q-axis deviation current value; an inverse PARK transformation unit, for performing an inverse Park transformation on the q-axis deviation current value and the q-axis voltage value to generate a first voltage value and a second voltage value in a three-phase coordinate system; a pulse unit, for performing SVPWM processing on the first voltage value and the second voltage value to generate a pulse control signal; a three-phase circuit unit, for converting the input direct current into a corresponding three-phase alternating current according to the pulse control signal, and the three-phase alternating current is used to drive the motor to operate and move the target object to the target position.

[0008] The motor-driven mobile device provided by the present invention may also have the following features: In the SVPWM process, the corresponding sector is selected according to the N value calculated from the first voltage value and the second voltage value, and the calculation expression of the N value is: r1 =u β , N=A+2B+4C, where N is the N value, u α is the first voltage value, u β is the second voltage value.

[0009] The motor-driven mobile device provided by the present invention may also have the following features: in the SVPWM process, the intermediate variables X, Y and Z are calculated according to the first voltage value and the second voltage value, and the calculation expressions of the intermediate variables X, Y and Z are: Where uα is the first voltage value, u β is the second voltage value, U dc is the voltage corresponding to the direct current, T is the time for the two basic vectors to synthesize the output voltage vector, and the space voltage vector action time of each sector is obtained according to the intermediate variables X, Y and Z, specifically: for the first sector, the space voltage vector action time corresponding to the first sector value is -Z, and the space voltage vector action time corresponding to the second sector value is X; for the second sector, the space voltage vector action time corresponding to the first sector value is Z, and the space voltage vector action time corresponding to the second sector value is Y; for the third sector, the space voltage vector action time corresponding to the first sector value is X, and the space voltage vector action time corresponding to the second sector value is -Y; for the fourth sector, the space voltage vector action time corresponding to the first sector value is -X, and the space voltage vector action time corresponding to the second sector value is Z; for the fifth sector, the space voltage vector action time corresponding to the first sector value is -Y, and the space voltage vector action time corresponding to the second sector value is -Z; for the sixth sector, the space voltage vector action time corresponding to the first sector value is Y, and the space voltage vector action time corresponding to the second sector value is -X.

[0010] The motor-driven mobile device provided by the present invention may also have the following features: In the SVPWM processing, the seven-segment SVPWM is used to calculate the switch state switching time T according to the time T of synthesizing the output voltage vector of the two basic vectors and the action times T1 and T2 of the basic vectors. a , T b and T c , switch state switching time T a , T b and T c The calculation expression is: Three switching moments of each sector and switch state switching time T a , T b and T c The corresponding relationship is: for the first sector, the three switching moments correspond to the switch state switching time T a , T b and T c ; For the second sector, the three switching moments correspond to the switch state switching time T b , T a and T c ; For the third sector, the three switching moments correspond to the switch state switching time T c , T a and T b ; For the fourth sector, the three switching moments correspond to the switch state switching time T c , T b and Ta ; For the fifth sector, the three switching moments correspond to the switch state switching time T b , T c and T a ; For the sixth sector, the three switching moments correspond to the switch state switching time T a , T c and T b .

[0011] The present invention also provides an optical system for interference measurement, having the following characteristics, including: a laser source for generating laser light of a specified wavelength; a spectrometer; a collimating lens; a first moving device connected to the collimating lens and used to move the collimating lens to a specified position so that the collimating lens generates parallel outgoing light; a CCD camera; a second moving device connected to the CCD camera and used to move the CCD camera to a specified position so that the CCD camera generates a clear interference image; a measured mirror; and a reference mirror, wherein the first moving device and the second moving device are both motor-driven moving devices according to any of the above claims, and the measured mirror, the reference mirror, the collimating lens, the spectrometer and the CCD camera are arranged in sequence along the optical path.

[0012] The optical system provided by the present invention may also have the following features, further comprising: an upper control device for controlling the first moving device and the second moving device.

[0013] The optical system provided by the present invention may also have the following features: wherein the control module of the first mobile device and the control module of the second mobile device are connected via a CAN bus, a control module is selected from the control module of the first mobile device and the control module of the second mobile device as a main control module, and the upper control device is connected to the main control module via USART to control the first mobile device and the second mobile device.

[0014] Functions and Effects of the Invention

[0015] According to the motor-driven mobile device and optical system involved in the present invention, on the one hand, the mobile device realizes FOC vector control through the control module, improves the disadvantage of easy motor shaking, and improves the movement accuracy to micron level; on the other hand, the mobile device moves the CCD camera and the collimating lens, so that parallel output light can be generated for any laser, and a clear interference image can be obtained. Therefore, the motor-driven mobile device and optical system of the present invention can achieve precise displacement to obtain a clear interference image. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of an optical system in an embodiment of the present invention;

[0017] Figure 2is a block diagram of a motor-driven moving device in an embodiment of the present invention;

[0018] Figure 3 is a block diagram of a control module in an embodiment of the present invention;

[0019] Figure 4 is a schematic diagram of a simulation result of a sector judgment model in an embodiment of the present invention;

[0020] Figure 5 is a schematic diagram of simulation results of waveforms of intermediate variables X, Y and Z within a period in an embodiment of the present invention;

[0021] Figure 6 It is a schematic diagram of the simulation result of the sector switching time calculation in the embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments are combined with the accompanying drawings to specifically illustrate the motor-driven mobile device and optical system of the present invention.

[0023] In this embodiment, an optical system is provided for interference measurement.

[0024] Figure 1 is a schematic diagram of an optical system in an embodiment of the present invention.

[0025] like Figure 1 As shown, the optical system 100 includes a laser source 11, a beam splitter 12, a collimating lens 13, a first moving device 14, a CCD camera 15, a second moving device 16, a measured mirror 17, a reference mirror 18 and an upper control device (not shown in the figure). The measured mirror 17, the reference mirror 18, the collimating lens 13, the beam splitter 12 and the CCD camera 15 are arranged in sequence along the optical path.

[0026] The laser source 11 is used to generate laser light of a specified wavelength. In this embodiment, the laser source 11 can generate laser light of multiple specified wavelengths.

[0027] The beam splitter 12 is used to split the laser light generated by the laser source 11 into two light beams. One part of the light beam is received by the CCD camera 15, and the other part of the light beam is transmitted through the collimating lens 13 and the reference mirror 18 in sequence. After being reflected by the measured mirror 17, it is transmitted through the reference mirror 18, the collimating lens 13 and the beam splitter 12 in sequence, and then is received by the CCD camera 15.

[0028] The first moving device 14 is connected to the collimating lens 13 and is used to move the collimating lens 13 to a specified position so that the collimating lens 13 generates parallel outgoing light.

[0029] The second moving device 16 is connected to the CCD camera 15 and is used to move the CCD camera 15 to a specified position so that the CCD camera 15 generates a clear interference image.

[0030] In this embodiment, both the first moving device 14 and the second moving device 16 are moving devices driven by motors.

[0031] Figure 2 is a block diagram of a motor-driven moving device according to an embodiment of the present invention.

[0032] like Figure 2 As shown, the motor-driven mobile device 200 includes a mobile connection member 21 , a motor 22 and a control module 23 .

[0033] The mobile connector 21 is connected to the target object. In this embodiment, the target object corresponding to the first mobile device 14 is the collimating lens 13, and the collimating lens 13 is arranged on the mobile connector 21 of the first mobile device 14. In this embodiment, the target object corresponding to the second mobile device 16 is the CCD camera 15, and the CCD camera 15 is arranged on the mobile connector 21 of the second mobile device 16.

[0034] The motor 22 is connected to the movable connecting member 21 to drive the movable connecting member 21 to move.

[0035] The control module 23 is used to control the motor 22 to move the target object to a target position.

[0036] Figure 3 is a block diagram of a control module in an embodiment of the present invention.

[0037] like Figure 3 As shown, the control module 23 includes an encoding unit 2301, a position comparison unit 2302, a position loop PI control unit 2303, a speed comparison unit 2304, a speed loop PI control unit 2305, a current acquisition unit 2306, a transformation unit 2307, a d-axis current comparison unit 2308, a d-axis current loop PI control unit 2309, a q-axis current comparison unit 2310, a q-axis current loop PI control unit 2311, an anti-PARK transformation unit 2312, a pulse unit 2313 and a three-phase circuit unit 2314.

[0038] The encoding unit 2301 is used to collect the actual speed and actual position of the motor. In this embodiment, the encoding unit 2301 includes a position sensor using an MT6816CT-ACD chip, which is used to collect the actual position.

[0039] The position comparison unit 2032 is used to compare the target position with the actual position to generate a position deviation value.

[0040] The position loop PI control unit 2303 is used to generate a target speed according to the position deviation value;

[0041] The speed comparison unit 2304 is used to compare the target speed with the actual speed to generate a speed deviation value.

[0042] The speed loop PI control unit 2305 is used to generate a q-axis current target value according to the speed deviation value.

[0043] The current acquisition unit 2306 is used to acquire the three-phase current of the motor.

[0044] The transformation unit 2307 is used to perform Clarke transformation and Park transformation on the three-phase current in sequence to obtain a d-axis current value and a q-axis current value.

[0045] The d-axis current comparison unit 2308 stores a preset d-axis current target value, and is used to compare the d-axis current target value with the d-axis current value to obtain a d-axis deviation current value.

[0046] In this embodiment, the d-axis current target value is 0, so as to make full use of the current and control the q-axis current to maximize the output torque. In other embodiments, the corresponding d-axis current target value can be set as needed, or the d-axis current target value can be input into the d-axis current comparison unit 2308 as a variable.

[0047] The d-axis current loop PI control unit 2309 is used to generate a d-axis voltage value according to the d-axis deviation current value.

[0048] The q-axis current comparison unit 2310 is used to compare the q-axis current target value and the q-axis current value to obtain a q-axis deviation current value.

[0049] The q-axis current loop PI control unit 2311 is used to generate a q-axis voltage value according to the q-axis deviation current value.

[0050] The inverse PARK transformation unit 2312 is used to perform an inverse Park transformation on the q-axis deviation current value and the q-axis voltage value to generate a first voltage value and a second voltage value in a three-phase coordinate system.

[0051] The pulse unit 2313 is used to perform SVPWM processing on the first voltage value and the second voltage value to generate a pulse control signal.

[0052] The SVPWM processing includes three important parts: sector judgment, adjacent action vector duration calculation and voltage vector switching point calculation. The sectors include the first sector I, the second sector II, the third sector III, the fourth sector IV, the fifth sector V and the sixth sector VI.

[0053] The calculation methods of the above three important parts in this embodiment are described below in conjunction with the accompanying drawings.

[0054] In the SVPWM process, the corresponding sector is selected according to the N value calculated according to the first voltage value and the second voltage value. The calculation expression of the N value is:

[0055] u r1 =u β ,

[0056]

[0057]

[0058] N=A+2B+4C,

[0059] Where N is the N value, u α is the first voltage value, u β is the second voltage value.

[0060] According to the above calculation expression, the results of sectors corresponding to different N values ​​are shown in the following table:

[0061] Sector Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Ⅵ N value 3 1 5 4 6 2

[0062] The first row in the table above contains the sectors, and the second row contains the N values ​​corresponding to the sectors. For example, the cell in the second row and second column indicates that when the N value is 3, the corresponding sector is the first sector.

[0063] In this embodiment, a corresponding sector judgment model is constructed in Matlab according to the above formula. The sector judgment model transforms the three-phase input voltage to obtain the voltage in the two-phase rotating coordinate system, and then calculates the N value.

[0064] Figure 4 It is a schematic diagram of the simulation results of the sector judgment model in the embodiment of the present invention.

[0065] like Figure 4 As shown, the horizontal axis is time T, in seconds, and the vertical axis is the value of N. It can be seen that within the cycle, the value of N changes to 3, 1, 5, 4, 6, and 2, which correspond to the sectors in the above table respectively.

[0066] The horizontal axis is the direction of the first voltage value vector, and the vertical axis is the direction of the second voltage value vector. Six sectors are obtained by dividing the six basic vectors U1, U2, U3, U4, U5 and U6 in sequence. The output voltage vector of each sector can be represented by the corresponding basic vector. In this process, T is the time for the two basic vectors to synthesize the output voltage vector, and T1 and T2 are the action times of the two basic vectors. For example, the output vector U of the first sector out It can be represented by U1 and U2, and its expression is:

[0067]

[0068] Where U0 is the zero vector.

[0069] In the following calculation of adjacent action vector duration and voltage vector switching point, the calculation and expression of the space voltage vector action time and switch state switching time are performed in the first sector.

[0070] In the SVPWM process, the intermediate variables X, Y and Z are calculated according to the first voltage value and the second voltage value. The calculation expressions of the intermediate variables X, Y and Z are:

[0071]

[0072] Where u α is the first voltage value, u β is the second voltage value, U dc is the voltage corresponding to the direct current, and T is the time it takes for two basic vectors to synthesize an output voltage vector.

[0073] The spatial voltage vector action time of each sector is obtained according to the intermediate variables X, Y and Z, specifically:

[0074] For the first sector, the space voltage vector action time corresponding to the first sector value is -Z, and the space voltage vector action time corresponding to the second sector value is X; for the second sector, the space voltage vector action time corresponding to the first sector value is Z, and the space voltage vector action time corresponding to the second sector value is Y; for the third sector, the space voltage vector action time corresponding to the first sector value is X, and the space voltage vector action time corresponding to the second sector value is -Y; for the fourth sector, the space voltage vector action time corresponding to the first sector value is -X, and the space voltage vector action time corresponding to the second sector value is Z; for the fifth sector, the space voltage vector action time corresponding to the first sector value is -Y, and the space voltage vector action time corresponding to the second sector value is -Z; for the sixth sector, the space voltage vector action time corresponding to the first sector value is Y, and the space voltage vector action time corresponding to the second sector value is -X.

[0075] The space voltage vector action time of each sector mentioned above can be expressed as the following table:

[0076] Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Ⅵ TX -Z Z X -X -Y Y TY X Y -Y Z -Z -X

[0077] The first line in the table above is each sector, and the second line is the first sector value T of each sector. X The corresponding space voltage vector action time, the third line is the second sector value T of each sector Y The corresponding space voltage vector action time.

[0078] In this embodiment, a corresponding model is constructed in Matlab according to the above-mentioned spatial voltage vector action time.

[0079] Figure 5 It is a schematic diagram of simulation results of waveforms of intermediate variables X, Y and Z within a period in an embodiment of the present invention.

[0080] like Figure 5 As shown, the horizontal axis is time T, in seconds, and the vertical axis is the vector calculation duration. It can be seen that within the period, the intermediate variables X, Y and Z are sinusoidal waves in sequence.

[0081] In SVPWM processing, the seven-segment SVPWM is used to calculate the switch state switching time T according to the time T of the output voltage vector synthesized by two basic vectors and the action time T1 and T2 of the basic vectors. a , T b and T c , switch state switching time T a , T b and T c The calculation expression is:

[0082]

[0083] Three switching moments of each sector and switch state switching time T a , T b and T c The corresponding relationship is:

[0084] For the first sector, the three switching moments correspond to the switch state switching time T a , T b and T c ; For the second sector, the three switching moments correspond to the switch state switching time T b , T a and T c ; For the third sector, the three switching moments correspond to the switch state switching time T c , T a and T b ; For the fourth sector, the three switching moments correspond to the switch state switching time T c , T b and T a ; For the fifth sector, the three switching moments correspond to the switch state switching time T b , T c and T a ; For the sixth sector, the three switching moments correspond to the switch state switching time T a , T c and T b .

[0085] The three switching moments of each sector and the switch state switching time can be expressed as the following table:

[0086] I II III IV V VI <![CDATA[F switch1 ]]> <![CDATA[T a ]]> <![CDATA[T b ]]> <![CDATA[T c ]]> <![CDATA[T c ]]> <![CDATA[T b ]]> <![CDATA[T a ]]> <![CDATA[T switch2 ]]> <![CDATA[T b ]]> <![CDATA[T a ]]> <![CDATA[T a ]]> <![CDATA[T b ]]> <![CDATA[T c ]]> <![CDATA[T c <!-- 6 -->]]> <![CDATA[F switch2 ]]> <![CDATA[T c ]]> <![CDATA[T c ]]> <![CDATA[T b ]]> <![CDATA[T a ]]> <![CDATA[T a ]]> <![CDATA[T b ]]>

[0087] The first row in the table above shows the sectors, and the second to fourth rows show the three switching times T. switch1 , T switch2 and T switch2 The corresponding switch state switching time.

[0088] In this embodiment, a seven-segment time allocation simulation model is established in Matlab to generate a sector switching time calculation result.

[0089] Figure 6 It is a schematic diagram of the simulation result of the sector switching time calculation in the embodiment of the present invention.

[0090] like Figure 6 As shown, the horizontal axis is time T, in seconds s, and the vertical axis is voltage, in V. It can be seen that the three switching moments T switch1 , T switch2 and T switch2 The voltage waveform is saddle-shaped during the cycle.

[0091] In this embodiment, the position comparison unit 2302, the position loop PI control unit 2303, the speed comparison unit 2304, the speed loop PI control unit 2305, the current acquisition unit 2306, the transformation unit 2307, the d-axis current comparison unit 2308, the d-axis current loop PI control unit 2309, the q-axis current comparison unit 2310, the q-axis current loop PI control unit 2311, the anti-PARK transformation unit 2312 and the pulse unit 2313 are integrated and set in the STM32F103C8T6 chip.

[0092] The three-phase circuit unit 2314 is used to convert the input direct current into corresponding three-phase alternating current according to the pulse control signal. The three-phase alternating current is used to drive the motor 22 to operate and move the target object to the target position.

[0093] In this embodiment, the three-phase circuit unit 2314 includes a FD6288T driver chip and a driver circuit. The driver circuit is composed of 6 SVG086R0NT MOSFETs. The FD6288T driver chip controls the switching of the 6 SVG086R0NT MOSFETs according to the pulse control signal. Each phase of the motor 22 is connected to 2 MOSFETs to form a dual-channel drive, which improves the stability of the driver circuit.

[0094] In this embodiment, the CCD camera 15 and the collimating lens 13 are finely moved and controlled only by the motor-driven moving device 200 to achieve micron-level movement. In other embodiments, fine movement control can also be performed on other devices as needed, such as the laser source 11, that is, the laser source 11 is connected to the motor-driven moving device 200 to enable the laser source 11 to achieve fine movement.

[0095] The upper control device is used to control the first moving device 14 and the second moving device 16 .

[0096] The control module 23 of the first mobile device 14 is connected to the control module 23 of the second mobile device 16 by means of a CAN bus. In this embodiment, the CAN bus can assign different IDs to various devices to form a system.

[0097] A control module 23 is selected from the control module 23 of the first mobile device 14 and the control module 23 of the second mobile device 16 as a main control module, and the upper control device 14 is connected to the main control module through USART to control the first mobile device 14 and the second mobile device 16.

[0098] In addition, real-time detection of phase current is a key step in FOC control. In hardware, the collected three-phase current is added with bias voltage through the amplifier circuit, and finally positive and negative currents can be obtained. The dual-resistance current sampling method is a method for detecting motor phase currents. It is often used in closed-loop control of current loops in motor control systems to achieve precise torque control and speed control. The basic principle of this method is to insert resistors in the current paths of the U and V phases of the motor and use Ohm's law to calculate the current value, as follows:

[0099] First, two resistors need to be connected in series to the two phase lines of the motor. Then, the voltage across the resistor is converted into a digital signal through an analog-to-digital converter (ADC), so that the value of each phase current can be obtained. During the operation of the motor, the phase with a shorter sampling window can be discarded at any time, and the current of the third phase can be deduced from Kirchhoff's current law.

[0100] The algorithm of this method is simple, and it only needs to collect data once to reconstruct the three-phase current, so it is fast. In addition, the dual-resistance current sampling method also effectively avoids the defect of a phase sampling window being too narrow. When the three-phase lower bridge arm is fully open, the current of the other two phases is collected instead of the one phase with a too narrow window, and the current of the third phase is obtained by Kirchhoff's current law.

[0101] After the system is powered on, the upper control device initializes and configures the clock and various modules used, such as ADC, PWM, sensor interface, communication interface, etc. After the module is initialized, some system parameters and variables are initialized, such as the initial state of the motor, current loop PI parameters, speed loop PI, position loop PI parameters, etc. Then the initial offset of the motor is corrected. Then the state machine polling or system error check is performed. If there is an error, the error is reported and the motor is stopped. If there is no error, the first mobile device 14 and the second mobile device 16 are controlled according to the start-stop command.

[0102] Functions and Effects of the Embodiments

[0103] According to the motor-driven mobile device and optical system involved in this embodiment, on the one hand, the mobile device is controlled by the control module to realize FOC vector control, improve the disadvantage of easy motor shaking, and improve the movement accuracy to micron level; on the other hand, the mobile device moves the CCD camera and the collimating lens, so that parallel output light can be generated for any laser, and a clear interference image can be obtained. In short, the device and system can achieve precise displacement to obtain a clear interference image.

[0104] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A motor-driven moving device for moving a target object to a target position, characterized in that: include: A mobile connecting member is connected to the target object; A motor, connected to the movable connecting member, driving the movable connecting member to move; a control module, configured to control the motor to move the target object to the target position, Wherein, the control module comprises: An encoding unit, used for collecting the actual speed and actual position of the motor; A position comparison unit, used for generating a position deviation value by comparing the target position with the actual position; A position loop PI control unit, used for generating a target speed according to the position deviation value; A speed comparison unit, configured to generate a speed deviation value by comparing the target speed with the actual speed; A speed loop PI control unit, used for generating a q-axis current target value according to the speed deviation value; A current collection unit, used for collecting the three-phase current of the motor; A transformation unit, used for performing Clarke transformation and Park transformation on the three-phase current in sequence to obtain a d-axis current value and a q-axis current value; a d-axis current comparison unit storing a preset d-axis current target value and used to compare the d-axis current target value with the d-axis current value to obtain a d-axis deviation current value; A d-axis current loop PI control unit, used to generate a d-axis voltage value according to the d-axis deviation current value; a q-axis current comparison unit, used for comparing the q-axis current target value with the q-axis current value to obtain a q-axis deviation current value; A q-axis current loop PI control unit, used for generating a q-axis voltage value according to the q-axis deviation current value; an inverse PARK transformation unit, configured to perform an inverse Park transformation on the q-axis deviation current value and the q-axis voltage value to generate a first voltage value and a second voltage value in a three-phase coordinate system; a pulse unit, configured to perform SVPWM processing on the first voltage value and the second voltage value to generate a pulse control signal; The three-phase circuit unit is used to convert the input direct current into corresponding three-phase alternating current according to the pulse control signal, The three-phase alternating current is used to drive the motor to operate, so that the target object moves to the target position.

2. The motor-driven mobile device according to claim 1, characterized in that: in, In the SVPWM process, a corresponding sector is selected according to the N value calculated according to the first voltage value and the second voltage value. The calculation expression of the N value is: in r1 =in β , N=A+2B+4C, Where N is the N value, u α is the first voltage value, u β is the second voltage value.

3. The motor-driven mobile device according to claim 1, Features: Wherein, in the SVPWM process, intermediate variables X, Y and Z are calculated according to the first voltage value and the second voltage value, The calculation expressions of the intermediate variables X, Y and Z are: Where u α is the first voltage value, u β is the second voltage value, U dc is the voltage corresponding to the DC power, T is the time it takes for two basic vectors to synthesize the output voltage vector, The spatial voltage vector action time of each sector is obtained according to the intermediate variables X, Y and Z, specifically: For the first sector, the space voltage vector action time corresponding to the first sector value is -Z, and the space voltage vector action time corresponding to the second sector value is X; For the second sector, the space voltage vector action time corresponding to the first sector value is Z, and the space voltage vector action time corresponding to the second sector value is Y; For the third sector, the space voltage vector action time corresponding to the first sector value is X, and the space voltage vector action time corresponding to the second sector value is -Y; For the fourth sector, the space voltage vector action time corresponding to the first sector value is -X, and the space voltage vector action time corresponding to the second sector value is Z; For the fifth sector, the space voltage vector action time corresponding to the first sector value is -Y, and the space voltage vector action time corresponding to the second sector value is -Z; For the sixth sector, the space voltage vector action time corresponding to the first sector value is Y, and the space voltage vector action time corresponding to the second sector value is -X.

4. The motor-driven mobile device according to claim 1, Features: Among them, in the SVPWM processing, the seven-segment SVPWM is used to calculate the switch state switching time T according to the time T of the output voltage vector synthesized by two basic vectors and the action time T1 and T2 of the basic vectors. a , T b and T c , The switch state switching time T a , T b and T c The calculation expression is: The three switching moments of each sector and the switch state switching time T a , T b and T c The corresponding relationship is: For the first sector, the three switching moments correspond to the switch state switching time T a , T b and T c ; For the second sector, the three switching moments correspond to the switch state switching time T b , T a and T c ; For the third sector, the three switching moments correspond to the switch state switching time T c , T a and T b ; For the fourth sector, the three switching moments correspond to the switch state switching time T c , T b and T a ; For the fifth sector, the three switching moments correspond to the switch state switching time T b , T c and T a ; For the sixth sector, the three switching moments correspond to the switch state switching time T a , T c and T b .

5. An optical system for interferometric measurement, characterized in that: include: A laser source, used for generating laser light of a specified wavelength; Spectrum splitter; Collimating lens; A first moving device, connected to the collimating lens, for moving the collimating lens to a specified position so that the collimating lens generates parallel outgoing light; CCD camera; a second moving device, connected to the CCD camera, and used to move the CCD camera to a specified position so that the CCD camera generates a clear interference image; The mirror under test; Reference mirror, Wherein, the first moving device and the second moving device are both motor-driven moving devices as described in any one of claims 1 to 4, The measured mirror, the reference mirror, the collimating lens, the beam splitter and the CCD camera are arranged in sequence along the optical path.

6. The optical system according to claim 5, characterized in that Also includes: The upper control device is used to control the first moving device and the second moving device.

7. The optical system according to claim 6, characterized in that: in, The control module of the first mobile device is connected to the control module of the second mobile device via a CAN bus. Select one control module from the control module of the first mobile device and the control module of the second mobile device as a main control module, The upper control device is connected to the main control module through USART communication to control the first mobile device and the second mobile device.

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