Powertrain Control Of Wheel Loader With Hydro-mechanical Transmission Based On Driving Intention And Condition Recognition

The hydraulic mechanical transmission has the characteristics of variable change in transmission ratio,large transmission power and high efficiency,which is the development trend of construction machinery transmission such as wheel loaders.Based on the research of wheel loader’s driving intention and conditions recognition,this paper carried out the research of hydro-mechanical transmission control strategy based on driving intention and condition recognition.The main work content is as follows:(1)Carry out research on the recognition of loader driving intention.Through the analysis of the driving intention of the loader,the driving intention of the loader is divided into acceleration intention,braking intention and fast lifting intention,taking the accelerator pedal signal and brake pedal signal as recognition parameters,a loader driving intention recognition system based on fuzzy reasoning is designed.The driving intention recognition model of the loader was built,and simulation analysis was carried out to realize the accurate recognition of driving intention.(2)Carry out research on the identification of typical conditions of loaders.The cluster analysis method based on K-means is used to classify the conditions of the loader,and five typical conditions with characteristic parameter information are obtained.Using the method of fuzzy pattern recognition,the constructed five typical working conditions of loaders were identified,a simulation model for identifying typical conditions of loaders was built,and simulation analysis was carried out to verify the accuracy of the identification methods of typical conditions of loader.(3)A fuzzy control strategy of loader hydro-mechanical transmission system based on driving intention and typical conditions is proposed.With driving intention and typical conditions as input parameters and control factor S of control strategy biased to economy or power as output,the control strategy model and loader vehicle model are established,and the simulation analysis is carried out.The simulation results show that the gearbox control strategy designed in this paper has a relatively higher maximum speed and better dynamics compared to the control strategy based on the best economic curve as the engine target speed curve.On the premise of ensuring the power performance,compared with the control strategy which takes the best dynamic curve as the target speed curve of engine,the fuel consumption per unit time is reduced by 14.49%.(4)An xPC-based controller hardware-in-the-loop simulation platform is built to conduct hardware-in-the-loop simulation experiments on the control strategy of hydromechanical transmission based on driving intentions and typical conditions.Compared with the computer simulation results,the average error of the control strategy control factor is0.3%,the average error of the engine fuel efficiency per unit time is 0.43%,and the average error of the loader speed is 3.23%.The control strategy of the gearbox controller of the hydraulic mechanical loader and the hardware-in-the-loop real-time simulation test platform basically meet the functional requirements.