Design And Research Of Adjustable Closed-chain Multi-legged Robot

Compared with the traditional wheeled and tracked movement methods,robots using leg-type movement systems have more outstanding maneuverability and terrain adaptability,and thus have become the focus of research in the field of mobile robots.Among them,the closed-chain multi-legged robot has high operating efficiency,simple control flow and outstanding load capacity due to its crank drive form and closed-chain structure form.However,a single foot trajectory limits its practical application,so designing a closed-chain multi-legged robot with outstanding terrain adaptability is of great significance for expanding the practical performance of this type of robot.In this paper,the concept of adjustable mechanism is used to innovate the traditional single-degree-of-freedom closed-chain leg mechanism.Based on the Watt-? mechanism,Chebyshev-pantograph mechanism and Klann mechanism,four adjustable closed-chain single-leg configurations are proposed.It mainly designs and analyzes the improved Klann mechanism,clarifies the configuration design ideas and analysis methods.Based on this configuration,a new eight-legged robot with two power drives and four adjustment drives is constructed.The improved Klann mechanism is based on the Klann six-bar mechanism,adding a degree of freedom to rotate the hinge of its frame,and realizing the adjustment of the hinge position.Using this method to obtain the continuous change of its foot trajectory,so that the height of the leg lift can be increased in the longitudinal direction to enhance the ability to cross obstacles,and the stride step can be changed in the lateral direction to achieve the planning of approaching the target point,and can also adjust the contact angle to reduces the impact of the foot of the climbing transition.This type of leg mechanism is driven by a motor while walking,which can maintain its single-degree-of-freedom characteristic,and has performance advantages in terms of small number of drives,high structural rigidity,and large load capacity.The basic rod group method was used to construct a kinematic analysis model,and the parameters were optimized with the goal of maximizing the height of the leg lift to determine the structural size,and the static analysis was carried out.Carry out the overall design of the whole machine,rationally lay out the leg mechanism and drive and transmission system,and combine the structure of the whole machine to carry out the foot trajectory analysis and stability analysis.For the purpose of improving the terrain adaptability,the steering strategy,target point approach strategy,climbing strategy and vertical wall obstacle-crossing strategy were formulated,and corresponding dynamic simulation analysis and technical verification were carried out.Finally,a prototype was developed to perform leg structure design and strength check,drive and transmission system design,control system design,complete prototype processing and assembly,and conduct adaptability tests for typical ground environments to verify the theoretical analysis of this paper correctness and feasibility of design.