Abstract: The portable locomotive speed signal generator can simulate the running parameters of the locomotive and accurately output the speed change signal, which is convenient for the maintenance personnel to check the fault point in time and improve the maintenance efficiency. The device adopts a hand-held structure, and integrates a pulse forming module, a power amplifying module, fault diagnosis, information display, input and output and other functional modules to form a complete system capable of independently and accurately simulating the locomotive speed signal, and is convenient. Effectively and reliably detect the line condition related to the speed signal of the locomotive. This paper describes in detail the development plan, system structure and main functional characteristics of the signal generator, and introduces its field use. This article refers to the address: http:// The locomotive speed detection system is an important link between the reliable control of the locomotive and the safe operation of the locomotive, which directly affects the safety punctuality of the locomotive operation. At present, the locomotive speed signals required for the transition device, monitoring device, anti-aircraft system and vehicle bearing detection device of the main trunk locomotives in the railway are provided by the speed sensors mounted on the axles of the wheels. The photoelectric speed sensor is generally used, and the speed signal is provided to the speedometer, the train operation monitoring and recording device system, the locomotive control electronic cabinet, and the diesel engine excitation system. When the locomotive is returned to the section for repair, because the speed of the motor train or the speed of the train is not high, there is no speed signal output or the signal strength of the output speed is not enough. Therefore, the system detection that requires the speed signal becomes a difficult task in the test and maintenance of the locomotive. To this end, the design and development of the locomotive photoelectric speed sensor analog signal generator, so that the locomotive simulates the speed signal in the static non-moving situation, is of great significance to meet the needs of locomotive maintenance work. 1 overall plan 1.1 System Design Principle The analog signal sent by the equipment is compatible with the speed sensor output signals installed on the DF4D, DF8, DF11, SS7, SS8 and SS9 locomotives currently used on domestic railways. At the same time, due to the different wheel diameters of various machines, The equipment should be able to adjust the wheel diameter and output the corresponding frequency pulse. The locomotive speed signal generator should meet the following requirements: 1) The signal output is a square wave signal with a duty ratio of 50%, and the high level is 12V; 2) The output bandwidth is 2 to 9 999 Hz; 3) the maximum DC current is 10 mA; 4) the output accuracy is 1%; 5) the number is used. The LCD head display corresponds to the speed of the locomotive; 6) It is applicable to various photoelectric speed sensors of the DF-16 type. 1.2 main system block diagram The main system block diagram is shown in Figure 1. 2 system design 2.1 hardware circuit design 2.1.1 MCU to simulate the pulse signal generation circuit of the sensor Since the operating frequency of the MCU is up to 12 MHz, and the highest frequency of the locomotive speed signal is 4.23 KHz (300 km/h), the accuracy of the analog signal is set by the MCU (<0.05%), and the operation is simple and the interface is friendly. . 2.1.2 Power System The power supply system mainly supplies power to each system. In order to ensure the safety of the speed signal generator and the locomotive circuit, all power supplies adopt optocoupler isolation measures to ensure that the locomotive and the generator work independently. The device mainly needs 5 V, 3.3 V, etc. The power supply adopts a modular DC-DC switching power supply, and the DC-DC switching power supply has an extremely wide input range. 2.1.3 Human-computer interaction interface With a 3.5-inch color LCD screen, the display uses a TFT bus type with full hardware implementation. Not crash, stable and reliable. 2.1.4 Speed ​​signal output and acquisition circuit In order to ensure the safety of the speed signal generator and the locomotive circuit, the input and output of the signal adopt optocoupler isolation measures to ensure that the locomotive and the generator work independently. 2.2 Software Design ATmega16 can effectively support C language and assembly language in software. C language has become the standard language for designing embedded systems. It has the characteristics of general high-level language structured programming, good readability and convenient maintenance, and low-level language such as assembly, which is convenient for hardware access and high code efficiency. This design is implemented in C language programming and has good portability. The program flow chart is shown in Figure 5. 2.2.1 Pulse generation software design The most important data output of the speed signal generator is the speed signal. The pulse frequency of the speed signal is directly determined by the speed and the wheel diameter, and is proportional to the speed and inversely proportional to the wheel diameter. The device sets the wheel diameter of the actual locomotive through software, sets the simulation speed, and sends out the corresponding speed signal through software calculation. The following describes the speed pulse signal generation part in the program: The program idea is: firstly from the set speed and wheel diameter, the wheel speed is calculated by calculation, the cycle of the required signal is calculated from the wheel speed, and the cycle is analyzed, and the cycle is corrected by specific parameters to obtain the required frequency. Finally, the timer is configured to output a corresponding pulse signal at the I/O port. 3 Conclusion The portable locomotive signal generator based on ATmega16 single-chip microcomputer has the advantages of low power consumption, simple structure and high cost performance, and reduces the peripheral interface device and improves the system operation reliability. In the actual application, the speed signal of the four-way locomotive can be tested at the same time. It has the advantages of simple, reliable, convenient maintenance, easy operation, safe operation and flexibility. The test result is intuitive and can directly display the power supply error and disconnection of the speed detection part of the locomotive. Error and speed detection accuracy, etc. CBD Atomizer,CBD HHC oil Cartridges,Full spectrum Thc oil HHC vapor,Live Rosin HHC Oil vape,Delta 8 oil Atomizer Shenzhen Yingyuan Technology Co.,ltd , https://www.yingyuanvape.com
