This paper designs an air-conditioning controller based on ARM7 ARM7 architecture, which has functions of real-time control, fault handling, real-time process data recording and network transmission of air-conditioning operation information. The software design realizes modular division, and focuses on the design of the core board program and data acquisition board program in the controller.
The field debugging results show that the air conditioning controller designed in this paper can realize all functions of the existing CRH380B vehicle, and realize the complete localization of the hardware and software of the air conditioning controller of this project.
Throughout the current domestic rail industry, several air conditioning manufacturers mainly use imported controllers for high-speed rail air conditioning. On the one hand, due to the high price of imported controllers, there is a certain blockade in technology, and there are some problems in site debugging and later maintenance and upgrading.
On the other hand, domestic passengers are also demanding more and more high-speed Rail ride environment. The higher, it is necessary to research and develop its own high-speed rail controller. The air conditioning controller designed in this paper is divided into two parts: hardware and software design. Hardware is divided into core control board and data information acquisition board; software mainly realizes data acquisition, processing, storage and upload. The advantage of this scheme is that it can satisfy the multi-input and output control of high-speed air conditioner. The special CPU is responsible for the external interface, and CAN communication is used between the main CPU. The communication is real-time and stable. Because of the requirement of CRH380B project, hardware design requires digital input of 100 routes, digital output of 60 routes, and analog acquisition of 40 routes, so this hardware design uses two 32-bit ARM7 processor LPC2292 as processor, in which the main CPU is mainly responsible for data processing and real-time interaction of cab network data, and guarantees process data. Memory, from the CPU mainly for input, output and analog data processing. In the design of hardware, ferroelectric memory is used to store the running state and fault record of air conditioner in real time. FM24V10 is a serial F-RAM memory. Its memory size is 131072x8bits. It uses I2C bus. It has many read-write times and low power consumption, thermostatic element as shown in Figure 1. In this design, PCF8523 is used as the real-time clock chip.
Compared with other clock chips, this clock chip can achieve more ready, timely and lower power consumption. Its interface circuit is shown in Figure 2.
The watchdog reset chip used in this design is CAT706.
The chip has precise under-voltage system monitoring function.
The reset function of the system with power-down detection is suitable for 3.0V, 3.6V and 5.0V systems. It provides basic reset and monitoring functions for the normal operation of the electronic system. In the software design scheme, the embedded operating system uc/OS-II is used as the software development platform, and uVision 4 in Keil-based Development Suite is used as the software integrated development environment. The development environment is a stable, reliable and efficient development tool, which is suitable for different levels of users and fully meets the needs of professional applications. The Application module design includes a main () function, which creates a startup task.
The startup task is created by the main program. Its function is to initialize the hardware of the system and create various application tasks. The main tasks include system status indication task, PTU communication task, network communication task, temperature acquisition task, data processing task and air conditioning mode judgment task. The core control instructions of the air-conditioning control system designed in this paper come from the air-conditioning instructions issued by the vehicle network. When the main CPU of the air-conditioning receives the control instructions, it judges whether the air-conditioning system will automatically enter the refrigeration or heating conditions, and uploads the air-conditioning operation status to the driver’s cab in real time, and saves the real-time operation information of the air-conditioning system, and automatically locat Functions such as management, so the main CPU programming is the focus of this design.
After on-site debugging, the air conditioning controller designed in this paper can meet the requirements of CRH380B project, realize the original control function, and add large capacity ferroelectric memory, can record more real-time operation status information and fault information, facilitate the follow-up air conditioning maintenance work, and realize the air conditioning control of CRH380B project.
Fully domesticated design of the device.