The Design of Stereoscopic Parking Garage Based on PLC Control System

In cities, traffic congestion has become a social problem that governments are concerned about. Traffic and vehicle parking management in urban areas is becoming more and more difficult, especially in high-end hotels, guesthouses, and large department stores in urban areas where vehicles are densely populated. Due to the impact of the original area, it is impossible to increase parking spaces. Parking difficulties and traffic congestion have become a big problem. According to statistics: In Beijing, more than 500,000 cars are parked on both sides of the road every day; in Shanghai, there are more than 800,000 cars that have nowhere to park every day. These problems will hinder the rapid development of the automobile industry.

Author: Anonymous

foreword

In cities, traffic congestion has become a social problem that governments are concerned about. Traffic and vehicle parking management in urban areas is becoming more and more difficult, especially in high-end hotels, guesthouses, and large department stores in urban areas where vehicles are densely populated. Due to the impact of the original area, it is impossible to increase parking spaces. Parking difficulties and traffic congestion have become a big problem. According to statistics: In Beijing, more than 500,000 cars are parked on both sides of the road every day; in Shanghai, there are more than 800,000 cars that have nowhere to park every day. These problems will hinder the rapid development of the automobile industry.

In the previous underground garages, sufficient driving passages were required, and each car would occupy an area of ​​about 40 square meters. If a double-layer three-dimensional garage is adopted, the utilization rate of the ground can be increased by nearly 90%. If the above-ground multi-storey three-dimensional garage is used, at least 40 vehicles can be stored on a land area of ​​50 square meters. This saves our limited land resources and saves the cost of civil development. Secondly, compared with the underground garage, the three-dimensional garage can more effectively ensure the safety of people and vehicles. When a person is in a garage or where a car cannot be parked, the entire electronically controlled device will not function. The three-dimensional parking equipment can park a large number of cars in a small area, eliminating the problems of ramp design of ramp-type parking garages. The research on transforming the architectural space problems in the design of parking garages into mechanical methods, and using new technologies to solve the parking problems. With computer control, the garage area is unmanned and will effectively prevent theft and damage. It is only because the mechanical parking equipment saves the area and provides flexible parking. It can be used in a large area or in a small area. It can also be combined with ground parking lots and underground parking garages. It has become a solution to urban parking difficulties. One of the most effective means is the only way for the development of the parking industry. In a sense, the three-dimensional parking garage has completely achieved the separation of people and vehicles in management.

With the development of the economy and the gradual improvement of people’s living standards, the number of cars has grown rapidly, and people’s demand for garages has become higher and higher. Since most of the cars are concentrated in large and medium cities, the substantial increase in the number of urban cars will inevitably lead to an increase in the demand for parking spaces. The annual demand for garage doors is as high as 3 million units, while the actual production is 1.5 million units. The demand for automatic doors and industrial doors is 4.6 million square meters, of which the demand for automatic doors is 2.5 million square meters.

There are many types of mechanical three-dimensional parking garages, which can be divided into lifting and traversing type, vertical circulation type, vertical lifting type, plane mobile type, roadway stacking type, horizontal circulation type and other types according to the principle and structure. Among them, the lifting and traversing three-dimensional parking garage occupies a small area, and the scale can be flexibly changed according to the site and needs. In this paper, a three-story 10-space lifting and traversing three-dimensional parking garage is taken as the research object, and a PLC-based control system is designed and implemented on S7-1200. As electrical engineering technicians, we should strive to introduce today’s high-tech achievements into their design of automatic garage doors, and design a set of low-cost, high-efficiency, high-reliability, and user-friendly automatic garage doors in order to be in a favorable position in the market competition. The automatic garage has a wide range of applications, not only for commercial garages, but also for housing supporting garages. The social and economic benefits of its popularization and application are very significant, and it is of great significance to improve the appearance of the city.

1. The structure and working principle of the three-dimensional parking garage

The three-dimensional garage control system includes a vehicle access system, a vehicle management system (vehicle identity authentication, parking charges, etc.) and a monitoring and security system. The automatic access car system is the core of the three-dimensional garage control, which is controlled by PLC. Including two processes of card number recognition and load box movement. A non-contact card reader is installed at the entrance (also the exit) of the garage. When the user enters the garage, swipe the card at the door to enter, the card reader automatically transmits the data to the PLC, and the PLC system automatically determines whether the card is valid. If it is valid, then When the door of the warehouse is opened, the system moves the load box to the handover position of the person and the vehicle to shorten the time for accessing the vehicle.

Lifting and traversing three-dimensional parking garages access vehicles by lifting or traversing the car board. It is mainly composed of six major parts: main frame, vehicle board, transmission system, control system and safety protection measures. The main frame is the support structure of the three-dimensional garage, usually steel structure. The vehicle carrier plate is used to carry the stock vehicles, and there is a traverse motor on the vehicle carrier plate, which drives the whole vehicle carrier plate to perform traverse motion. The carrier on the carrier board is connected with the frame by four steel wire ropes, which can be lifted and lowered. The transmission system of the lifting and traversing three-dimensional parking garage is divided into a lifting transmission system and a traversing transmission system, which is the core part of the whole garage system. The control system of the lifting and traversing three-dimensional parking garage can use hardware such as single-chip microcomputer and programmable logic controller (PLC) to control the state of relays and contactors to complete the lifting and traversing actions. Safety protection measures are the safety guarantee of the three-dimensional garage. Generally, there are emergency stop switches, overrun devices, vehicle length detection, car blocking devices, anti-fall devices, warning devices, etc.

2. Design of intelligent control system for three-dimensional garage

This design is based on Siemens PLC, the PLC performs arithmetic processing on the data, and then controls the operation of the field equipment to complete the automatic, efficient and accurate operation of the monitoring and control system of the urban drainage pumping station.

The control system of this design is fully automatic control. When the simulation software WINCC is started, just press the start button to start, and the PLC will control the stereoscopic garage through the corresponding program written by the Botu software.

In the control system of the lifting and traversing three-dimensional parking garage, there are a large number of switch signals such as the start-stop signal of the motor and the detection signal of the sensor. The control mode is logic control and sequence control, so PLC is selected as the main control unit to control the system. Design, the control system chooses Siemens S7-200 PLC as the main control unit. Various sensor detection signals of the lifting and traversing stereoscopic parking garage are input to the PLC controller through the digital input channel. After the PLC performs calculation, the output signal is transmitted to the stereoscopic parking garage through the output channel, and the execution of the lifting motor and the traversing motor is completed. The control action of the components, the three-dimensional garage control system flow is shown in Figure 1.


Figure 1 Flow chart of the three-dimensional garage control system

3. Control system hardware configuration

3.1 Main circuit design

The main driving motor adopts a 22KW AC two-speed motor, KM1 is connected to the rising contactor, KM2 is connected to the falling contactor, KM3 is connected to the low-speed winding, KM4 is connected to the high-speed winding, KM4 short circuit cuts high short circuit cuts off high speed starting reactance, KM31 short circuit Connect to cut off low-speed reactance. L is a smoothing reactor that limits the current. When starting (braking), in order to limit the starting (braking) current, reduce the impact of grid voltage and the acceleration during starting (braking), the stator winding is connected in series with one-stage reactance, and the step-by-step step-down start (braking).

Library layer sensing circuit. The warehouse floor induction is realized by the on/off of the main leveling travel switch in the 4 corners of each floor, and the warehouse floor signal is sensed, which is used for floor pointing, direction selection, floor selection, and hall call cancellation. The induction signal is required to be continuous, and the signal disappears only when the carrier moves to the upper or lower layer.

② Call circuit in the car or in the hall. This circuit is different from elevator control. In the three-dimensional garage car and hall call circuit, the car call button is placed on the operation box in the load box. It is not usually used. It is only used when maintenance or administrators need to enter the designated warehouse location. Easy to operate.

③ Lateral movement circuit. The lateral movement circuit refers to the control circuit that pushes (or pulls out) the truck into (or pulls out) the left and right storage positions when the load box is moved to the designated floor and is leveled. The solenoid valve lock (the upper limit switch of the load box) operates.

④The load box starts the speed change and leveling circuit. The AC two-speed motor has two sets of windings: high-speed winding and low-speed winding, the high-speed winding is 4 poles, the low-speed winding is 16 poles, and the speed ratio is 4:1.

3.2 PLC selection

The system needs 74 digital inputs and 36 digital outputs, which requires a certain margin during configuration. The basic unit cannot meet the requirements of input and output, and it is necessary to add expansion modules to integrate various factors. This design uses Siemens s7-1200 PLC, CPU 1214C, 5 digital input modules, 2 digital output modules, which can meet the needs of the design of the three-dimensional garage control system.

3.3 IO point analysis of control system

(1) Control box. The control box is the operation interface of the control system, and should be equipped with control buttons such as parking space selection, start/stop, emergency stop, reset, and automatic/jog switching.

(2) Whether the vehicle is detected or not. In order to determine whether there is a vehicle on the carrier board, a sensor for detecting the presence or absence of a vehicle should be installed on each carrier board.

(3) Accurate positioning detection. In order to ensure whether the car carrier moves to the designated position, a detection device for detecting whether the car carrier is lifted or moved horizontally should be installed in the corresponding parking space.

(4) Vehicle overlength detection. In order to prevent overlong vehicles from entering the parking space, a detection device to detect whether the vehicle is overlong is installed at the entrance of the garage.

(5) Lifting motor. Due to the large power required for the lifting and lowering of the carriage plate, an AC motor is selected. The lifting and lowering of the carrier is controlled by the forward and reverse rotation of the motor.

(6) Traverse motor. Using a small AC motor, the traverse motion of the carriage is controlled by the forward and reverse rotation of the traverse motor.

(7) Anti-fall device. When the middle or top car-carrying board is parked, in order to prevent the carrier from falling, an anti-falling device is installed on the corresponding parking space, which is in the form of a hook and is driven to open and close by an electromagnet.

(8) The indicating device of the garage. Running lights, warning lights and bells. When there is a parking space in the garage, the running light is on to remind people to pay attention; when an emergency occurs, the alarm light flashes and the alarm bell rings.

4. Software design

The main function of the PLC control system of the lifting and traversing three-dimensional parking garage is to access the car. The jog control method is to adjust the car carrier to the predetermined position through the “up”, “down”, “left” and “right” keys, which is mainly used for debugging, maintenance or emergency treatment; the automatic control method is a three-dimensional parking garage. In the normal working mode, when a certain parking space is selected to access the car, the system automatically determines the parking space movement plan and invokes the corresponding parking space movement program to automatically complete the car access operation.

The main problem of access car control is to solve the problem of parking space movement. When selecting a parking space to access the car, all the parking spaces below it need to be removed to establish a down channel. The establishment of the downlink channel must follow the principle of high efficiency, which includes two aspects: the time to establish the downlink channel is the least, that is, the distance that the parking space moves is the shortest;

When selecting the parking space on the ground floor to access the car, since the vehicle can directly enter and exit the parking space on the ground floor, the car access operation can be performed directly without considering the position of the vacant space. When the access parking space is selected as the middle layer or top floor parking space, according to the principle of high efficiency, the selected parking space is compared with the vacant spaces on the layers below it. If the vacant space of a certain floor is on the left side of the parking space, move the relevant parking space of the floor to the left; if the vacant space of a certain floor is on the right side of the parking space, move the corresponding parking space of the floor to the right, and finally form a channel under the selected parking space. It is convenient for the parking space to be lifted and lowered to complete the operation of accessing the car.

In order to ensure the reliable and efficient control of the access vehicle, a reset rule for the access vehicle is established. The rules of the parking space traverse reset: the rank reset is not performed for the traverse parking space. During the establishment of the downlink channel, the parking spaces on the layers below the top floor need to be traversed. In order to ensure the efficiency of accessing the car, it is stipulated that after the car access is completed, the traversing parking space does not need to be reset, and directly participates in the establishment process of the next downlink channel. When the system is forcibly reset, each parking space returns to its original position. Parking space lift reset rules: lift the parking space for floor reset. In order to ensure the reliability of the car access control, it is stipulated that after the car access is completed, if the system does not forcibly stop the system, the descending parking space completes the car access operation and then rises in time to restore to the floor where the parking space is located.

According to the above-mentioned reset rules for the access car, the parking space lifting actions of the storage and retrieval operations have reached a consensus, that is, regardless of the storage or retrieval operation, the parking space is first lowered from the floor to the ground floor, and after the parking and retrieval operation is completed, Timely rise to restore to the original level. Therefore, the same control program can be used to realize the access control of the same parking space, which improves the execution efficiency of the control program and saves the storage space.

5. Summary

This paper mainly designs the intelligent control system design of stereo garage based on Siemens 1200 PLC. Because the PLC program control of soft wiring is adopted, the reliability of the system is greatly improved. The three-dimensional garage automatic control system based on PLC makes the operation process simple, reliable in operation, reduces maintenance costs, and realizes the intelligentization of the control process. The system tries to make some actions run at the same time in the process of accessing the vehicle, such as lifting, lowering and moving forward and backward of the load box, which greatly saves the time for accessing the vehicle. In addition, the system can also be extended to high-rise and multi-storage locations, which is suitable for car-intensive communities or parking lots.

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