Sighting target screen displacement control device

Abstract

The utility model provides a sighting target screen displacement control device which comprises a base, a sighting target screen and a driving device, the sighting target screen is arranged on a guide rail of the base in a sliding mode, the sighting target screen is matched with the driving device, a movable grid is fixedly arranged on the sighting target screen, and the movable grid is matched with a fixed grid arranged along the sliding track of the sighting target screen. The driving device is a stepping motor, is fixedly arranged on the base, and is connected with the sighting mark screen through a synchronous belt. And a control mainboard is arranged on the base and is in circuit connection with the driving device, the movable grid and the fixed grid. The beneficial effects of the utility model are that the scheme introduces the displacement sensing module to carry out cooperative control on the displacement of the motor. A closed-loop control mode is formed, and compensation control is carried out on the specific position of the target screen through displacement sensing of the capacitive grating sensor. The device is provided with capacitive grating type sensing for mechanical displacement measurement, so that high precision can be achieved, and the device has the advantages of low cost, small size and the like.

Description

Technical Field

[0001] The utility model relates to the field of displacement control, and more specifically to a sight mark screen displacement control device. Background Art

[0002] At present, many patients with visual impairment can alleviate and improve their condition through proper training by doctors. During the training process, small equipment is often used to present the training target on the focal plane, and the distance between it and the trainee's eyeball needs to be adjusted according to the individual. Visual function testing is very sensitive to position. In small equipment, due to the magnification relationship, the position error of the visual function training target is limited to within 0.1mm. However, the stepper motor has the problem of losing step, so that the target screen may not be able to accurately reach the target position after a single pulse command is issued, which greatly reduces the efficacy of the whole machine.

[0003] In order to improve the problem of motor out of step, the existing technology usually selects higher resolution motors, calculates the torque of the load, controls acceleration and other technical means to solve the above technical problems. Although this method alleviates the error problem to a certain extent, it is not only costly, but also cannot completely solve the error problem caused by out of step, which is always a temporary solution. Utility Model Content

[0004] The utility model overcomes the shortcomings of the prior art and provides a sight mark screen displacement control device.

[0005] The purpose of the utility model is achieved through the following technical solutions.

[0006] A sight mark screen displacement control device comprises a base, a sight mark screen and a driving device. The sight mark screen is slidably arranged on the guide rail of the base. The sight mark screen and the driving device are matched. A moving grid is fixed on the sight mark screen. The moving grid matches a fixed grid arranged along the sliding track of the sight mark screen.

[0007] The driving device comprises a driving motor and a driving screw rod. The driving motor is connected with the driving screw rod through a gear set, and the driving screw rod is connected with the sight mark screen.

[0008] One or more shaft seats are arranged on the base, a driving screw is arranged on the shaft seat, a transmission gear is fixedly arranged on the driving screw, and the transmission gear is meshedly connected with an output gear arranged on the rotor of the driving motor.

[0009] The driving motor is fixedly arranged on the base.

[0010] A control mainboard is arranged on the base, and the control mainboard is connected with the driving device, the moving grid and the fixed grid circuit.

[0011] The control main board is connected to the VCC pin of the moving gate through the pin VDD, the control main board is connected to the negative pole GND of the moving gate module through the pin VSS, the clock unit of the control main board is connected to the SCLK unit of the moving gate through the pin PA3, the decoder unit of the control main board is connected to the SDATA unit of the moving gate through the pin PA4, and the control main board is connected to the CLEAR unit of the moving gate through the pin PA2.

[0012] The negative pole GND of the moving gate module is set as grounding.

[0013] The driving motor is a stepper motor, and the stepper motor driving module adopts a two-phase four-wire stepper motor driving chip.

[0014] The MS1, MS2 and MS3 pins of the stepper motor driver chip correspond to the PC11, PC12 and PC12 pins of the control main board respectively. Low-capacitance bidirectional diodes connected to GND are respectively arranged on the paths between the MS1 pin and the PC11 pin, the MS2 pin and the PC12 pin, and the MS3 pin and the PC12 pin.

[0015] The STEP pin of the stepper motor driver chip is connected to the PB1 pin of the control motherboard, the DIR pin of the stepper motor driver chip is connected to the PC9 pin of the control motherboard, and the 1B pin, 1A pin, 2B pin and 2A pin of the stepper motor driver chip are connected to the corresponding four leads of the two-phase four-wire stepper motor through the interface.

[0016] The beneficial effects of the utility model are:

[0017] This solution uses a displacement sensing module to coordinately control the displacement of the motor. A closed-loop control method is formed, and the specific position of the target screen is compensated and controlled through the displacement sensing of the capacitive grid sensor. Capacitive grid displacement sensors are mainly used in the reading of physical dimensions of digital display vernier calipers. They have outstanding characteristics such as small size, simple structure, high resolution and accuracy, fast measurement speed, low power consumption, low cost, and low requirements for the use environment. This device is equipped with a capacitive grid sensor to measure mechanical displacement, which can not only achieve high accuracy, but also has relatively low cost and small size, and is extremely suitable for the manufacture of lightweight and high-precision systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a horizontal decomposition structure diagram of the utility model;

[0019] Figure 2 It is a longitudinal exploded structural diagram of the utility model;

[0020] Figure 3 It is the work flow chart of the utility model:

[0021] Figure 4It is the operation logic diagram of the utility model;

[0022] Figure 5 It is a circuit connection schematic diagram of the utility model;

[0023] Figure 6 This is the pin circuit diagram of the control mainboard of the utility model;

[0024] Figure 7 This is the circuit diagram of the stepper motor drive module of the utility model;

[0025] In the figure: 1. base; 2. guide rail; 3. shaft seat; 4. transmission gear; 5. output gear; 6. drive motor; 7. drive screw; 8. sight mark screen; 9. moving grid; 10. fixed grid. DETAILED DESCRIPTION

[0026] The technical solution of the utility model is further described below through specific embodiments.

[0027] Example

[0028] A sight mark screen displacement control device comprises a base 1, a sight mark screen 8 and a driving device. The sight mark screen 8 is slidably arranged on a guide rail 2 of the base 1, the sight mark screen 8 is matched with the driving device, a moving grid 9 is fixedly arranged on the sight mark screen 8, and the moving grid 9 matches with a fixed grid 10 arranged along the sliding track of the sight mark screen 8.

[0029] The driving device comprises a driving motor 6 and a driving screw 7 . The driving motor 6 is connected to the driving screw 7 via a gear set, and the driving screw 7 is connected to the sight mark screen 8 .

[0030] One or more shaft seats 3 are arranged on the base 1 , a driving screw 7 is arranged on the shaft seat 3 , a transmission gear 4 is fixedly arranged on the driving screw 7 , and the transmission gear 4 is meshedly connected with an output gear 5 arranged on the rotor of the driving motor 6 .

[0031] The driving motor 6 is fixedly arranged on the base 1 .

[0032] A control mainboard is provided on the base 1 , and the control mainboard is connected to the driving device, the moving grid 9 and the fixed grid 10 circuits.

[0033] The control main board is connected to the VCC pin of the moving gate 9 through the pin VDD, the control main board is connected to the negative pole GND of the moving gate 9 module through the pin VSS, the clock unit of the control main board is connected to the SCLK unit of the moving gate 9 through the pin PA3, the decoder unit of the control main board is connected to the SDATA unit of the moving gate 9 through the pin PA4, and the control main board is connected to the CLEAR unit of the moving gate 9 through the pin PA2.

[0034] The negative pole GND of the moving gate 9 module is set to ground.

[0035] The driving motor 6 is a stepping motor, and the stepping motor driving module adopts a two-phase four-wire stepping motor driving chip.

[0036] The MS1, MS2 and MS3 pins of the stepper motor driver chip correspond to the PC11, PC12 and PC12 pins of the control main board respectively. Low-capacitance bidirectional diodes connected to GND are respectively arranged on the paths between the MS1 pin and the PC11 pin, the MS2 pin and the PC12 pin, and the MS3 pin and the PC12 pin.

[0037] The STEP pin of the stepper motor driver chip is connected to the PB1 pin of the control motherboard, the DIR pin of the stepper motor driver chip is connected to the PC9 pin of the control motherboard, and the 1B pin, 1A pin, 2B pin and 2A pin of the stepper motor driver chip are connected to the corresponding four leads of the two-phase four-wire stepper motor through the interface.

[0038] like Figure 1 and Figure 2 As shown, the working principle of the utility model is as follows: in this embodiment, the driving device uses a driving motor 6 to drive the sight mark screen 8 to move, and the driving motor 6 uses a stepping motor, and the moving grid 9 and the fixed grid 10 cooperate with each other to monitor and compensate the actual position of the sight mark screen 8 in real time. The device controls the driving motor 6 through the stepping motor driving module by the control main board to drive the driving screw 7 to rotate, so as to realize the change of the position of the sight mark screen 8.

[0039] During use, the fixed grid 10 of the capacitive grid displacement sensor is fixedly arranged on the base 1, and the movable grid 9 moves along with the sight mark screen 8 to realize displacement sensing.

[0040] like Figure 3 and Figure 4 As shown in the figure, the signal processing circuit of the capacitive displacement sensor includes a signal amplifier, a phase comparator and a microprocessor. The moving gate 9 of the sensor transmits 8 driving signals, and the phase difference between each signal is π / 4; the fixed gate 10 reflects the signal, and the signal is amplified and analyzed by the phase comparator to determine the displacement. The control motherboard is responsible for receiving the displacement data from the capacitive displacement sensor, processing the data and comparing it with the preset target position. The control motherboard executes the algorithm through the built-in microprocessor to calculate the number of pulses that the stepper motor needs to adjust, and then sends the corresponding control signal through the stepper motor driver module to achieve precise control of the screen position.

[0041] Through the above-mentioned compensation adjustment method, the position of the sight mark screen 8 can be accurately controlled and the error can be controlled within 0.1mm, so that the visual function training process can better adapt to the objective needs of different patients for training and further improve the therapeutic effect of the visual function training device.

[0042] Further, if Figure 5 As shown, the control mainboard is connected to the VCC unit of the moving gate module through the pin VDD for power supply, the control mainboard is connected to the CLEAR unit of the moving gate module through the pin PA2 to realize clear control, the control mainboard is connected to the negative electrode GND of the moving gate module through the pin VSS, and the negative electrode GND of the moving gate module adopts a metal grounding setting to ensure data stability, the clock unit of the control mainboard is connected to the SCLK unit of the moving gate module through the pin PA3, and the decoder unit of the control mainboard is connected to the SDATA unit of the moving gate module through the pin PA4 for decoding the transmitted data.

[0043] like Figure 6 and Figure 7 As shown, the stepper motor drive module uses a two-phase four-wire stepper motor drive chip, which can convert the control information of the main control board on the stepper motor in the form of PWM waves into the control method required by the stepper motor, and provide a larger voltage and current for the stepper motor rotation that the control motherboard cannot provide. The MS1, MS2, and MS3 pins of the chip are respectively connected to the PC11, PC12, and PC10 pins of the control motherboard, which are used to set the subdivision of the stepper motor drive chip, weaken or eliminate the low-frequency vibration of the stepper motor, and connect to GND through a low-capacitance bidirectional diode to play a role in electrostatic protection; the STEP pin of the chip is connected to the PB1 pin of the control motherboard, which is used to control the motherboard to control the start, stop, and speed of the stepper motor rotation; the DIR pin of the chip is connected to the PC9 pin of the control motherboard, which is used to control the motherboard to control the rotation direction of the stepper motor; the 1B, 1A, 2B, and 2A of the chip are connected to the four leads corresponding to the two-phase four-wire stepper motor through the interface, which is used for the chip to control the rotation of the stepper motor; the other pins are connected as shown in the figure.

[0044] The above is a detailed description of the embodiments of the utility model, but the contents are only preferred embodiments of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. A sight mark screen displacement control device, Features: The sight mark screen comprises a base, a sight mark screen and a driving device. The sight mark screen is slidably arranged on the guide rail of the base. The sight mark screen is matched with the driving device. A moving grid is fixed on the sight mark screen. The moving grid matches with a fixed grid arranged along the sliding track of the sight mark screen.

2. A sight mark screen displacement control device according to claim 1, Features: The driving device comprises a driving motor and a driving screw, the driving motor is connected with the driving screw through a gear set, and the driving screw is connected with the sight mark screen.

3. A sight mark screen displacement control device according to claim 2, Features: One or more shaft seats are arranged on the base, the driving screw is arranged on the shaft seat, a transmission gear is fixedly arranged on the driving screw, and the transmission gear is meshedly connected with an output gear arranged on the rotor of the driving motor.

4. A sight mark screen displacement control device according to claim 2, Features: The driving motor is fixedly arranged on the base.

5. The sight mark screen displacement control device according to claim 1, Features: A control mainboard is arranged on the base, and the control mainboard is connected with the driving device, the moving grid and the fixed grid circuit.

6. A sight mark screen displacement control device according to claim 5, Features: The control main board is connected to the VCC pin of the moving gate through the pin VDD, the control main board is connected to the negative pole GND of the moving gate module through the pin VSS, the clock unit of the control main board is connected to the SCLK unit of the moving gate through the pin PA3, the decoder unit of the control main board is connected to the SDATA unit of the moving gate through the pin PA4, and the control main board is connected to the CLEAR unit of the moving gate through the pin PA2.

7. A sight mark screen displacement control device according to claim 6, Features: The negative electrode GND of the moving gate module is grounded.

8. The sight mark screen displacement control device according to claim 2, Features: The driving motor is a stepping motor, and the stepping motor driving module adopts a two-phase four-wire stepping motor driving chip.

9. A sight mark screen displacement control device according to claim 8, Features: The MS1, MS2 and MS3 pins of the stepper motor driver chip correspond to the PC11, PC12 and PC12 pins of the control main board respectively. Low-capacitance bidirectional diodes connected to GND are respectively arranged on the paths between the MS1 pin and the PC11 pin, the MS2 pin and the PC12 pin, and the MS3 pin and the PC12 pin.

10. The sight mark screen displacement control device according to claim 8, Features: The STEP pin of the stepper motor driver chip is connected to the PB1 pin of the control motherboard, the DIR pin of the stepper motor driver chip is connected to the PC9 pin of the control motherboard, and the 1B pin, 1A pin, 2B pin and 2A pin of the stepper motor driver chip are connected to the corresponding four leads of the two-phase four-wire stepper motor through the interface.

Images