Measuring the traction limits and suspension forces of a formula SAE racecar
Intercollegiate competitions have established themselves as authentic engineering experiences as both extracurricular learning opportunities and hands-on supplements to traditional course instruction. The following paper describes the integration of a Formula SAE (FSAE) team project into a junior-level mechanical engineering experimentation course; it represents one of nine projects in this course. The first half of the course is divided into modules that, for all students, progressively address: 1) the measurement chain and laboratory best practices using pre-existing experiments, 2) sensor design, selection, and calibration, 3) statistical data analysis and uncertainty limits, and 4) technical communication skills. The second half tasks student teams to propose, design, build, and carry out an original experiment to an engineering problem they perceive can improve the undergraduate experience in the department. An FSAE racecar was instrumented in order to characterize its acceleratory performance and thereby inform a strategy for overall vehicle improvement. An on-board data acquisition system received data from accelerometers, a GPS system, and linear potentiometers on the four suspension systems. These data streams were then used to determine the total forces experienced by each tire; static calculations yielded suspension loads. Lateral and longitudinal accelerations over the course of a single race track were then plotted and reduced to find the traction limits of the vehicle. In addition, a novel statistical method using traction data to compare individual drivers and overall vehicle performance was applied to two different drivers on the same track. With this metric, areas for driver improvement could be identified and potentially be used to guide an event-specific driver selection process or personalize driver training. Student learning objectives linked to ABET outcomes are described in the context of how they are assessed in this course. Results from student self-efficacy surveys and student achievement on assignments are presented and discussed as they apply to ABET outcomes b, g, i, and k.
