Research Of Based On SMT Components Automatic Pickup Device Control Strategy

SMT is a high-precision equipment,which solder the various SMT packaged electronic welding on the PCB pads exactly.The entire device has two main aspects:First, machine vision systems using the camera to look for welding points, and then locate the position of the electronic components on the PCB, and finally by the head of the camera correct the placement of electronic components; Second, the motion control system used to control the movement of the Z-axis,X-axis and Y-axis of the head of SMT. This paper studies control system of the head of SMT.In other words using PMLSM drive attached to the titles in the Z-axis direction. This relates to control problems of PMLSM. PMLSM have high speed, simple mechanical structure and high of location on performance, so that it can solve the traditional mechanical structure speed slower,low accuracy inconvenience and maintenance problems which exist in national SMT. Contents of this paper to address these issues of placement machine has important practical significance.In order to meet the needs of the actual project. First, SMT and control systems do a brief introduction. Then it analyzes the mathematical model of PMLSM, space coordinate conversion, control method, and a detailed description of the SVPWM principles and implementation in voltage space. The combination of PMLSM used in the subject, select rotor field oriented with 0 (FOC) vector control method. Through the automatic control theory and modern control theory study, we describes the composition of various parts of the AC servo system in detail. The automatied system regulator constructors in engineering applications to bulid the entire system of the current loop, velocity loop and position loop, and then do a simulation system design and test, and analyze the stability.In order to overcome the defects in the traditional PID control of AC servo control system,system use the sliding mode control. The advantage of this type of control strategy is that the time all has the certain whether the system from the initial position to the sliding surface or on the sliding surface to reach the equilibrium point of the system by.And the system is stable and non singularity conditions, When removing the effect of control signal in high frequency oscillation. So it makes the system control accuracy and response speed boost.The hardware part and software part in the structure of AC servo control system is the focus of the work.Use the DSP28335 high speed digital signal processor as the algorithm processing unit and the model for the DRV8312 chip as the control of motor drive chip, and And use the sampling resistance and operational amplifier current to collect the current,then through the AD back to the DSP chip,finaly the current closed-loop control comes true. In order to complete the PMLSM speed loop and position loop control, use the linear Holzer sensor as the position feedback device, Through actual debugging SMT motion control.,it is demonstrate that the design of the control of AC servo hardware system and software system by us can achieve the basic requirements. And it creates conditions for the control strategy in the future more advanced is verified on the machine.