Project
OBJECTIVE: To study the model Baja-all-terrain-vehicle-atv-model to perform system-level simulation of ATV and to prepare a technical report explaining the model properties and comment on the results.
SOFTWARE : Matlab, Simulink.
VOCABULARY and technical terms used :
- All-Terrain Vehicle :
a vehicle with treads, wheels, or both, designed to traverse varied, uneven terrain as well as roads
Abbreviation: ATV
Vehicle body:
CVT:
Continuously Variable Transmission drive (CVT):
It is better to have more gears in a transmission, since it can optimize engine speed in a variety of driving conditions. That means low gears can provide better acceleration while higher gears can maximize fuel economy. CVTs differ from traditional automatic transmissions in that they don't have gears that provide "steps" between low- and high-speed operations. Instead, the majority of them work via a pair of variable-diameter, cone-shaped pulleys connected by a steel or composite belt. The halves of each pulley are aligned with the pointed ends of the cones touching. These form a V-shaped groove in which the connecting belt rides. One side of the pulley is fixed, and the other side is movable, actuated by a hydraulic cylinder. The cylinder can increase or decrease the amount of space between the two sides of the pulley. This allows the belt to ride lower or higher along the walls of the pulley, depending on driving conditions, thereby changing the "gear" ratio.
CVT shaft output graph:
VARIABLE TRANSMISSION RATIO:
Represents a variable ratio gearbox such as implemented by mechanical belt CVT, electric, or hydraulic transmissions. The physical signal input r defines the ratio of input to output angular shaft velocities.
Connections B (base) and F (follower) are mechanical rotational conserving ports. Specify the relation between base and follower rotation directions with the Output shaft rotates parameter.
ENGINE:
Represents a system-level model of spark-ignition and diesel engines suitable for use at initial stages of modelling when only the basic parameters are available. Optional idle speed and red line controllers are included. The throttle input signal T lies between zero and one and specifies the torque demanded from the engine as a fraction of the maximum possible torque.
Connections F and B are mechanical rotational conserving ports associated with the engine crankshaft and engine block, respectively. Connections P and FC are physical signal output ports through which engine power and fuel consumption rate are reported.
Signal builder:
The Signal Builder block allows you to create interchangeable groups of piecewise linear signal sources and use them in a model. You can quickly switch the signal groups into and out of a model to facilitate testing. In the Signal Builder window, create signals and define the output waveforms. To open the window, double-click the block
1. Study the baja ATV model without dashboard.
Initial model of Baja ATV model :
2. Study the baja ATV model with dashboard.
3. Study the baja ATV model using lookup table without dashboard.
vehicle speed:
CVT shaft speed:
4. Study the baja ATV model using lookup table with dashboard.
CVT shaft speed:
output:
Dynamic behaviour of Continously variable Transmission:
summery of model:
the Baja ATV model provides a useful tool for studying the dynamic behavior of an ATV and evaluating its performance under different scenarios. A technical report on this model can provide valuable insights for ATV designers, engineers, and researchers. According to the model description, the Baja All-Terrain Vehicle (ATV) model is a dynamic model that simulates the behavior of an ATV under various driving conditions. The model takes into account several important parameters. In terms of the parameters, the throttle and brake inputs are crucial for controlling the speed and stopping of the ATV. The throttle input controls the engine's power output and thus the vehicle's speed, while the brake input controls the frictional force between the wheels and the ground, leading to a decrease in the vehicle's speed. The engine rpm is also an important parameter to consider as it affects the engine's power output and the vehicle's speed. The model likely allows for varying the engine rpm to see how the vehicle's performance changes with different engine speeds.
____________________________________________________________________________________________________
References
https://www.mathworks.com/academia/student-competitions/baja-saeindia
https://www.mathworks.com/matlabcentral/fileexchange/70576-baja-all-terrain-vehicle-atv-model