Optical mechanical scanning control device and motor control method

Abstract

The application discloses an optical mechanical scanning control device, which comprises a control circuit unit, a power unit, a spatial position feedback unit, a protection unit and a temperature measurement unit; the control circuit unit generates a three-section scanning motion curve according to two end limit positions and generates a PWM signal with a duty ratio suitable for the three-section scanning motion curve; the three-section scanning motion curve comprises a start-up acceleration process of a first section, a uniform motion process of a second section and a stop deceleration process of a third section, wherein the uniform speed of the second section is a target speed of spectral imaging; the duty ratio value of the PWM signal is obtained after adaptive adjustment through fitting calculation according to current temperature data and a pre-set temperature-PWM value data table, so that the scanning speed is adaptively matched in a full temperature range; the power unit is used for driving scanning of an optical scanning component according to the PWM signal of the control circuit unit.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to an optical-mechanical scanning control device and a motor control method. Background Technology

[0002] Scanning imaging relies on detectors and scanning lenses to sample target objects point-by-point and line-by-line in an instantaneous field of view to obtain information on the electromagnetic radiation characteristics of the target objects and form an image within a specific spectral band. Its detection bands can include ultraviolet, infrared, visible light, and microwave bands, and there are three imaging methods: electronic scanning imaging, optomechanical scanning, and solid-state scanning imaging. Optomechanical scanning primarily involves the field of motor control technology, placing extremely high demands on the motion stability of the scanning motion control device and the real-time performance of the synchronization signal; otherwise, spectral imaging cannot be achieved. Furthermore, traditional optomechanical scanning methods have complex optomechanical structures, numerous debugging parameters, and insufficient intelligence. Summary of the Invention

[0003] The main objective of this invention is to provide an optical-mechanical scanning control device and a motor control method that can achieve adaptive matching of scanning speed across the entire temperature range, greatly simplify the motion parameter setting process, improve motion stability, and provide high-precision synchronization signals based on spatial position in real time.

[0004] The technical solution adopted in this invention is:

[0005] An optical-mechanical scanning control device is provided, including a control circuit unit, a power unit, a spatial position feedback unit, a protection unit, and a temperature measurement unit;

[0006] The temperature measurement unit is used to collect temperature data and send it to the control circuit unit;

[0007] The spatial position feedback unit is used to collect the position data of the optical scanning component in real time and send it to the control circuit unit;

[0008] The protection unit is placed at both extreme positions of the movement range of the spatial position feedback unit, serving as a limit protection function and a zeroing function;

[0009] The control circuit unit generates a three-segment scanning motion curve based on the extreme positions at both ends, and generates a PWM signal adapted to the three-segment scanning motion curve. The three-segment scanning motion curve includes a first segment of acceleration, a second segment of uniform motion, and a third segment of deceleration. The uniform speed in the second segment is the target speed for spectral imaging. The duty cycle of the PWM signal is calculated by fitting the current temperature data and a preset temperature-PWM value data table, and then adaptively adjusted.

[0010] The power unit is used to drive the optical scanning component to move along the three-segment scanning motion curve to complete the scanning according to the PWM signal of the control circuit unit.

[0011] Following the above technical solution, the temperature measurement unit sends temperature data to the control circuit unit via the SPI interface.

[0012] Following the above technical solution, the control circuit unit specifically generates a PWM control signal with a suitable duty cycle through an internal timer.

[0013] Following the above technical solution, the spatial position feedback unit is a linear grating.

[0014] Following the above technical solution, the specific process for fitting and calculating the PWM value corresponding to the initial speed is as follows: Based on the current actual temperature, look up the table to obtain the temperature range within T... n and T (n+1) Fitting and calculating the current PWM value S: S = S n +(S n -S (n+1) )*(TT n ) / (T n -T (n+1) The temperature-PWM value data table is derived from pre-experimental data obtained at different temperatures T. n The corresponding PWM value S at a fixed and suitable speed. n The resulting data table {S n ,T n}, n = 0, 1, 2, 3...

[0015] Following the above technical solution, the power unit is a DC motor.

[0016] Following the above technical solution, the temperature measuring unit is a temperature sensor.

[0017] According to the above technical solution, the spatial position feedback unit is placed on the optical scanning component and, driven by the power unit, moves towards the minimum position value until the corresponding protection unit is triggered and the position data is returned to zero.

[0018] Following the above technical solution, during the uniform motion of the second segment, the control circuit unit calculates and outputs a high-precision synchronization signal based on the position data fed back by the spatial position feedback unit.

[0019] The present invention also provides an optical-mechanical scanning control method, comprising the following steps:

[0020] Collect temperature data;

[0021] The extreme position data corresponding to the optical scanning component is tested in advance, and a three-segment scanning motion curve is planned based on this. It includes the first segment of the start-up acceleration process, the second segment of the uniform motion process, and the third segment of the stop deceleration process. The uniform speed in the second segment is the target speed for spectral imaging.

[0022] A PWM signal adapted to the three-segment scanning motion curve is generated; the duty cycle of the PWM signal is calculated based on the current temperature data and a preset temperature-PWM value data table, and then adaptively adjusted.

[0023] The optical scanning component is driven by a PWM signal to move along a three-segment scanning motion curve to complete the scan. The beneficial effects of this invention are: it enables adaptive matching of scanning speed across the entire temperature range, greatly simplifies the motion parameter setting process, calculates and implements the three-segment scanning motion curve, significantly improves motion stability, and provides a high-precision synchronization signal based on spatial position in real time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the optical-mechanical scanning control device according to an embodiment of the present invention;

[0026] Figure 2 This is a flowchart of the motor control method according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the three-segment scanning motion curve of an embodiment of the present invention;

[0028] Figure 4 This is a flowchart of the adaptive motor speed adjustment process according to an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] like Figure 1As shown, the optical-mechanical scanning control device of this embodiment includes a control circuit unit 11, a power unit 12, a spatial position feedback unit 13, a protection unit 14, and a temperature measurement unit 15. The power unit 12 can be a DC motor.

[0031] The temperature measurement unit 15 feeds back the temperature data to the control circuit unit 11 through the SPI interface. The control circuit unit 11 fits the initial speed according to the temperature data and generates a PWM signal with a suitable duty cycle through the internal timer. Finally, the speed adaptive adjustment is used to realize the adaptive matching of the scanning speed of the power unit 12 in the whole temperature range.

[0032] The control circuit unit 11 receives two position signals with a 45° phase difference from the spatial position feedback unit 13 and analyzes the real-time spatial position. Based on the limit position provided by the protection unit 14, the control circuit unit 11 reserves the first acceleration and third deceleration motion curve segments according to preliminary tests, and calculates and designs the second uniform motion curve segment, thus generating a three-segment scanning motion curve (the first segment's acceleration process, the second segment's uniform motion process, and the third segment's deceleration process). The uniform speed of the second segment is the target speed for spectral imaging; this speed is a fixed value and cannot fluctuate with external factors such as ambient temperature. The duty cycle value of the PWM signal is obtained by fitting and calculating based on the current temperature data and a pre-set temperature-PWM value data table, and then adaptively adjusting it, thereby achieving adaptive matching of the scanning speed across the entire temperature range.

[0033] During the second stage of uniform motion, the control circuit unit 11 receives the position data fed back by the spatial position feedback unit 13 and calculates and outputs a high-precision synchronization signal as the clock signal for image output in spectral imaging.

[0034] Because varying ambient temperatures cause different resistances when the motor drives the linear grating, it is necessary to set an appropriate PWM value based on the temperature to generate a motor driving force that matches the resistance, ensuring the device operates at a constant target speed unaffected by ambient temperature. (Refer to...) Figure 4 As shown, the adaptive speed adjustment method for the motor of the present invention is as follows:

[0035] First, an initial PWM value is calculated based on the current temperature and a pre-set temperature-PWM value data table. This initial PWM value is used to generate a corresponding PWM signal and drive the motor to run a fixed distance L. The running time is recorded as T by an internal timer in the controller, and the actual motor speed can be calculated as V = L / T. It is then determined whether the speed has reached the target speed; if not, the PWM value is increased or decreased accordingly, and the motor is driven again while the speed is calculated, until the actual motor speed meets the requirements. Finally, the PWM value required to reach the target speed at the current temperature is temporarily stored, and this PWM value is used to generate the motor drive signal during subsequent scanning motion.

[0036] The specific process for fitting the initial PWM value corresponding to the initial velocity is as follows: Based on the current actual temperature, look up the table to obtain the temperature range within T... n and T (n+1) Fitting and calculating the current PWM value S: S = S n +(S n -S (n+1) )*(TT n ) / (T n -T (n+1) The temperature-PWM value data table is derived from pre-experimental data obtained at different temperatures T. n The corresponding PWM value S at a fixed and suitable speed. n The resulting data table {S n ,T n}, n = 0, 1, 2, 3...

[0037] The adaptive matching of scanning speed across the entire temperature range of this invention solves the following problem: due to the different resistance of the device at different temperatures, the actual operating speed of the motor varies under the same PWM signal drive at different temperatures.

[0038] In another embodiment of the present invention, a DC motor serves as the power unit 12 of the device, a linear grating serves as the spatial position feedback unit 13 of the device, a photoelectric switch serves as the limit position protection unit 14 of the device and provides the zero-point signal of the linear grating, and a DS18B20 temperature sensor serves as the temperature measurement unit 15. The DC motor can drive the linear grating to perform scanning motion, and the photoelectric switch is placed at both ends of the linear grating at their limit positions, serving as a limit protection function and a zero-point function.

[0039] Reference Figure 2 As shown, the motor motion control method of this invention includes the following steps:

[0040] First, the control circuit unit 11 initializes various parameters and signals. The motor drives the linear grating towards its minimum position until the corresponding photoelectric switch is triggered and the position data is reset to zero (the linear grating used is an incremental grating, which only outputs the relative value of the position data, so it needs to be reset first). The temperature measurement unit 15 feeds back the temperature data to the control circuit unit 11 through the SPI interface, then fits the PWM value corresponding to the initial speed based on the temperature data, and generates a PWM signal with a suitable duty cycle through an internal timer. Finally, adaptive adjustment is used to automatically adjust the motor speed until the target speed is reached. The motor drives the linear grating to the starting point of the scanning curve, at which point the motor state initialization is completed.

[0041] This motion device can receive external commands and switch between scanning and stepping modes. In stepping mode, it can control the motor to move in steps, such as controlling the motor to move the linear grating to its extreme values ​​and reading the corresponding position information for subsequent motion curve design and planning. In scanning mode, after scanning is started, the motor can drive the linear grating to move according to a three-segment scanning motion curve.

[0042] After an external stepping mode command is sent, a single-step control command is then sent to drive the motor to rotate and move the linear grating until it reaches the limit position of the photoelectric switch. After an external scanning mode command is sent, the system enters scanning mode.

[0043] After sending the start scan command, the motor drives the linear grating to move along the calculated three-segment scanning motion curve. During the movement, a high-precision synchronization signal based on the spatial position is output synchronously. After completing one scan, it returns to the scanning starting point.

[0044] Reference Figure 3 As shown, the three-segment scanning motion curve of the optical-mechanical scanning control device has six nodes. t1 and t2 are the start and end points of the first segment's acceleration process; t2 and t5 are the start and end points of the second segment's uniform motion process; and t5 and t6 are the start and end points of the third segment's deceleration process. Based on preliminary experiments, acceleration and deceleration motion curve segments for the first and third segments are reserved, and the second segment's uniform motion curve segment is calculated and designed. The middle part of the second segment's uniform motion process, t3-t4, is taken as the effective interval of the scanning motion to ensure the scanning imaging is in the most stable state. A high-precision synchronization signal is output only in the t3-t4 interval as the spectral image output clock.

[0045] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An optical-mechanical scanning control device, characterized in that, It includes a control circuit unit (11), a power unit (12), a spatial position feedback unit (13), a protection unit (14), and a temperature measurement unit (15). Temperature measurement unit (15) is used to collect temperature data and send it to control circuit unit (11); The spatial position feedback unit (13) is used to collect position data of the optical scanning component in real time and send it to the control circuit unit (11). The protection unit (14) is placed at the extreme positions at both ends of the range of motion of the spatial position feedback unit (13), and plays the role of limiting protection and zeroing. The control circuit unit receives two position signals with a 45° phase difference from the spatial position feedback unit and analyzes the real-time spatial position. Based on the extreme positions at both ends, it generates a three-segment scanning motion curve and produces a PWM signal adapted to the three-segment scanning motion curve. The three-segment scanning motion curve includes a first segment of acceleration, a second segment of uniform motion, and a third segment of deceleration. The uniform speed in the second segment is the target speed for spectral imaging. The duty cycle of the PWM signal is calculated by fitting the current temperature data and a pre-set temperature-PWM value data table and then adaptively adjusted. The power unit (12) is used to drive the optical scanning component to move along the three-segment scanning motion curve to complete the scanning according to the PWM signal of the control circuit unit (11).

2. The optical-mechanical scanning control device according to claim 1, characterized in that, The temperature measurement unit (15) sends temperature data to the control circuit unit (11) via the SPI interface.

3. The optical-mechanical scanning control device according to claim 1, characterized in that, The control circuit unit (11) specifically generates a PWM control signal with a suitable duty cycle through an internal timer.

4. The optical-mechanical scanning control device according to claim 1, characterized in that, The spatial position feedback unit (13) is a linear grating.

5. The optical-mechanical scanning control device according to claim 1, characterized in that, The specific process for fitting the PWM value corresponding to the initial velocity is as follows: Based on the current actual temperature, look up the table to determine the temperature range within T. n and T (n+1) Fitting and calculating the current PWM value S: S = S n +(S n -S (n+1) ) (TT n ) / (T n -T (n+1) The temperature-PWM value data table is derived from pre-experimental data obtained at different temperatures T. n The corresponding PWM value S at a fixed and suitable speed. n The resulting data table {S n ,T n }, n=0, 1, 2, 3...

6. The optical-mechanical scanning control device according to claim 1, characterized in that, The power unit (12) is a DC motor.

7. The optical-mechanical scanning control device according to claim 1, characterized in that, The temperature measuring unit (15) is a temperature sensor.

8. The optical-mechanical scanning control device according to claim 1, characterized in that, The spatial position feedback unit (13) is placed on the optical scanning assembly and, driven by the power unit (12), moves toward the minimum position until the corresponding protection unit (14) is triggered and the position data is zeroed.

9. The optical-mechanical scanning control device according to any one of claims 1-8, characterized in that, During the second stage of uniform motion, the control circuit unit (11) calculates and outputs a high-precision synchronization signal based on the position data fed back by the spatial position feedback unit (13).

10. An optical-mechanical scanning control method, characterized in that, Based on the optical-mechanical scanning control device of claim 1, it includes the following steps: Collect temperature data; The extreme position data corresponding to the optical scanning component are tested in advance, and a three-segment scanning motion curve is planned, which includes the first segment of the start-up acceleration process, the second segment of the uniform motion process, and the third segment of the stop deceleration process. The uniform speed in the second segment is the target speed for spectral imaging. A PWM signal adapted to the three-segment scanning motion curve is generated; the duty cycle of the PWM signal is calculated based on the current temperature data and a preset temperature-PWM value data table, and then adaptively adjusted. The optical scanning component is driven by the PWM signal to move along a three-segment scanning motion curve to complete the scan.

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