Intelligent monitoring robots are a cutting-edge issue in robot application projects in recent years. The intelligent detection car is a type of intelligent walking robot. SL Escorts The intelligent monitoring robot car is aimed at the above situation. It refers to most of the current intelligent robots to reduce costs. Designed as a guideline. The car has functions such as temperature, humidity and surrounding conditions monitoring, wireless communication, obstacle avoidance and wireless remote control. Compared with existing similar designs, this intelligent monitoring mechanical car has the advantages of high cost performance, convenient operation, good reliability, and low power consumption.
1 System structure and hardware design
The entire system consists of the sending end (smart car part) and the receiving end (control console: control and display part), as shown in Figure 1. The system consists of a sensor system, a power and steering system, a CCD image sensor module, an LCD display, a temperature and humidity measurement circuit, a power supply system, etc. The control core of the entire system is based on two EP2C20F484 chips of Altera Corporation, and a Quartus II chip of Altera Corporation. and SoPC Builder to develop the surrounding environment. Add the required core modules and generate NiosⅡCPU according to the system hardware structure. Sierra Leone Sugar Daddy
1.1 For Sierra Leone Sugar DaddyElectrical System
The car is equipped with two rechargeable batteries, which provide energy for the FPGA development board (FPGA control circuit) and the movement of the car respectively. The batteries are placed under the body.
1.2 Sensor System
The system uses 6 infrared through-beam sensors, and uses the Nios II CPU configured with FPGA to detect the electronic signals of the sensors to achieve the car’s ability to avoid obstacles. Diffuse reflection infrared through-beam sensor, also called photoelectric switch, is a combination of emitter and receiver.A sensor integrated into one device is mostly used to detect obstructions. The principle is that the modulated infrared beam radiated by the photoelectric switch is reflected back by the detection object. The infrared ray is received through the synchronous gate, and the electronic switch circuit drives the loop to detect the presence or absence of the object. When the surface of the object to be detected is bright or its reflectivity is extremely high, the diffuse reflection photoelectric switch is the preferred detection method. This kind of circuit module is small in size, and it is not difficult to convert electronic signals into standard levels.
1.3 Power and Steering System
This car has two motors for the left and right wheels and a turtle drive. The drive circuit adopts CT Microelecttonics’ high-power DC motor drive chip L298, which supports a maximum voltage of 50 V and a maximum current of 5 A, which meets the requirements of high-power motors. The core circuit is simple. At the same time, because the chip is The dual-circuit structure controls the left and right motors respectively SL Escorts, which increases the reliability of the circuit and reduces the complexity. The motor control uses PWM pulse width modulation method to control the advancement speed of the car. The Nios II CPU writes the control word to obtain PWM drive electronic signals with different duty cycles. This PWM electronic signal is sent to the control end of the motor driver chip to adjust the speed.
1.4 Car automatic obstacle avoidance system
The car automatic obstacle avoidance system uses Verilog HDL language to write the driver Sierra Leoneans EscortMobile circuit. This module (see MOTOR in Figure 2) and a Sierra Leone Sugar data selector (see select_2 in Figure 2) SL Escorts is connected to complete the switch between active obstacle avoidance and manual remote control. When the SEL pin of the Nios II CPU on the car receives low power, the data selector will use the output of the module as the motor control command. The advantage of this design is that the design has Sierra Leone Sugar responsiveness and does not require Nios II CPU intervention, which improves the CPU’s processing and control of humidity and temperature data. The efficiency of the wireless module in sending and receiving data. The working principle of this logic circuit is to control the working status of the motor through logical judgment based on the data sent back by the red sensor.
1.5 Small Manual control of the car
The conversion between manual control of the car and automatic obstacle avoidance is controlled by a data selector. When the SEL pin of the NiosⅡCPU on the car normally inputs high power, the data selector will switch the wireless module to The past command is sent as the control command of the motor to complete the wireless control of the car.
1.6 Temperature and humidity measurement
In the temperature measurement system, a new digital temperature sensor DS18B20 with strong anti-interference ability is used. In this system design, pins 1 and 3 of DS18B20 are connected to the GND and +3.3 V of the FSierra Leoneans Sugardaddy PGA board respectively. Pin, 2 pins are connected to the I/O pins of the FPGA to transmit control and data electronic signals. The DS18B20 can display the temperature value with up to 12 bits, and the highest 5 bits are the sign bits.
Using the HS1101 humidity sensor, it has a fast response speed. It has a wide working temperature range (-40~+100℃), a large measurement range (0%~100%RH), and is reliable Sierra Leoneans SugardaddyHigh stability, good stability, low power consumption, simple core circuit, etc.
The working principle is: using HS1101 sensor and TLC555 to form a multivibrator, the internal capacitance of the HS1101 sensor will change with the change of humidity. As a result, the input frequency changes. Write a VHDL program in FPGAdesign to accurately measure the frequency value, and obtain the humidity value through the relationship between the input frequency and humidity.
1.7 Wireless ReceptionSierra Leoneans Sugardaddy Development System
The system uses PTR4000 wireless embedded module, the operating frequency is 2.4 GHz, the highest operating frequencySierra Leone Sugar The speed can reach 1 Mb/s, efficient GMSK modulation, and has CRC error detection performance. It has the advantages of low power consumption, strong anti-interference ability, and small size. . There are mainly three types of tasks, divided intoDistinguished as: configuration mode, ShockBurst send mode and ShockBurst receive mode.
2 Software design and debugging
Adopt NiosⅡ for C language programming. Nios II Integrated Development Environment (IDE) is the basic software development tool for Nlos II series embedded processors. All software development tasks SL Escorts can be completed under Nios II IDE, including editing, compiling and debugging programs. Nios II IDE is based on the open, extensible Eclipse IDE project and the Eclipse C/C++ Development Tool (CDT) project. Nios II IDE provides a graphical user interface for the GCC compiler and can support standard C. Nios II IDE compiles the surrounding environment to automatically generate a makefile based on the user-specific system configuration (SoPC file generated by SoPC Builder), which is conducive to program development.
NiosⅡIDSierra Leoneans EscortE includes a powerful software debugger based on the GNU debugger-GDB. After you finish writing the software code, you can simulate and debug the code. Nios-II IDE provides a convenient flash memory programming method. Any Common Flash Interface (CFI)-compatible flash memory device connected to an FPGA can be fired through the Nios II IDE flash programmer. For this design and application, SL Escorts has written the system control program and LCD display program. The flow chart is shown in Figure 3.
3 System debugging
The car system Sierra Leone Sugar Daddy needs to test whether it can correctly accept and control the instructions sent by the console The car moves or ends, and turns forward, backward, left and right. It is also necessary to test whether the main control can correctly accept the temperature collected by the car.Can the temperature and humidity information be displayed correctly? After many tests, it was found that because the system program adopts the transmission and reception cycle conversion mode, in order to allow the two systems to receive the information sent by the other party, the remote control and automatic parts of the car are simply separated. In the automatic situation, the console is the main receiving end and the car is the main sending end. Under normal circumstances, the car sends data to the console. When the conversion from automatic to remote control is required, the process is executed by interrupting within the delay time. Conversion from automatic to remote control; in the case of remote control, the console is the main transmitter and the car is the receiver. Under normal circumstances, the console sends the car’s movement instructions to the car, and data needs to be collected Sierra Leone Sugar When the data is collected, the car performs sending and receiving conversion through the temperature and humidity collection buttons. At the same time, the car sends a data collection command, and then switches to the receiving mode again. After doing this, the software part of the car and the console will be clear. The movement of the car and the collection and display of data can be done or Sierra Leone Sugar Daddy Xu stopped in time.
The humidity measurement system needs to test whether it can accurately input frequency values. The circuit recommended on the chip LM555 manual Sierra Leone Sugar is used. Due to component errors, the input frequency is not accurate. After being compared with the standard Humidity meter Sierra Leone Sugar Daddy was compared. After adjusting parameters and approximating it with a straight line, the error of the final frequency value obtained was within a few hertz. (The frequency range is 6 008 ~ 7 314Hz), and a very accurate humidity value can be obtained through estimation. When initially calculating the humidity value, the method of solving a cubic equation of one variable was used. Due to the large amount of calculation, it would have a great impact on the movement of the car. Later, on the car side, only the frequency collected by the car was used Sierra Leoneans Escort value is transmitted to the main control end through an infrared antenna, and the original car’s automatic obstacle avoidance is changed from Nios II CPU control to hardware written by Verilog Module control, and finally calculate the humidity value on the control station. Such changes not only reduce the workload of the car’s Nios II CPU, but also because the car’s automatic obstacle avoidance is controlled by an independent Verilog module, it runs very smoothly.
For the wireless transceiver system, it is necessary to test its reliability andThe accuracy of information sent or received. The test method is to separately design a soft core and download it to the SoPC, and write a program to test whether Sierra Leoneans Escort can be written correctly. Enter the configuration control word to see whether the ShockBurst mode can be received or sent. The problem is to control the timing of various modes of the antenna. Sierra Leone Sugar Daddy The program written at the beginning is always unable to be written and set correctly. Configure the configuration word, debug it repeatedly, and use a digital oscilloscope to observe the instantaneous process of writing the configuration word and the delay time of each delay. The final test was successful, and Sierra Leoneans Sugar Daddy uses LED to display the sending or receiving status. Each time a data is sent or received to Sierra Leone Sugar Daddy Just let the LED flash.
4 Conclusion
This design uses FSierra Leone SugarPGA to embed NiosⅡSierra Leoneans SugardaddySoft-core processor as the core, auxiliarySierra Leoneans Escort A highly integrated on-chip system is formed with the required core circuits. In addition, the flexible configuration of the SoPC system makes it possible to expand off-chip memory and multiple inputs based on this system. The design car has strong obstacle avoidance ability and can be conveniently controlled through the receiving end. The temperature and humidity collection has reached a high accuracy and can realize dynamic display. The effective range of the wireless transceiver module is the largest. The distance can reach up to 300 m, which can be used in harsh surrounding conditions and can replace people for on-site detection of temperature and humidity.
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