Design Of Visual Servo Control System For Intelligent Forklift

With the rapid development of China’s economy,the traditional manual transportation links of enterprise have begun to transform from mechanization to automation and intelligence,the demand of factory logistics and warehouse logistics for automatic transportation equipment with high degree of flexibility is growing rapidly.As the main force of logistics transportation equipment,forklift is gradually approaching to advanced technologies such as intelligent identification,autonomous navigation and positioning,intelligent forklift is studied and designed under this background.The main research contents are as follows:The mechanical structure of traditional forklift is analyzed and studied.The fivewheel structure of a single steering wheel is reformed with the chassis.The steering mechanism is designed through independent innovation in the later period.The combination of the steering motor-the driving wheel-the belt-the driving wheel-the steering bearing is adopted.The resistance of the vechile body under the condition of motion is analyzed,and obtains the resistance and the output power of the vechile body under the condition of different weight of goods.The overall hardware control system of intelligent forklift is designed.The main control equipment selects the INVIC controller developed by Codesys,and the co-control equipment selects Beckhoff EtherCAT terminal module,which together constitutes the control unit of intelligent forklift.The circuit design of hardware includes driving circuit,goods transplanting circuit and multi-sensor fusion circuit.The signal collecting terminal adopts the terminal module of Beckhoff EL1809,EL2809 and EL4102.In order to realize the flexible control of the intelligent forklift,the relevant intelligent control algorithm is designed.Based on the analysis of the working mechanism of the magnetic navigation sensor,the tracing algorithm is designed to solve the problems of poor stability and large tracing error of the traditional algorithm.On the basis of the traditional Dijkstra algorithm,a "three-point straight segment" constraint condition was added to optimize the motion path with the least number of turns.In view of the traditional fuzzy obstacle avoidance algorithm,a new area influence factor is introduced on the basis of distance influence factor,which significantly improves the obstacle avoidance effect.Based on recognition technology of QR code,combined with the hybrid algorithm of Gradcut image segmentation and Canny edge detection,the edge detection of the target image is realized,and then use the least square method to fit the edge contour which is regarded as the discriminant condition of vehicle posture adjustment.The test results show that the intelligent forklift can realize the basic functions of autonomous navigation,autonomous positioning,autonomous recognition,autonomous load shifting,and has the characteristics of strong mobility,high stability and good safety.