1. Introduction
Parts are deformed due to various heat effects during the processing, which leads to the destruction of the original processing accuracy or direct processing errors. For precision processing, the influence of thermal deformation is particularly significant, and the processing errors caused by this account for more than 40% of the total processing errors. This paper presents a system for accurately measuring the temperature of shaft parts. The system is controlled by the single-chip microcomputer 80C552, which is simple, reliable and accurate. At the same time, it can calculate the thermal deformation of the shaft at different temperatures.
2. Sensor composition and interface circuit
1. Sensor composition
The sensor uses a Pt temperature sensor, as shown in Figure 1.
Figure 1 Pt temperature sensor
This sensor is a coil wound by a platinum wire with a diameter of 30 microns, sandwiched between two layers of polyimide foil, and connected to the outside world through two nickel strips. It is only 0.3mm thick and is easy to use for temperature measurement of curved surfaces. It has very little heat loss and a large measurement area, achieving rapid response. In actual use, it is pasted on the inside of the arc-shaped magnet. When measuring the temperature, the magnet can be adsorbed on the shaft for use, which is convenient and quick. As shown in Figure 2 below:
Figure 2 Temperature sensor composition of measuring axis
2. Interface circuit
The signal sent from the temperature sensor enters the amplifier. The amplifier uses AD521 integrated measurement amplifier. This amplifier has the characteristics of high input impedance, low offset current, and high common mode rejection ratio. Its gain can be adjusted in the range of 0.1-1000. The gain adjustment does not require precise external resistors, and various gain parameters have been internally compensated. It can well suppress common mode interference and power supply voltage noise caused by power frequency, static electricity and electromagnetic coupling. Its amplification circuit principle is shown in Figure 3.
Figure 3 Schematic diagram of signal amplification circuit
Among them, pins 4 and 6 are external zero adjustment terminals, which can be connected to 10KΩ resistors and negative power supply zero adjustment. Pins 14 and 2 are external gain resistors, and pins 10 and 13 are external feedback resistors. The system has a zero error compensation function. When the single-chip microcomputer is working, the input terminal is grounded first. The non-zero data sent to the single-chip microcomputer through the measurement amplifier circuit, A/D and interface circuit is the zero error. And save the acquired zero-point error, and then take the difference between each collected data and the zero-point error as the effective sampling value to eliminate the zero-point error of the system.
3. System composition and measurement principle
The electrical principle of the system hardware is shown in Figure 4
Figure 4 System composition schematic diagram
The hardware part of the system is mainly composed of the front-end input circuit, the human-machine interface circuit, the CPU and the peripheral circuit. The required components are: the CPU uses PHILIPS 80C552, the EPROM is 2764, the sensor uses a PT temperature sensor (accuracy level is 0.5, the measurement range is -80℃--+180℃), AD521 measurement amplifier, 4 digital tubes, and a 4x4 keyboard. The
CPU uses PHLIPS80C552, and its pin arrangement has two ways, one is a 68-pin PLCC package, and the other is an 80-pin QFP80 package. The chip with the first arrangement is used here. Since the 80C552 has a 10-bit A/D converter inside, the hardware circuit omits the A/D converter, and can also obtain a higher resolution.
The system program mainly includes two parts, one is the system monitoring and management program, and the other is the sampling and measurement program.
The single-chip microcomputer is first initialized, and the initial state of the program is set to the running state. Except for entering the running state just after power-on, the program must judge the state flag bit in the future, and enter the programming or running state according to the judgment result. In the running state, the parameters cannot be edited, and the parameters can only be read out. The input signal is detected and the temperature value is displayed. Through key operation, the expansion and contraction amount of the measured axis is displayed. In the state of editing parameters, the system does not measure. When entering the programming state, it is required to enter the programming allowed password. On the premise that the password is entered correctly, the parameters can be set or modified through key operation, and the parameters are stored in the CPU.
The keyboard is a 4X4 row and column matrix, which can be configured with 16 keys. The 4-digit LED display is used to display the temperature value, and the decimal point is placed before the last digit. In order to save the hardware resources and time resources of the single-chip microcomputer I/O port and simplify the circuit, the LED display adopts a dynamic display mode. The segment selection line occupies an 8-bit I/O port, namely the P4 port, and the bit selection line occupies a 4-bit I/O port, namely the P3.4-P3.7 port. Since the segment selection lines of each bit are connected in parallel, the output of the segment selection code is the same for each bit. If each LED is to display the display character corresponding to the current bit, a scanning display method must be used, that is, at a certain moment, only the bit selection line of a certain bit is in the selected state, and the bit selection lines of other bits are in the closed state. At the same time, the segment selection line outputs the font code of the corresponding bit to display the character. That is, at a certain moment, only the selected bit of the 4-bit LED displays the character, and the other 3 bits are off.
IV. Conclusion
The system design adopts a more advanced design scheme, which improves the degree of digitization, can replace thermocouples for temperature detection, and ensures the reliability and stability of system detection. The use of other types of sensors can realize temperature measurement of different parts, which has good prospects.
Keywords：80C552
Reference address：Axis Parts Temperature Measurement System Based on 80C552 Single Chip Machine
Parts are deformed due to various heat effects during the processing, which leads to the destruction of the original processing accuracy or direct processing errors. For precision processing, the influence of thermal deformation is particularly significant, and the processing errors caused by this account for more than 40% of the total processing errors. This paper presents a system for accurately measuring the temperature of shaft parts. The system is controlled by the single-chip microcomputer 80C552, which is simple, reliable and accurate. At the same time, it can calculate the thermal deformation of the shaft at different temperatures.
2. Sensor composition and interface circuit
1. Sensor composition
The sensor uses a Pt temperature sensor, as shown in Figure 1.
Figure 1 Pt temperature sensor
This sensor is a coil wound by a platinum wire with a diameter of 30 microns, sandwiched between two layers of polyimide foil, and connected to the outside world through two nickel strips. It is only 0.3mm thick and is easy to use for temperature measurement of curved surfaces. It has very little heat loss and a large measurement area, achieving rapid response. In actual use, it is pasted on the inside of the arc-shaped magnet. When measuring the temperature, the magnet can be adsorbed on the shaft for use, which is convenient and quick. As shown in Figure 2 below:
Figure 2 Temperature sensor composition of measuring axis
2. Interface circuit
The signal sent from the temperature sensor enters the amplifier. The amplifier uses AD521 integrated measurement amplifier. This amplifier has the characteristics of high input impedance, low offset current, and high common mode rejection ratio. Its gain can be adjusted in the range of 0.1-1000. The gain adjustment does not require precise external resistors, and various gain parameters have been internally compensated. It can well suppress common mode interference and power supply voltage noise caused by power frequency, static electricity and electromagnetic coupling. Its amplification circuit principle is shown in Figure 3.
Figure 3 Schematic diagram of signal amplification circuit
Among them, pins 4 and 6 are external zero adjustment terminals, which can be connected to 10KΩ resistors and negative power supply zero adjustment. Pins 14 and 2 are external gain resistors, and pins 10 and 13 are external feedback resistors. The system has a zero error compensation function. When the single-chip microcomputer is working, the input terminal is grounded first. The non-zero data sent to the single-chip microcomputer through the measurement amplifier circuit, A/D and interface circuit is the zero error. And save the acquired zero-point error, and then take the difference between each collected data and the zero-point error as the effective sampling value to eliminate the zero-point error of the system.
3. System composition and measurement principle
The electrical principle of the system hardware is shown in Figure 4
Figure 4 System composition schematic diagram
The hardware part of the system is mainly composed of the front-end input circuit, the human-machine interface circuit, the CPU and the peripheral circuit. The required components are: the CPU uses PHILIPS 80C552, the EPROM is 2764, the sensor uses a PT temperature sensor (accuracy level is 0.5, the measurement range is -80℃--+180℃), AD521 measurement amplifier, 4 digital tubes, and a 4x4 keyboard. The
CPU uses PHLIPS80C552, and its pin arrangement has two ways, one is a 68-pin PLCC package, and the other is an 80-pin QFP80 package. The chip with the first arrangement is used here. Since the 80C552 has a 10-bit A/D converter inside, the hardware circuit omits the A/D converter, and can also obtain a higher resolution.
The system program mainly includes two parts, one is the system monitoring and management program, and the other is the sampling and measurement program.
The single-chip microcomputer is first initialized, and the initial state of the program is set to the running state. Except for entering the running state just after power-on, the program must judge the state flag bit in the future, and enter the programming or running state according to the judgment result. In the running state, the parameters cannot be edited, and the parameters can only be read out. The input signal is detected and the temperature value is displayed. Through key operation, the expansion and contraction amount of the measured axis is displayed. In the state of editing parameters, the system does not measure. When entering the programming state, it is required to enter the programming allowed password. On the premise that the password is entered correctly, the parameters can be set or modified through key operation, and the parameters are stored in the CPU.
The keyboard is a 4X4 row and column matrix, which can be configured with 16 keys. The 4-digit LED display is used to display the temperature value, and the decimal point is placed before the last digit. In order to save the hardware resources and time resources of the single-chip microcomputer I/O port and simplify the circuit, the LED display adopts a dynamic display mode. The segment selection line occupies an 8-bit I/O port, namely the P4 port, and the bit selection line occupies a 4-bit I/O port, namely the P3.4-P3.7 port. Since the segment selection lines of each bit are connected in parallel, the output of the segment selection code is the same for each bit. If each LED is to display the display character corresponding to the current bit, a scanning display method must be used, that is, at a certain moment, only the bit selection line of a certain bit is in the selected state, and the bit selection lines of other bits are in the closed state. At the same time, the segment selection line outputs the font code of the corresponding bit to display the character. That is, at a certain moment, only the selected bit of the 4-bit LED displays the character, and the other 3 bits are off.
IV. Conclusion
The system design adopts a more advanced design scheme, which improves the degree of digitization, can replace thermocouples for temperature detection, and ensures the reliability and stability of system detection. The use of other types of sensors can realize temperature measurement of different parts, which has good prospects.
Previous article：Multi-chip synchronous reset circuit based on 80C552 single-chip microcomputer
Next article：Application of 51 single chip microcomputer in thyristor trigger circuit
Planning Algorithms (Stever M. LaValle)
Latest Microcontroller Articles
- Download from the Internet--ARM Getting Started NotesA brief introduction: From today on, the ARM notebook of the rookie is open, and it can be regarded as a place to store these notes. Why publish it? Maybe you are interested in it. In fact, the reason for these notes is ...
- Learn ARM development(22)Turning off and on interrupts Interrupts are an efficient dialogue mechanism, but sometimes you don't want to interrupt the program while it is running. For example, when you are printing something, the program suddenly interrupts and another ...
- Learn ARM development(21)First, declare the task pointer, because it will be used later. Task pointer volatile TASK_TCB* volatile g_pCurrentTask = NULL;volatile TASK_TCB* vol ...
- Learn ARM development(20)With the previous Tick interrupt, the basic task switching conditions are ready. However, this "easterly" is also difficult to understand. Only through continuous practice can we understand it. ...
- Learn ARM development(19)After many days of hard work, I finally got the interrupt working. But in order to allow RTOS to use timer interrupts, what kind of interrupts can be implemented in S3C44B0? There are two methods in S3C44B0. ...
- Learn ARM development(14)
- Learn ARM development(15)
- Learn ARM development(16)
- Learn ARM development(17)
He Limin Column
Microcontroller and Embedded Systems Bible
Professor at Beihang University, dedicated to promoting microcontrollers and embedded systems for over 20 years.
MoreSelected Circuit Diagrams
MorePopular Articles
- Innolux's intelligent steer-by-wire solution makes cars smarter and safer
- 8051 MCU - Parity Check
- How to efficiently balance the sensitivity of tactile sensing interfaces
- What should I do if the servo motor shakes? What causes the servo motor to shake quickly?
- 【Brushless Motor】Analysis of three-phase BLDC motor and sharing of two popular development boards
- Midea Industrial Technology's subsidiaries Clou Electronics and Hekang New Energy jointly appeared at the Munich Battery Energy Storage Exhibition and Solar Energy Exhibition
- Guoxin Sichen | Application of ferroelectric memory PB85RS2MC in power battery management, with a capacity of 2M
- Analysis of common faults of frequency converter
- In a head-on competition with Qualcomm, what kind of cockpit products has Intel come up with?
- Dalian Rongke's all-vanadium liquid flow battery energy storage equipment industrialization project has entered the sprint stage before production
MoreDaily News
- Allegro MicroSystems Introduces Advanced Magnetic and Inductive Position Sensing Solutions at Electronica 2024
- Car key in the left hand, liveness detection radar in the right hand, UWB is imperative for cars!
- After a decade of rapid development, domestic CIS has entered the market
- Aegis Dagger Battery + Thor EM-i Super Hybrid, Geely New Energy has thrown out two "king bombs"
- A brief discussion on functional safety - fault, error, and failure
- In the smart car 2.0 cycle, these core industry chains are facing major opportunities!
- The United States and Japan are developing new batteries. CATL faces challenges? How should China's new energy battery industry respond?
- Murata launches high-precision 6-axis inertial sensor for automobiles
- Ford patents pre-charge alarm to help save costs and respond to emergencies
- New real-time microcontroller system from Texas Instruments enables smarter processing in automotive and industrial applications
Guess you like
- FPGA Design and Implementation of HDLC Control Protocol.pdf
- 【Silicon Labs Development Kit Review 03】+IO/Uart Usage
- Even if we give the complete set of drawings, Chinese people still cannot build high-end lithography machines?
- System Verilog 1800-2012 Syntax Manual
- aos multithreading and mutex lock
- Now many circuits do not have watchdogs, but some watchdog circuits are necessary. I would like to ask in which applications,...
- Brief discussion: Electromagnetic compatibility (EMC) radio frequency electromagnetic field radiation immunity test plan
- How to improve the frequency accuracy of the resonant circuit?
- [FS-IR02 + D1CS-D54] - 3: Electrical performance index detection (D1CS-D54)
- RF application scenarios——Q value
京公网安备 11010802033920号