Simulation Study On Adaptive Control For Manipulator Of Wheel Loaders

Loader industry in China started lately. At present, the majority of domestic production of loader is still in the second-generation. The control of the loader is not good enough. For example, the method which flexible shaft control multi-way valve need a lot of power(generally about 90N). This approach is inefficient and slow. In recent years, the method which the pilot controls the hydraulic valve manually was used in a small number which reduced power greatly. The disadvantage is that such control needs a lot of pipeline which connects the multi-way hydraulic control valve and manual pilot valve.At present, many countries in the world have achieved remotely control and entered a practical stage. And the domestic product of the loader still have a wide gap between the level of foreign. Electro-hydraulic proportional control can be applied to the control devices of the manipulation which improve the intelligence and distance control to adapt to the requirements of the special working conditions.Because the operating targets of Loader is complex and changeable which make the operating conditions poor, mechanical engineering technology is very much affected if the experience and feel of human and technology determine the Mechanical manipulation.It can not make the human get rid of the heavy labor. There are four methods of excavation materials for a wheel loader in a digging process ,which are a shovel digging method, sub-shovel excavation method, mining method and the shovel digging method. In these methods, shovels digging method suffered the least resistance.In order to achieve the automatic control of loader,increase the control precision and make loader get a larger bucket load rate with power consumption as small as possible in the shortest possible time, the detailed elaborations as following:1. This paper gets a trajectory plan of bucket tip by given a better trajectory which is got by experience and the literature and posture of manipulator. There is kinematic analysis about manipulator of wheel loaders. The driver equation of the fuel tank and the boom tank is got after the coordinates from the Cartesian coordinate space to joint space and the drive space conversion.2. There are parts diagram and assembly drawing with Pro/E software. Loader models are tested. Loader models are imported into ADAMS with Mechanism/Pro. We can get data about the output of power and force after prototype model of the loader is imposed by the corresponding constraints, force, driven. 3. The performance of Electro-hydraulic proportional valves, electro-hydraulic servo valve and the general valve is compared. Manual control is changed into electro-hydraulic proportional control in the workplace. Because pilot circuit is pressure control circuit, electro-hydraulic proportional pilot valve is used. The mathematical model of Hydraulic system of electro-hydraulic proportional control system which can get open-loop transfer function and closed-loop transfer function is established with the corresponding parameters of the hydraulic system.4. The loaders is controlled by graphics-based simulink model adaptive control. The results showed that the system is followed well which meets the design objectives.