A design scheme of elevator controller based on single chip computer is proposed. The functions of motion control, floor display and emergency call of the 8-storey manned elevator are realized. This paper introduces the design process of elevator controller system, and expounds the design principle of the system.
Hardware uses STC89C52 single-chip computer, keys, relays, buzzers, digital tubes, etc. to build a hardware circuit operating platform. On this hardware, the control program of single-chip computer is designed by using C language to realize the control of hardware.
The system has the advantages of simple control, high intelligence and good safety. It can be widely used in high-rise buildings which need elevators. With the acceleration of urbanization, the number of high-rise buildings is also increasing. In order to facilitate the travel of people in high-rise buildings, elevators are more and more widely used. In order to ensure that the elevator can work safely and smoothly, it is necessary to configure a set of elevator controller which is safe, reliable, flexible and has the function of real-time display. It can ensure the efficient operation of the elevator, at the same time, it can also guarantee the personal safety of passengers. Therefore, the research of elevator controller has important practical significance. An 8-storey elevator operation control system is designed, which uses STC89C52 as the core control.
By collecting input keys, the output LCD display, door indicator and alarm output are controlled. Specific implementation functions are as follows: 1) Simulate the design of the upper and lower operation control system of the 8-storey elevator; 2) realize the operation display and danger alarm; 3) complete the optimal route selection of the elevator by judging the input button; 4) realize the action control of the switch door, call and reset by pressing the button. Through the analysis of the functions of the system, this design acquires the floor information, rescue information and the control command information of the door by the detection of the input keys.
After the controller collects the control information, it processes it, controls the relay module, controls the movement process of the elevator, thermostatic element and displays it by the display part. The current floor information, after reaching the target floor, sends out a reminder sound, and according to the trigger state of the switch button, controls the indication of the switch door indicator light and the indication of the elevator going up and down. According to the analysis, the design consists of six parts: STC89C52 main control module, key module, power module, display module, alarm module and relay control module. The system structure is shown in Figure 1. Main control module: to achieve the acquisition of the input module, after processing, control the output module; power module: power supply for each module of the system; alarm module: after receiving the alarm command, send out alarm sound; key module: to complete the target floor input information, door information and emergency call information collection; display module: to achieve: The display of the target floor can also be instructed by switches; the relay control module: after receiving the order, control the elevator motor work, and realize the up and down control of the elevator.
The hardware of the system consists of the minimum system of single chip computer, display circuit, key circuit, alarm circuit, relay control circuit and power circuit. P0 port is connected with RK1 pull-up resistor, which drives the segment selection of LED common-yang digital tube, and the common terminal power supply of digital tube. The elevator external key circuit consists of eight keys, representing the call of eight floors. The keys are low-level and effective. Eight keys are connected to the PC port of the single chip computer.
When the keys are pressed, the corresponding pins will detect the low-level, which can be used to judge the call floor.
Elevator internal control requires 12 keys, including 1-8 floor internal keys, open keys, close keys, call keys and reset keys. In the design, P2.1-P2.3 control row scan and P2.4-P2.7 control column scan are used. The keys pressed in the ladder can be determined by row scan of matrix keys. The relay is controlled by the pin of P2.
0 of MCU. The contacts of the relay are connected to the power supply of AC contacts, and the control of the elevator motor is realized by controlling the coil of the contactor. Overview of the system process: keys are input signals, STC89C52 MCU receives signals and processes them. The target floor is displayed on the digital tube, and the command is sent to the relay circuit to control the elevator to start moving. The floor information is updated and displayed with the action of the elevator.
When arriving at the target floor, press the key to open the door, open the door indicator light, buzzer sounds, when passengers leave the elevator, press the key to close the door, the light to close the door is lit, buzzer sounds. If the call is pressed, the buzzer keeps giving an alarm until the reset button is pressed. The program idea of this design is as follows: power supply of the system, interruption of initialization operation of single-chip computer, initialization of input/output pins of single-chip computer in initialization, and initial display of digital tube as “1”, representing the elevator parked on the first floor. After the display is completed, the program enters an infinite loop, in which the following operations are performed sequentially: to determine whether a key is pressed or not, and if no key is pressed, to return to the keyboard judgement to continue execution. If the key is pressed, the key processing function is executed to determine the target floor to be reached, if the current floor is smaller than the target floor, if the current floor is larger than the target floor, the downlink processing function is executed, if the current floor is equal to the target floor, after updating the display, return to the key detection place and continue to cycle until the target floor is larger than the target floor. The system will not be powered down.
This paper mainly introduces the design scheme of the 8-storey elevator control circuit based on STC89C52 single chip computer. The schematic diagram of the hardware and the flow chart of the software are given. The operation control of the 8-storey elevator is realized by coordinating the software and hardware. On the basis of controlling elevator’s normal operation, call button and alarm circuit are added in the design, which makes the system have the function of calling for help and greatly enhances the flexibility of system application.
This design has the advantages of flexible control, strong practicability, visual display, etc. It can meet the needs of elevator control in different high-rise buildings.
Therefore, this case has good application value and market promotion prospects.