Snowmobile Traction Control

Our goal is to implement a launch control (LC)/ traction control (TC) system on the 2016 Idaho Clean Snowmobile Team competition platform, modulated via an Electronic Throttle Control System (ETC). The components will be seated in a mechanical housing that can be implemented on a variety of platforms.

=Problem Statement=
 * To improve performance of previous year’s electronic throttle control (ETC) system
 * To implement an electronic launch control (ELC) system
 * To implement a traction control system (TCS)
 * Operate under CSC team time constraints

Background
Our main goal is to improve on the previous design with the addition of an electronic traction/launch control system.

Specifications

 * Traction control system allows the sled to travel a distance in less time than the stock platform.
 * Budget is $500 for Development and $200 for final system.
 * Use of a TI Tiva C microcontroller for processing system.
 * Reduce response time of Electronic Throttle Control system to half of the previous year's design. (< 150ms)
 * Operate under CSC team time constraints.

=Design=

Electrical System
The electrical system for the sled has three main components:
 * Power Supply
 * Processing/sensors
 * Packaging/PCB

The first proposed design for the power supply included using parallel linear regulators to supply a fixed voltage while supplying the desired current. The concern with the parallel linear regulators is that they may not balance the current properly and fail. The next alternative was an off the shelf component that can supply the required current all in one package.

ETC
An electronic throttle control system (ETC) on the competition platform developed by Idaho CSC was used as the basis for our design work. An ETC system is used on the competition platform to gain a greater level of control over input to the engine and to implement other control systems.

Launch Control
The purpose of the launch control is to increase the average acceleration of the competition platform over a low traction surface from a stop. This is achieved by limiting the slip of the track which gives better grip and therefore better acceleration. The image below shows the sensor used to measure acceleration on the sled.

Implementation
The final product for the electronics on the sled are all packaged on one PCB board. This gives the electronics a more professional fit and finish than using a bread board. The PCB was designed in KiCad software. To keep the cost down, the PCB has to use only two copper layers and must be under 10cm X 10cm. The research for the trace sizes and via sizes was done using SaturnPCB software.

=Team Information=

=Document Archive=

Previous Work
The snowmobile has an ETC system built by a previous design team. The system worked at the last competition, but it has room for improvement. Our design process started with some conceptualization of control methods and learning about the embedded controller currently being used in their ETC system. We then characterized the current ETC system. Our next design phase will include selection of a mechanical actuator and controller, along with other data collection devices/methods. This will allow us to complete the ETC portion of the design and move on to the TCS system.

Current Work
The focus of work in this next iteration of the project has been on improving the response time of the system. Our main goal was to reduce response time of the ETC by 50%. After selecting a new servo, refinement of coding, and redesign of the power electronics, we were able to realize a 60% reduction in throttle response time.