The kinematic analysis of wheeled chassis of type 8K4P

Abstract

The current level of scientific and technological progress determines the widespread robots and robotic systems in all areas of human activity - from the entertainment to industry. Robotic systems are also used in construction, geological exploration, the repair utilities, etc. It should be noted that the design of such systems takes into account the increased requirements for size, terrain, autonomous functioning (mobility) and the range of tasks. Mobile robotics plays a particularly important role in the performance of specific tasks, including dangerous to life or health (liquidation of various accidents, consequences of emergencies, working in dangerous environments). Complex robotic systems are also used for planetary studies. Therefore, scientific and applied research which related to the improvement of existing robotic systems or developing new are relevant and have obvious practical importance. The mathematical model for kinematics’ investigation of eight-wheeled chassis of the class 8K4P is presented. The chassis can move along the surface of an arbitrary profile. Wheel chassis have a number of advantages over other types of chassis, such as simple mechanisms, high speed, easy to control, energy efficiency, etc. Compared to most common wheel chassis with a rocker-bogie [2] and based on rotational wheel units [4, 5] the benefits 8K4P include simplicity of design, high terrain crossing capacity in both directions of motion [1] and the possibility of overcoming various obstacles, including commensurate with dimensions of chassis. Concrete numerical results of kinematic analysis are shown for modelling of chassis’s movement on obstacles «stairway». The advantage of developed program is the ability to take into account various requirements, including restrictions on the relative angles of sections, restrictions on the maximum value of linear/angular velocity, taking into account the possibility of changing the position of the center of mass of the mechanical system, etc. The criterion which can be used to forecast occurrence of undesirable phenomenon such as breakaway of wheels from a base surface is offered also. The specified criterion defines a relative deviation of a trajectory of movement of the center of weights of mechanical system from a straight line. As the result of performed numerical experiments geometrical parameters of the chassis which satisfy minimal value of the criterion have been obtained.