Driving dynamics (3cr)

Objective

Upon completion of the course, students will:
- be competent in determining the formation of driving resistance under various circumstances.
- understand the factors affecting fuel consumption.
- be able to determine the factors corresponding to the performance of a car
- be able to seek information on the subject

Content

Theory:
- Power generation / formation of engine power
- Driving resistances (road load forces)
- Driving condition diagram / tractive effort diagram
- Acceleration
- Significance of final drive ratios
- Fuel consumption
- Elasticity (engine flexibility / torque elasticity)
- Acceleration and gradeability limits

Automotive labs:
- Determining the tire–road contact patch
- Experimental determination of the center of gravity
- Simulation of driving resistances using a dynamometer

Qualifications

Mechanics, Statics

Assessment criteria, satisfactory (1)

Recognizes different driving resistances (rolling, aerodynamic, gradient, and acceleration resistance), but the definitions contain inaccuracies. Understands engine and drivetrain losses at a general level but cannot assess their effect on total resistance. Recognizes the significance of final drive ratios but cannot independently evaluate their impact on acceleration or top speed. Identifies the basic factors affecting fuel economy (mass, resistances, speed, engine operating range), but does not yet grasp their relative importance. The calculation and interpretation of laboratory exercise results remain at a basic level.

Assessment criteria, good (3)

Determines driving resistances correctly in various situations and can calculate the required power and torque for different driving conditions. Takes engine and drivetrain losses into account and evaluates their contribution to total losses. Interprets the tractive effort diagram reliably and uses it in performance calculations. Can assess the effect of final drive ratios on a vehicle’s acceleration, top speed, and fuel economy. Evaluates factors affecting fuel consumption in practical examples and identifies the driving conditions that have the greatest impact on fuel usage.

Assessment criteria, excellent (5)

Is able to determine all driving resistances and analyze their relative significance in different driving situations. Creates and interprets tractive effort diagrams and uses them in demanding performance prediction tasks. Analyzes the effects of final drive ratios on overall drivability, fuel economy, and dynamic performance, providing technically justified reasoning. Calculates and interprets the limits of acceleration and gradeability even in complex situations and can assess the limitations of the models used. Is capable of analyzing fuel economy in various driving conditions and evaluating both fuel consumption and energy losses as a whole. In laboratory exercises, perform measurements systematically and with high accuracy, taking error sources and their effects into account. Analyzes results critically and links them to the theoretical models of vehicle dynamics.

Materials

Material distributed during the course and available in the course’s Moodle.

- Tuononen & Koisaari; Driving Dynamics
- Gillespie; Fundamentals of Vehicle Dynamics