Design and implementation of a six-degree-of-freedom automatic tracking robot based on single-chip microcomputer control

One of the characteristics of the development of contemporary science and technology is the combination of mechanical technology, electronic technology and information technology. Robots are one of the products of this combination. Modern robots are all developed from machinery. The difference from traditional machines is that robots have computer control systems, so they have certain intelligence. Humans can compile action programs to enable them to perform various actions. The six-degree-of-freedom automatic tracking and handling robot is one of them. This kind of handling robot can not only replace certain functions of humans, but sometimes even exceed the physical ability of humans. It can be used 24 hours a day or even

It can operate continuously and repeatedly for longer periods of time and can withstand various harsh environments. Therefore, the handling robot is an extension and development of the local functions of the human body.

This design mainly uses the single-chip microcomputer MSP430 as the control core, and combines the DC motor, pyroelectric infrared sensor, etc. It gives full play to the performance of the single-chip microcomputer, and its advantages are simple hardware circuit, perfect software function, reliable control system, high cost performance, etc. It has certain use and reference value.

1 System Principle

1.1 System Principle of Automatic Tracking Module

The automatic tracking module in this design is mainly composed of a single-chip microcomputer and its external circuit, an infrared tracking circuit, a DC motor control circuit, etc. During normal operation, the single-chip microcomputer cyclically detects the output signal of the infrared tracking circuit and generates a DC motor control signal based on it. When the system detects that the working mode has changed, the system enters the corresponding mode. Its principle block diagram is shown in Figure 1 and Figure 2.

1.2 System principle of six-degree-of-freedom manipulator module

The system is designed in a modular way, dividing the machine into four parts: base, arm, wrist, and hand. The controller is based on the MSP430 microcontroller, and the specific control part block diagram is shown in Figure 3.

2 System Design

2.1 Automatic tracking module hardware design

1) Basic MCU system

The control core of the tracking robot system is generally based on the basic hardware resources in the MSP430 microcontroller, and some external devices are expanded when necessary. The control that needs to be completed in this design is relatively simple and can be fully realized with the basic hardware resources in the microcontroller, so there is no need to expand.

2) Amplifying signal circuit

It is controlled by LM324, which is a quad op amp integrated circuit. It uses a 14-pin dual in-line plastic package and contains four groups of identical operational amplifiers. Except for the shared power supply, the four groups of operational amplifiers are independent of each other.

3) Motor drive circuit

The motor used is a common DC motor. Under the control of the MSP430 microcontroller, a motor driver chip can be connected or other components can be used to make the motor rotate. In order to simplify the design of this system, other methods are used to replace the circuit driver chip.

2.2 Hardware design of six-DOF manipulator module

The six-degree-of-freedom manipulator is a robotic arm driven by six servo motors. In addition to the four joints that make up the arm and one joint in the wrist, plus the grip of the hand, the mechanical structure of a manipulator is realized.

The control module uses a 5 V DC power supply to power the microcontroller and the motor of the robotic arm respectively. The circuit includes a manual reset circuit, a crystal oscillator circuit, a matrix keyboard, an independent keyboard for controlling the rotation angle of the microcontroller, and a servo motor access port. The selected motor identification number and the rotation angle of the motor can be displayed on the display screen.

3 Software Design

The software design of this system is hardware-oriented and is programmed in C language. The most important part is the microcontroller controlling the motor rotation (including forward and reverse rotation), time delay and PID algorithm. The specific design flow chart is shown in Figure 4 and Figure 5.

4 System Debugging

1) After the program is written, check the code line by line carefully. Check the code for errors, create your own code checklist, and check the places where errors are often made. Check whether the code meets the programming specifications.

2) Debug the program to see if it can be simulated. If it runs normally, burn the program debugged in the compiler to the microcontroller.

3) When the power is connected, observe whether the overall circuit operates according to the expected design, whether the motor rotates forward, whether the motor rotates reversely, etc. The error part of the program can be inferred based on the operation of the circuit, and the program can be modified and burned into the microcontroller after being debugged by the compiler, and repeatedly tested until it can work completely normally.

5 Conclusion

This system is a single-chip tracking robot system, which mainly uses the single-chip MSP430 as the control core, and is combined with a DC motor, a servo, an integrated infrared receiver, etc. This system has simple hardware and software design, is easy to develop, and strictly controls the procurement cost of various components, so it is low-priced, safe, reliable, and easy to operate.