Pam Bionic Suspension Mechanism Characteristics

Since crawler construction machinery generally travel and work on badground, vibration and impact on their undercarriages are very serious. If driverswork under such vibration long time, the diseases such as distorted backboneand stomach will be easily triggered. Then driver' healthiness will seriously behurt and work efficiency will be greatly reduced. The bionic suspension systemhas a directly affection to comfort and stability of operation. At present, thesuspension of construction vehicles are commonly equipped with passivereduction vibration system which is composed by the elastic element and buffer.Due to the passive vibration reduction system cannot be varied with the proteanof excitation from road, so the active vibration reduction is advised in order toreduce the faultiness of passive vibration reduction system. The active vibrationreduction system can self-adjust and produces the control force that suspensionneeded. Therefore it can restrain the vibration of suspension, and in a make itselfin a good situation at the same time, in order to improve the drive comfort andstability of vehicle.Because of the rise trend of bionics in the1960s, it provided human withnew ideas of development of science and technology. With good buffer systemanimals are good at running and jumping in nature. The studies showed thatthe key of the buffer lies in its bones and skeletal muscle tissue, which canadjust to the outside world and its frequency. Base on good aspects of themuscles, the bionic muscles material pneumatic artificial muscles were invented.Pneumatic Artificial Muscle (PAM) is a new type of bionic pneumatic actuators,and it was a single output force agencies. Comparing with other active actuators,the PAM has the advantages of larger output power/weight, simply structureand good dynamic characteristics and so on. In this paper, the PAM is used asinitiative vibration reduction structure of the suspension on crawler. Bionicsuspension structure was built and its vibration attenuation property wasanalysed. As the PAM has serious nonlinear characteristics, the raditionalcontrol method is very difficult to satisfy the control demand, RBF neural network PID and Fuzzy PID are used as two intelligent control strategy in thispaper. PID control has the features of simple algorithm, robustness, and highreliability and quality control systems. In industrial control process, the qualityof PID Kp, Ki, Kdparameters account for great influence of the PID controller byperformance.The modern industrial control process is very complex, withnonlinearity, and traditional PID controller parameter setting method of controleffect is not good enough.RBF neural network is one kind of three layers of feedforward neural network method which has the strong local approximation ability,can approximate any nonlinear function with arbitrary precision.This paper,let PID control parameters self-setting online by using RBF neural network, andconstructs a PID controller structure with parameter self-setting, stablecapability.Fuzzy control has the characters that not sensitive to systemparameters changes, need not rely only on the accurate mathematical model,etc.Fuzzy PID control is one method which make PID parameters settingexperience into fuzzy control rules, according to the system input adjust PIDcontroller parameters online.This method could further improve the performanceof the PID control, which is more stable and reliable.The paper applied the2methods—RBF neural net PID and Fuzzycontrol. And it is evaluated by the maximum and minimum value of, standarddeviation of the acceleration and displacement of trolley frame. Then the mathmodel is built by4freedom of active suspension. And it is simulated in theMatlab/Simulink, which the input is the different speed and the ranks of the road.The vibration isolation performance was improved noticeably under2controlling methods.The research results can provide crawler vehicle references for thedevelopment of PAM-type damping suspension research and productdevelopment with theory basis and numerical reference.