Establishment of Ride Comfort Characteristics of Tractor-Semitrailer Using MATLAB and Simulink

Tractor semitrailers are widely used in the transportation industry for moving heavy-duty goods from one place to another. They operate well over an eight hour range per day, so analysing ride comfort characteristics is paramount for minimizing fatigue and stress for the driver during uptime of the vehicle. ISO 2631-1 serves as a guiding manual for the measurement and defines acceptable criteria for ride comfort characteristics of the vehicle. Tractor- semitrailers pose a major challenge due to mating of the load body on the tractor frame via the fifth wheel coupling mechanism. This independency causes the load body to act as a source of vibration and transmits the force onto the driver seat via the chassis. The location of the fifth wheel coupling is critical for ride comfort characteristics of the vehicle. Furthermore, accurate establishment of ride comfort parameters in the virtual environment saves cost and time developing prototypes and iterating on the physical vehicle. This project thus focuses on the establishing ride comfort parameters on the seat level of a 4x2 heavy tractor- semitrailer. Thus, a detailed 7-degree-of-freedom mathematical model is developed to analyze the characteristics of the vibrations in a virtual environment. The mathematical model is developed using MATLAB^® and Simulink^® R2019b. Consequently experimentation is carried out on a physical vehicle to obtain acceleration- time domain data by mounting accelerometers on various locations. The vehicle is run on A and B class road profiles to account for random vibrations. The same road vibrations are used as an input to the mathematical model. Similarly, a simulation is done on MATLAB and Simulink and a correlation is established between simulated and actual data using time domain and frequency domain analysis. Furthermore, the data is fitted on the eight-hour curve as per ISO 2631-1. Thus a versatile, parameterized mathematical model for ride comfort analysis of a tractor- semitrailer is developed.