This article introduces the structure of a material handling system using pneumatic components, the pneumatic system itself, and its PLC control system. The material handling method offers multiple functions, including gripping and suction. The pneumatic system's electromagnetic directional valves utilize a manifold assembly, reducing space requirements. The PLC control system offers various operating modes, including single-step and automatic. Due to its advantages such as convenient air source use, environmental friendliness, flexible and rapid operation, reliable safety, ease of operation and maintenance, and suitability for harsh environments, pneumatic transmission is widely used in toxic or high-temperature environments such as stamping, injection molding, and die casting; machine tool loading and unloading; conveying and automatic assembly of small parts in the instrumentation and light industry sectors; food packaging and conveying; electronic product conveying and automatic assembly; and automated ammunition production. Therefore, pneumatic transmission is an easily promoted and widely adopted technology for industrial automation. The application of pneumatic systems has attracted widespread attention from industries worldwide, and the pneumatic industry has become one of the fastest-growing sectors in industrialized countries. Currently, most pneumatic systems utilize programmable logic controllers (PLCs) as their control devices. A programmable logic controller (PLC) is a new type of universal automatic control device developed based on microprocessors and integrating computer technology, automatic control technology, and communication technology. It boasts high reliability and ease of operation. In practical applications, the control system is easily implemented. Generally, the sequence of actions of the controlled equipment and process requirements form a step state table, which is then used to create a ladder diagram, and PLC instructions are programmed. I. Material Handling System Structure Design The schematic diagram of the material handling system is shown in Figure 1. This system consists of left and right moving cylinders 1, reset and retracting cylinders 2, lifting cylinders 3, grippers or vacuum suction cups 4, material blocks 5, sensors 6, cylindrical guide rails 7, brackets 8, bases 9, and microswitches 10. The grippers or vacuum suction cups 4 can clamp or suction the material blocks 5. The material gripping part adopts both clamping and suction types; different types can be selected to complete the gripping and suction of workpieces respectively, adapting to different types of material handling. The grippers use electromagnets to engage and disengage to hold the materials. The gripper or suction cup can move up and down under the action of the lifting cylinder 3; the gripper or vacuum suction cup, together with the lifting cylinder, can move left and right along the cylindrical guide rail under the action of the left and right moving cylinder 1; under the action of the reset forward and backward cylinder 2, the material block is sent back to its original position to prepare for the next work cycle, thus realizing the cycle. This system can realize the material handling in one plane. The left and right movement stroke is 300mm, and the up and down movement stroke is 80mm. Different cylinders are selected according to the stroke. Cylinders 1 and 2 have a stroke of 300mm, and cylinder 3 has a stroke of 80mm. The cylinders are flange-mounted. In order to prevent the workpiece from deviating, guide cylindrical guide rails 7 are installed on both sides of the movement path of the left and right moving cylinder 1, and the cylindrical guide rails are fixed to the bracket 8 with screws; the bracket is fixed to the base 9 with bolts. [align=center] Figure 1 Schematic diagram of material handling system[/align] Two magnetic switches 6 are installed on the cylinder body of the left and right moving cylinder 1 for left and right limit position detection; a micro switch 10 is installed on the base for material block lower limit position detection. The control panel is mounted on the electrical control box, separate from the main body of the experimental setup. The PLC programmable controller, solenoid valves, vacuum generator, etc., are all housed within the electrical control box. II. Pneumatic System Design The pneumatic schematic diagram is shown in Figure 2. [align=center]Figure 2 Pneumatic Schematic Diagram[/align] The gas from the air source is processed by a two-piece assembly before entering the manifold. Through corresponding electromagnetic directional valves, it enters the pneumatic actuators, driving the left and right movement of cylinder 1, the pushing action of cylinder 2, the rising and falling movement of cylinder 3, and the gripping and releasing action of suction cup 4. All three cylinders in the entire pneumatic system use outlet throttling speed regulation; the solenoid valves consist of three 2-position 5-way valves and one 2-position 2-way valve. A manifold-type electromagnetic directional valve is selected, with all solenoid directional valves housed together on the manifold to reduce space occupation. III. Program Flowchart and Software Design Function Implementation. The material handling system has left and right movement, up and down movement, and functions for clamping and releasing materials, as well as pushing and retracting. Under PLC control, it can achieve various working modes such as single-step and automatic. In addition, after the material is moved by the gripper, it must be returned to its original position to meet the needs of continuous operation for the next handling. The system can perform the following working modes: Single-step: It can realize eight inching operations: "rise", "fall", "move left", "move right", "clamp", "release", "push forward", and "push backward"; Continuous: After pressing the "start" button, the gripper continuously performs each step of material handling from the original position. Based on the above tasks, the main program flowchart is designed first, as shown in Figure 3. [align=center] Figure 3 Main Program Flowchart[/align] The actions implemented by the material handling system are: fall → grip → rise → move right → fall again → release → rise again → move left → push forward → push backward. In this system, we only implement one material cycle action, so after the robot returns to the original position, the material needs to be pushed back to its original position. Under PLC control, the system can achieve both single-action and continuous operation modes. After the system is powered on, the rotary button selects between single-action and continuous operation. If single-action is selected, the single-action program is executed; otherwise, the continuous operation program is executed. Single-action mode: Each action of the gripper is controlled individually using buttons. Continuous operation: Pressing the start button starts the gripper from the origin and automatically cycles through the process until the stop button is pressed. After completing the last cycle, the gripper returns to the origin and automatically stops. See Figure 4. [align=center] Figure 4 Flowchart of Continuous Operation Sequence[/align] IV. Conclusion The PLC-controlled material handling system can achieve automatic cyclic material handling. This system can use grippers to hold materials and vacuum suction cups to pick up materials, offering multiple functions. The pneumatic system's electromagnetic reversing valve is housed in a manifold, reducing space requirements. Under PLC control, both single-action and continuous operation modes can be achieved to complete material handling. References [1] SMC (China) Co., Ltd. Modern Practical Pneumatic Technology [M]. Beijing: Machinery Industry Press, 1998. [2] Li Guoping et al. Development of PLC-based Pneumatic Manipulator Experimental Device [J]. Hydraulics and Pneumatics, 2003(1):28-29. [3] Deng Xingzhong. Electromechanical Transmission Control [M]. Huazhong University of Science and Technology Press, 2001.