Cosper Engineering

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MFTS: MultiFunction Turn Signal Controller

Overview

Motorcycle turn signal controller with auto-reset and lean assist lighting. Designed with an MCU, embedded control firmware, and an onboard 6-axis IMU. The turn signals are activated by the rider via left/right push button controls before the turn. The controller detects when the turn is complete using the IMU sensor data, and automatically resets the turn signal.

Auto Turn-Signal Reset Function

An electronic motorcycle component that controls its turn signal lamps. Auto turn-signal reset has been a common feature on 4-wheel automobiles for decades, implemented with simple steering wheel rotation detection. Motorcycles, on the other hand, do not lend themselves to this simple approach. The steering mechanism for 2-wheel vehicles (motorcycles) is more complicated. Thus the use of an IMU to detect the vehicle turn.

IMU orientation

Engineering Challenge: Turn Complete Detection

Distinguishing a completed turn, where the turn signal should reset, from in-lane maneuvering presents challenging design trade-offs. Our solution uses a combination of configuration with an adaptive algorithm.

turn dwg

Lean Assist Lighting Function

Extra left and right forward lighting that turns on to assist the standard forward-looking headlights.

Engineering Challenge: Lean Angle Detection

Only the turn-side assist lamp is to activate when the motorcycle is leaning to make a turn, requiring 'lean angle' detection. A challenging task given motorcycle kinematics, dynamics, and noise. The controller calculates the lean angle using the IMU sensor data.

Centrifugal Forces Az Ay Diagram

Engineering Challenge: Road Testing

Validating the IMU-based turn detection and lean angle algorithms on real roads under varying conditions — speed, load, surface, and rider style. The motion dynamics sensing (IMU) and data procession used to achieve these features are not easily duplicated in a lab setting, requiring extensive on-vehicle on-road testing. Tools had to be developed; A custom CAN bus recording device was used to log rider input, IMU dynamic motion data and controller output. A custom software tool was developed to streamline analysis of the large logged data files captured.

Road Testing MFTS CAN Logger CAN Logger Connection
Logged Turn Graph

Engineering Challenge: ISO 16750 Compliance

Demonstrating compliance with the automotive standard for electrical loads related to the power supply.

Engineering Challenge: Production Auto-Test

Designing an automated test fixture and sequence to verify each production unit's IMU calibration, firmware integrity, and output stage health in a fraction of the manual test time.

Engineering Challenge: In-Field / On-Vehicle Firmware Updates

Enabling firmware updates on installed vehicles.