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.
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.
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.
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.
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.