Road Simulation Techniques for Reproducing Vehicle Behavior at Motocross Running on a Track 2018-32-0051
A Road Simulator was developed to aim reproducing vehicle behavior of actual running on motocross (MX) track in a laboratory.
Vehicle behavior while running MX track influence from various inertial forces, such as Jump landing, acceleration at full throttle, reduced speed at full braking and so on, and also load input from a rider to handlebars and footpegs must be considered, these inertial force and load should be apply on vehicle at laboratory test.
To reproduce various inertial forces such as falling inertia at jump landing, longitudinal inertia while acceleration or deceleration, and rider body action on vehicle, Active restraint systems must be added rather than traditional method of load simulator that controls wheel axles vertical and longitudinal directions with actuator. Number of hydraulic actuator was increased therefore all actuators must be controlled to eliminate interaction effect of other actuator load and action. Furthermore, introducing actuator control technology that separated Frequency Response Function (FRF) by each running event, eventually the reproduction of MX running on laboratory test was successful.
As the result, 5% or less of RMS error value was accomplished by wheel axis load, acceleration and suspension displacement at the reproduction of MX running. Herewith, accumulated fatigue damage degree of each part of frame was also reproduced at high accuracy. From the above, we achieved reproduced MX running behavior on indoor laboratory test, namely we are able to produce stable durability test without getting influence of curse condition variation such as raining, difference by riders variations, etc. moreover the test was able to run consecutive day and night and the test period was reduced. In addition, various mechanisms occurring on vehicle was able to be understood in details during the approach to reproduce vehicle behavior and load in laboratory test.
Ryota Shimizu, Hisayuki Sugita
Suzuki Motor Corp.
SAE/JSAE Small Engine Technology Conference