Automated Guided Vehicles (AGVs) are one of the key equipment in modern industrial automated logistics systems. Under the unified call of the ground control system, AGVs can realize automatic handling of goods and unmanned delivery [1]. The working characteristics of AGVs require that the AGV control system should have functions such as multi-axis motor control, real-time acquisition and processing of multi-sensor data, and data exchange with the host computer. At present, due to the low cost, high integration and ease of use of single-chip microcomputers, they are widely used in motion control, but it is difficult to control multi-axis equipment; PLCs are reliable and have a large number of I/O points, but it is difficult to control two motors for interpolation motion, and the cost of controlling multi-axis equipment is high. DSP motion control cards can perform 2-axis and multi-axis control, and the price is not high, but they must be used in conjunction with industrial control computers. The functions are not perfect, and a lot of software development work is still needed. This paper proposes an AGV chassis control system with PMAC2 PC-104 motion controller as the controller. Using PMAC as the controller makes multi-axis control simpler, and the control system is more open and has strong real-time performance. 1 AGV system hardware composition PMAC (Programmable Multi-Axis Controller) is a programmable multi-axis motion controller launched by Delta Tau Digital Systems in the United States. It uses Motorola's DSP56300 processor as the CPU and can realize the simultaneous movement of up to 8 coordinate systems. It can be operated individually through the program stored inside it [2]. Using PMAC as the AGV controller, the physical structure can be greatly simplified, and the system design and debugging process becomes simpler. The AGV adopts a 4-wheel-dual-wheel drive, with the left and right coaxial wheels driven independently. The AGV driving state is adjusted through the differential speed of the two wheels. It is appropriate to use the PMAC motion controller as the core processor of the system. In order to realize the PMAC multi-axis control function, it is necessary to expand the corresponding I/O interface board on the PMAC board. At the same time, a complete open AGV control system is formed by using servo motors, servo drive units, encoders and corresponding sensors, as shown in Figure 1. Among them, PMAC mainly realizes the control of AGV drive motors, control panel switches and alarm devices. 2 AGV Control System Servo Loop Setting To ensure the accuracy and stability of AGV operation, the motor control adopts a speed and position dual feedback system, as shown in Figure 2. The variable lx03 points to the register address $720 as the address of the position encoder [3], and closes the position loop in each servo cycle. The data of the motor encoder is processed and stored in the address specified by lx03, and the position loop is closed. The variable lx04 points to the register address $721 as the address of the speed encoder, and closes the speed loop in each servo cycle. The data of the gyroscope is processed and stored in the address specified by lx04, and the speed loop is closed. When using the dual feedback system, the variable lx25 needs to be set to 1 to open the hardware position capture function of PMAC and improve the control accuracy. 3 Upper Computer Communication Programming The AGV control software is designed using Visual C++, and the movement route of the AGV is controlled by setting various parameters of PMAC, as shown in Figure 3. The AGV control software mainly realizes the functions of parameter setting, path compilation, and status diagnosis. Delta Tau provides PComm32 dynamic link library for PMAC as a bridge for communication between upper-level applications and PMAC. PComm32 contains more than 200 functions for communication between the host computer and PMAC [4]. The AGV control software controls PMAC by calling functions in PComm32. PComm32 includes PMAC1dll, PMAC1VXD, and PMAC1SYS. Using the dynamic link library provided by it and combined with Visual C++ programming, by calling functions such as OpenPmacDevice(), CloseP2macDevice(), PmacGetResponse(), and PmacFlush() provided by the dynamic link library, the PC sends the relevant data of each AGV action to PMAC in the form of ASCII code instructions, thereby realizing the exchange of commands and information between the control software and PMAC. The PMAC drive command program for executing clockwise circular motion is as follows: CLOSE &1#1 -> 4000X Set coordinate system #2 -> 4000Y OPEN PROG 10 CLEAR GOSUB 20000 Call the center calculation subroutine Q0 = Q3 - Q9 Calculate the angle from the center to the endpoint Q27 = ATAN2 (Q4 - Q10) WH ILE (Q28) 4 Conclusion AGV integrates optics, mechanics, electronics, and computer science, combining advanced theories and applications in the field of science and technology. Using PMAC as the controller, it can meet the requirements of high real-time performance and high precision in AGV movement. Its open structure facilitates future product line upgrades and system porting. References 1 Zhang Zhengyi 1 Overview of AGV Technology Development 1 Logistics Technology and Application, 2005(7): 67-73 2 PMAC 2 USERMANUAL 1 Delta Tau Data System, Inc., 2003 3 PMAC 2 Reference 1 Delta Tau Data System, Inc., 2003 4 PComm32 PMAC 32 B itD river 1 Delta Tau Data System, Inc., 2000