Synthesis And Application Study Of Plane Six-Bar Linkage

Steering mechanism is very important in the driving facilities of vehicles. One important aspect of designing steering mechanism of vehicles is that the front wheels of steering mechanism must satisfy the steering condition. The most common steering mechanism for vehicles is plane four-bar linkage, which has a simple structure and has been studied in details. However, six-bar linkage has the advantages of more members, more variables and higher steering precision and plane six-bar linkage can be used to replace four-bar one as steering mechanism for vehicles to satisfy the steering condition better. So, some research on plane steering six-bar linkage has been done in this project as follows: based on the condition equation of correct steering and the equations of two closed loop of steering mechanism, a set of three equations in three variables can be obtained after a variable is expurgated with the elimination method. Then with the computer graphic method, the real solution of this equation group can be generated.The objective function based on Fourier descriptors is presented that compares purely the shape of two plane, closed curves without being affected by the location, size, or orientation differences between the curves. Then, the software for path generation of six-bar linkage is developed to compare purely the shape of two random curves, and a plane six-bar mechanism is optimally synthesized based on that software.The computer graphic method is put forward to solve a set of three polynomial equations of high order in three variables. With the mathematic computation software, Matlab, the program is designed in which the value of two variables in certain range is taken with certain pace of increment, and the two variables in the range is corresponding to one point value; the value of the two variables are taken in circle and introduced into the known three equations, then the corresponding value of the third variable can be calculated; protract the point value and its corresponding value of the third variable, and the two-dimensional graphic of the three equations can be generated. Translate the coordinates of the intersections of the three curves into the value of corresponding variables, which is the solution of the three equations. By taking these intersections as initial value, all exact real solutions of the equation group within a certain range of value are generated with the unrestraint optimization method.