Double-shaft holder system based on Bluetooth remote control

Abstract

The invention discloses a double-shaft holder system based on Bluetooth remote control, and relates to a double-shaft holder system. The invention aims to solve the problem that the traditional manual operation, low-precision and single-axial holder control method cannot meet the modern requirements of an intelligent video monitoring system on high-efficiency and high-precision control. A main control chip is used for communicating with a Bluetooth module, receiving a control signal and generating a corresponding pulse sequence according to the signal to control rotation of a stepping motor module; the Bluetooth module communicates with the main control chip through a serial port; the stepping motor is used for adjusting the angle of the double-shaft holder; the motor driving circuit is used for amplifying a control signal output by the main control chip and providing enough current and voltage to drive the stepping motor module; the sensor module is used for monitoring and displaying a yaw angle and a pitch angle of the holder and feeding back information of the yaw angle and the pitch angle to the main control chip; the battery module is used for providing power support for the whole system. The invention belongs to the technical field of electronic equipment.

Description

Technical Field

[0001] The present invention relates to a two-axis pan-tilt system, belonging to the technical field of electronic devices. Background Art

[0002] In order to broaden the field of view of a camera and reduce the number of cameras required to be arranged in a certain specific area, cameras equipped with a pan-tilt are commonly used nowadays. Through a remote client, monitoring personnel can flexibly control the rotation of the pan-tilt, thereby effectively expanding the monitoring coverage area, quickly positioning stationary targets, and fulfilling the requirement of environmental monitoring for a large range. The progress of computer vision technology has made intelligent video monitoring a hot topic in the research field. The system can autonomously complete the recognition and tracking of moving targets by applying advanced technologies of image processing and video analysis. Due to the development of these technologies, the traditional manual operation, low-precision, and single-axis pan-tilt control methods can no longer meet the modern requirements of high efficiency and high precision control of intelligent video monitoring systems. Therefore, the pan-tilt control technology needs to be innovated and upgraded to adapt to these new requirements. Summary of the Invention

[0003] The present invention aims to solve the problem that the traditional manual operation, low-precision, and single-axis pan-tilt control methods can no longer meet the modern requirements of high efficiency and high precision control of intelligent video monitoring systems, and further proposes a two-axis pan-tilt system based on Bluetooth remote control.

[0004] The technical solution adopted by the present invention to solve the above problems is as follows: The present invention includes a main control chip, a Bluetooth module, a stepper motor module, a motor drive circuit, a sensor module, and a battery module;

[0005] The main control chip is used to communicate with the Bluetooth module, receive control signals, and generate corresponding pulse sequences according to the signals to control the rotation of the stepper motor module;

[0006] The Bluetooth module communicates with the main control chip through a serial port;

[0007] The stepper motor is used to adjust the angle of the two-axis pan-tilt;

[0008] The motor drive circuit is used to amplify the control signals output by the main control chip and provide sufficient current and voltage to drive the stepper motor module;

[0009] The sensor module is used to monitor and display the yaw angle and pitch angle of the pan-tilt, and feed back the yaw angle and pitch angle information to the main control chip;

[0010] The battery module is used to provide power support for the entire system.

[0011] Further, the main control chip is an stm32 main control chip.

[0012] Further, the Bluetooth module is an HC-05 type Bluetooth module.

[0013] Further, the process of the main control chip communicating with the Bluetooth module through the serial port is as follows:

[0014] Initialize the serial port and set parameters; receive data from the Bluetooth module by means of interrupt or polling; parse the received data to extract the control instruction information therein.

[0015] Further, the set parameters include baud rate, data bits, stop bits and parity bits.

[0016] Further, the timer of the main control chip generates a pulse sequence to drive the stepper motor module. The main control chip adjusts the speed of the stepper motor module by adjusting the frequency of the pulses, and the main control chip changes the direction of the stepper motor module by changing the order of the pulses.

[0017] The beneficial effects of the present invention are as follows: The present invention has high performance and high sensitivity, and can achieve precise control of the two axes of the pan-tilt through Bluetooth signals; the present invention can ensure that the pan-tilt shows high precision, sensitivity and stable performance during operation, so as to meet the expected standards of the system design; through the control of Bluetooth technology, the operation of the present invention is more convenient, and at the same time, the system stability is enhanced;

[0018] The present invention uses stm32 as the main control chip. Its rich peripheral resources and powerful processing ability make the control of the stepper motor more precise; compared with some solutions using low-end microcontrollers, the high-precision timer inside stm32 can generate a pulse sequence more precisely, so as to realize the fine control of the speed, direction and rotation angle of the stepper motor; whether it is to fine-tune the azimuth angle or pitch angle of the pan-tilt, higher precision can be achieved, which is crucial for application scenarios that require high-precision positioning (such as professional photography, precision measurement sensor mounting, etc.);

[0019] Compared with some solutions on the market that use ordinary DC motors combined with encoder feedback, the stepper motor of the present invention can accurately control the rotation angle by directly controlling the input pulses, reducing the accuracy loss caused by encoder errors or complex feedback control algorithms; this design based on stepper motors can ensure that the pan-tilt maintains extremely high accuracy during multiple repeated positioning processes;

[0020] The present invention uses an HC-05 Bluetooth module for remote control communication; HC-05 is a Bluetooth serial communication module with stable performance and excellent performance in communication stability; compared with some solutions of low-quality Bluetooth modules, it can ensure stable and high-speed data transmission within a certain range, reducing the problems of loss or error of control instructions caused by signal loss or interference; moreover, its slave mode is easy to set up and connect to external devices (such as mobile phones), enabling users to conveniently remote control the pan-tilt head through common mobile devices without additional complex remote control devices;

[0021] In the design of the motor drive circuit of the present invention, protection functions such as overcurrent and over-temperature are considered; this is ignored by many simple pan-tilt head solutions on the market; when abnormal situations such as motor jamming occur, it can protect the motor and the entire system in a timely manner, avoiding damage caused by long-term overload operation of the motor, and greatly improving the reliability and service life of the system. Brief Description of the Drawings

[0022] Figure 1 It is a flow chart of the main control chip driving the stepper motor module. Detailed Embodiments

[0023] Detailed Embodiment 1: A two-axis pan-tilt head system based on Bluetooth remote control, including a main control chip, a Bluetooth module, a stepper motor module, a motor drive circuit, a sensor module, and a battery module;

[0024] The main control chip is used to communicate with the Bluetooth module, receive control signals, and generate corresponding pulse sequences according to the signals to control the rotation of the stepper motor module;

[0025] The Bluetooth module communicates with the main control chip through a serial port;

[0026] The stepper motor is used to adjust the angle of the two-axis pan-tilt head;

[0027] The motor drive circuit is used to amplify the control signals output by the main control chip and provide sufficient current and voltage to drive the stepper motor module;

[0028] The sensor module is used to monitor and display the yaw angle and pitch angle of the pan-tilt head, and feedback the yaw angle and pitch angle information to the main control chip;

[0029] The battery module is used to provide power support for the entire system.

[0030] Among them, the main control chip is an STM32 main control chip; the main control chip is soldered on the PCB main board and is equipped with a power supply circuit at the same time. The power supply circuit includes a voltage regulator, which converts the externally input power supply into a stable voltage required by the main control chip; multiple pin interfaces are reserved on the PCB board for connecting a Bluetooth module, a motor drive circuit, and other possible expansion interfaces, and a reset circuit is designed to ensure that the chip can be normally reset when needed.

[0031] The Bluetooth module is an HC-05 type Bluetooth module. Connect the HC-05 Bluetooth module to the corresponding UART interface of the STM32 through the serial port pins (TX, RX); at the same time, connect the power supply pins for the Bluetooth module to ensure that the power supply voltage is stable within its operating voltage range.

[0032] Connect the input pins of the driver chip of the drive circuit to the GPIO pins of the STM32. These pins will be used to output control pulse signals; connect the power supply pins of the drive chip, and select a suitable power supply according to the power requirement of the motor; connect the two stepper motors to the output ends of the corresponding motor drive chips respectively; ensure that the wiring of the motors is correct, including the phase sequence connection of the motors, to ensure that the motors can rotate in the expected direction; for the fixation of the motors, select a suitable mounting bracket and firmly mount the motors on the dual-axis structure of the pan-tilt to ensure that the motor shaft is concentric with the pan-tilt rotation shaft.

[0033] The process of serial communication between the main control chip and the Bluetooth module is as follows:

[0034] Initialize the serial port and set parameters; receive data from the Bluetooth module by means of interrupt or polling; analyze the received data and extract the control instruction information therein.

[0035] The set parameters include baud rate, data bits, stop bits, and parity bits.

[0036] Among them, the timer of the main control chip generates a pulse sequence to drive the stepper motor module. The main control chip realizes the speed control of the stepper motor module by adjusting the frequency of the pulses, and the main control chip realizes the steering control of the stepper motor module by changing the order of the pulses.

[0037] Among them, the timer inside the main control chip can be used to accurately control the frequency and duty cycle of the pulses to achieve accurate control of the speed and steering of the stepper motor. At the same time, it can also monitor the operating state of the motor, for example, detect the stall condition of the motor through the external interrupt pin to take protective measures in a timely manner.

[0038] The HC-05 works in slave mode, waiting to connect to an external Bluetooth master device (such as a mobile phone); once the connection is successful, it transmits the control instructions received from the master device to the stm32; its communication baud rate can be set as needed to ensure stable and high-speed data transmission; this module has the advantages of low power consumption and small size, and is suitable for use in this design.

[0039] Among them, the stepper motor has the characteristics of high precision and simple control. By controlling the number, frequency and sequence of input pulses, the rotation angle and speed of the motor can be accurately controlled. In this embodiment, one stepper motor is used for each of the two axes. One axis controls the horizontal rotation (azimuth angle) of the pan-tilt, and the other axis controls the pitch angle of the pan-tilt. When selecting the motor, parameters such as load capacity and step angle need to be considered to ensure normal operation of the pan-tilt under different load conditions.

[0040] Among them, the drive circuit also has a protection function, and the protection function includes overcurrent protection and overtemperature protection to improve the reliability of the system.

[0041] In order to achieve precise angle control, the number of pulses to be sent needs to be calculated based on the step angle of the stepper motor and the target angle. During the operation of the motor, the state of the motor also needs to be monitored in real time. For example, by detecting the motor current or the number of steps to determine whether the motor is operating normally. If an abnormal situation (such as stalling) occurs, the motor operation is stopped in time and corresponding treatment measures are taken.

[0042] The main program of the present invention is responsible for coordinating the operation of the Bluetooth communication program and the stepper motor control program. It first initializes the system, including initializing the peripherals of the stm32, the Bluetooth module and the motor drive circuit, etc.; then enters the main loop, and continuously detects whether there are new Bluetooth connections and control instructions in the main loop; when a control instruction is received, the stepper motor control program is called to drive the motor to run to achieve the angle adjustment of the pan-tilt; at the same time, the main program can also add some other functions as needed, such as system status display, fault diagnosis, etc.

[0043] Working principle

[0044] Bluetooth communication function

[0045] Initialize serial communication in the software, set the baud rate to a value matching the HC-05 module, and at the same time set parameters such as data bits, stop bits and parity bits; write a serial port receive interrupt service function, which is triggered when data is received from the Bluetooth module; in the interrupt service function, read the received data and store it in the buffer; write a data parsing function to analyze the data in the buffer and extract the control instructions; for example, it is agreed that specific byte sequences represent the rotation direction and angle of the horizontal axis of the pan-tilt, and other byte sequences represent the control information of the pitch axis.

[0046] Stepper motor module control function

[0047] Using the timer function of stm32, write a timer initialization function. According to the required motor speed and step angle, calculate the prescaler value and reload value of the timer to generate a pulse signal with an appropriate frequency. For example, if the step angle of the stepper motor is 1.8°, and a speed of 60 revolutions per minute is to be achieved, then calculate the number of pulses generated per second, and then configure the timer. Write a function to control the start, stop, change of pulse frequency, duty cycle, etc. of the timer according to the control instructions parsed from the Bluetooth communication. For the steering control of the motor, it is achieved by changing the order of the output pulses. For example, for a four-phase stepper motor, changing the phase sequence can achieve forward and reverse rotation. At the same time, write a function to calculate the number of pulses to be output according to the target angle to achieve precise angle control.

[0048] System integration and optimization

[0049] In the main function, first call the system initialization function, including the initialization of the stm32 chip, Bluetooth communication initialization, and motor drive initialization, etc.; then enter the main loop, and continuously check whether there are new Bluetooth control instructions in the main loop; when an instruction is received, call the motor control function to drive the motor to rotate to achieve the angle adjustment of the pan-tilt head. At the same time, add an exception handling mechanism in the software. For example, when it is detected that the motor current increases abnormally (possibly a stall situation), immediately stop the motor operation and send a fault message to the user via Bluetooth. In addition, some optimization algorithms can also be added, such as smoothing the motor control pulses to reduce the vibration and noise during motor operation.

[0050] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to be equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention and is based on the technical essence of the present invention, any simple modification, equivalent replacement, and improvement of the above embodiments are still within the protection scope of the technical solution of the present invention.

Claims

1. A two-axis pan-tilt system based on Bluetooth remote control, characterized in that, It includes a main control chip, a Bluetooth module, a stepper motor module, a motor drive circuit, a sensor module, and a battery module; The main control chip is used to communicate with the Bluetooth module, receive control signals, and generate corresponding pulse sequences according to the signals to control the rotation of the stepper motor module; The Bluetooth module communicates with the main control chip through a serial port; The stepper motor is used to adjust the angle of the two-axis gimbal; The motor drive circuit is used to amplify the control signals output by the main control chip and provide sufficient current and voltage to drive the stepper motor module; The sensor module is used to monitor and display the yaw angle and pitch angle of the gimbal and feedback the yaw angle and pitch angle information to the main control chip; The battery module is used to provide power support for the entire system.

2. The dual-axis pan-tilt system based on Bluetooth remote control according to claim 1, characterized in that, The main control chip is an stm32 main control chip.

3. A two-axis pan-tilt system based on Bluetooth remote control according to claim 1, characterized in that, The Bluetooth module is an HC-05 type Bluetooth module.

4. A two-axis pan-tilt system based on Bluetooth remote control according to claim 1, characterized in that, The process of serial communication between the main control chip and the Bluetooth module is as follows: Initialize the serial port and set parameters; receive data from the Bluetooth module through interrupt or polling; parse the received data and extract the control instruction information therein.

5. The dual-axis pan-tilt system based on Bluetooth remote control according to claim 4, wherein The set parameters include baud rate, data bits, stop bits, and parity bits.

6. A two-axis pan-tilt system based on Bluetooth remote control according to claim 1, wherein, The timer of the main control chip generates a pulse sequence to drive the stepper motor module. The main control chip realizes the speed control of the stepper motor module by adjusting the frequency of the pulses, and realizes the steering control of the stepper motor module by changing the order of the pulses.

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