Abstract: A new method for controlling the steering and trajectory of the electric mobile robot is proposed. In order to control the robot’s position and heading, the path error and the heading error of the robot are taken into the control closed loop. On the basis of the self-adaptive PID control method combined with preview theory and fuzzy logic, a trajectory tracking control system is designed. Finally, experiments and simulation are conducted to test the control system. Both experimental and simulation results show that the mobile robot can approach the target trajectory quickly and then move along it, which confirm the validity and the efficiency of the trajectory tracking control system.
Abstract: Tension control is a crucial technology for winding control. In the present work, a theoretical analysis and design of tension control used in the winding systems for lithium-ion battery is proposed. Through analyzing the winding process of battery batteries, a speed control curve of the winding motor is designed, with which we can achieve a constant-linear-speed operation of the pole-pieces. Based on the electronic CAM technology, using the approximation method, the constant-linear-speed control curve is obtained. Experimental work is done to study the actual evolution curve of speed for battery pole-pieces. Experimental results show that the rate of speed fluctuation between the maximum speed and the minimum speed reduces from about 10 times to 2 times. It confirms the effectiveness of the application of electronic CAM control strategy in tension control.
Abstract: In order to research the turning stability of a semi-active suspension vehicle, the suspension damping BP (Back Propagation) neutral network PID (Proportion–Integral–Differential) control technique was proposed. The ideal and actual yaw rate error is taken as the control targets to carry on the turning stability closed-loop control. The vehicle yaw rate is controlled to analyze the impacts of the suspension damping change on the wheel vertical load and roll. The MATLAB software was applied to carry out simulation according to the single lane steering and step turning working conditions. The results show that the suspension damping can be controlled to control the vehicle yaw and cornering motions in the process of the vehicle turning on the high adhesion road. When the front suspension damping is increased and the rear suspension damping is decreased synchronously, the load transfer of the left and right wheels of the front and rear axles is obviously decreased, thus being able to effectively restrain the over-steering behavior of the vehicle.
Abstract: Tolerance characteristics have an important influence on products dynamic properties. To realize dynamic properties oriented tolerance analysis and design of mechanical products, a data-driven based tolerance analysis method was proposed. Firstly, based on the cloud model theory, an assemble cloud model was established, and a new method of assembly data processing and knowledge mining was proposed. Secondly, the assembly cloud model was used to analysis the measured data from practical assembly process and search the alignment laws. Finally, using the above mentioned methods, product key parts tolerance was analyzed and adjusted, and the product quality consistency could be improved dramatically.
Abstract: During milling of thin-walled components, chatter vibrations give rise to process issues. These include dimensional inaccuracy, damaged and scrap parts, and damaged cutting tools. This, in turn, leads to loss of production time with increasing cost as a consequence. This paper identifies the force profile during a single cut milling process. It focuses on the exit and post-exit behavior of the cut and discusses the process dynamics. The force profiles of various tool-to-workpiece positions are analyzed as regards the exit and post exit phases. A standard on-the-market cutter and a specially designed zero rake cutter are used in the investigation. Finally, a time-domain simulation of the force is performed and compared to the experimental results. The study concludes that a small change in exit angle may result in a considerable improvement in cutting behavior. In addition, the tool position should be chosen so that the cutter exits in the least flexible direction possible for the workpiece.
Abstract: Wire feeder is a welding wire delivery device widely used in TIG and CO2 gas welding. Smooth wire feeding directly affects the quality of welding. A small welding wire feeder was improved. The wire feeder and the welding wire plate were centrally located in the torch. This has reduced the wire transmission resistance and increased the mobile flexibility. Practical application proved that it has the characteristics of wire feeding stable and reliable, high welding productivity and high quality and stability of weldments. It has a significant impact on improvement of the existing welding and broad application prospects in welding industrial production.
Abstract: To solve the fault detection problems of position transducers operating continuously under complex conditions of hot rolling line, and improve the reliability of the control system, a fault detection method based on Kalman filter and sequential probability ratio was presented. Through building the control model of the system, processing the output data of transducers with Kalman filter, and processing the residuals with sequential probability ratio and improved methods, the judgment criterion of transducer fault detection and the method of data reconstruction were given. The simulation results show that, the method can quickly detect position transducer faults, give the reasonable estimated state value, and improve the reliability of the system.
Abstract: In this paper, the overall structure of a high-speed camshaft grinding carriage and the key components such as electric spindle system and feed system are presented. The model analysis of the electric spindle and grinding carriage box is established to verify the feasibility of the design.
Abstract: Aiming at the characteristics of mechanical gear transmission, taking automobile main reducer as research object, this paper analyzes the gear transmission of failure mechanism and failure characteristics. According to the good time frequency character and adaptive ability of wavelet analysis, it proposes gear fault information extraction method based on wavelet packet analysis and have carried out simulation analysis. The results show that the method of wavelet packet analysis can effectively detect mutations in the signal part and noise to achieve the diagnosis of mechanical system failures.
Abstract: It put forward the design scheme of the multi-parameter data acquisition based on the existing sensors and related test equipment in laboratory. The system selected the acceleration and speed signals as the measured parameters. The PC computer was taken as the host computer and the PCI-6014 data acquisition card was used to achieve the data collection, analysis, storage and display of various parameters. At the same time the host computer sent the control signal to SCM. The SCM of AT89S52 was used as the slave computer to receive the control signal from the host computer and give an alarm signal. To achieve the real-time control for the data acquisition, the communication between the host and slave computer was achieved via the RS232 serial communication technology.