Self-AWPs, or self-propelled aerial work platforms, are unique vehicles designed to move people to work locations by extending structures.  The Self-AWP can reach a very modest top speed of 6.8 km/h. It takes a long time to drive the Self-AWP to the destination when the working location is farther away, and driving on the road is prohibited. Therefore, a truck or trailer is required, but their breadth is constrained. 
Self-AWPs, or self-propelled aerial work platforms, are unique vehicles designed to move people to work locations by extending structures.  The Self-AWP can reach a very modest top speed of 6.8 km/h. It takes a long time to drive the Self-AWP to the destination when the working location is farther away, and driving on the road is prohibited. Therefore, a truck or trailer is required, but their breadth is constrained. 

First, the application of the extended axle steering mechanism in Self-AWP is explained.The steering error model of the extensible axle steering system is then created. At the same time, the idea of double-error is established.

Secondly, according to the double-error of steering mechanism, the model of  the double-error is established as a multi-objective problem. In order to  eliminate the sideslip of the tire, the mean relative error square is consider  as the objective function, and the base angle and the waist length are consider  as the design variables. Then the boundary constraint condition and the  performance constraint condition are established. With the MATLAB genetic  algorithm toolbox, the multi-objective problem is solved using multi-objective  genetic algorithm. The result of the multi-objective optimize problem is a set  of Pareto. Based on pseudo-weighted vector method, the interested set is  selected form the set of Pareto. And with a certain type of self-propelled  aerial work platform as an example, it is improved by the multi-objective  optimize technology and proves the feasibility and rationality of the  optimization method.

The best layout guidelines for a steering mechanism with an extended axle are then investigated utilizing the solution obtained from the optimization evaluation. Furthermore, the two most crucial steering mechanism characteristics are the base angle and the waist length. After evaluation, the optimization data is handled using the least squares method in data processing technology.

Then the experience formulas having the two of treads are got, which will  guide the future design the same type of steering mechanism with extendable axle  in Runshare Self-AWP.