Research On Off-road Performance Of Wheeled Vehicle With Oscillating Body Based On Interval Analysis

Not artificial paved roads is complex environments, the terrain is unknown ornot fully knowable, such as a planet's surface, the disaster scene.Therefore, mobilemachinery must have a good off-road performance in complex environments. Thisarticle is supported by the National High-Technology Research and DevelopmentProgram ("863" Program) of China. Project name is for complex unstructured terrainwheeled robot with two degrees of freedom articulated body. In this paper, relativetwo degrees of freedom wheeled vehicle (2DOF) is presented. The2DOF has theability to adapt to the terrain of good, and have a strong anti-overturning capacity.Wheeled vehicles because of its simple structure, easy to move to achievehigh-speed stability at the same time, and he moved agency has the highest energyutilization, wheeled travel system are a wide range of applications in the field of mo-bile machinery. But the wheeled vehicles worst of its ability to obstacle, usually byincreasing the number of tires to improve this shortcoming, but it brought the wholehuge oversized. The front body and rear body of2DOF are connected together bycombination of hinge. The2DOF have ability to articulated steering and each bodyaround the longitudinal axis of2DOF swing. This will not only reduce the turningradius, more importantly, can greatly improve the ability to adapt to the terrain, aswell as enhance their own anti-overturning ability. The work mining device is in-stalled in the front body and can quickly replace.The2DOF in motion, due to passive adaptation to the terrain, thereby, vehicleattitude with the terrain undulating change. In this paper, the state of motion of the2DOF is analyzed based on climb over obstacle by single wheel. Swing angle of eachbody and pitch angle of2DOF are calculated. The general dynamic equations toclimb over obstacle by single front wheel are derived based on the vehicle structuralcharacteristic.Too much traction make the vehicle produced a large inertia force, which maycause the vehicle to capsize in rough terrain, and at the same time, too much traction can also lead to energy waste. Based on these two reasons, it should be solved to en-sure that the vehicle smoothly obstacle required traction. According to the dynamicequation construction, can be seen in the process required for vehicle traction is dif-ferent in different locations. Meet the adhesion conditions, seek out the conditionslocation of required for2DOF drive torque is maximum, the location of the limit po-sition of obstacle, the drive torque provided as this condition required minimum drivetorque. Simulation, and obtained the vehicle center of gravity location of the mini-mum drive torque.Discussed separately static and dynamic stability of the2DOF based on the ve-hicle obstacle motion analysis, and gives the vehicle overturning determines. The ho-rizontal static and dynamic stability of each body are analyzed.Above, state of motion of the2DOF and off-road performance are analyzedbased on simplified model and determine the parameters. This analysis, though sim-ple, but cannot be a more realistic response2DOF obstacle performance. This is verydangerous, particularly in terms of the stability of motion. Because of any one ofthese uncertainties possible vehicle the more impaired the performance impact is verysmall, but they combine to bring the error cannot be ignored. To make the theoreticalanalysis of practical significance, and explain what uncertainty factors of the aboveconditions, some of obstacle ability of the vehicle affect the large amount of uncer-tainty as interval variables; use the interval method to analyze off-road performanceof2DOF. Interval analysis does not need to know the probability distribution of theuncertain parameters. Interval range of swing angle of each body and pitch angle of2DOF and acceleration of body and2DOF drive torque of obstacle are calculated.Further, the scope of the interval of2DOF dynamic and static stability angle are cal-culated. The upper limit of2DOF drive torque of obstacle is the theoretical value2DOF drive torque of obstacle. Range limit of2DOF dynamic and static stability an-gle is2DOF dynamic and static stability angle.Experimental verification of the2DOF goes straight and unilateral wheels ob-stacle, the pitch angle and the swing angle and acceleration are derived. Experimentalresults show that interval analysis results are closer to this situation. Experiments incomplex terrain obstacle, you can see the2DOF have strong off-road performance.