CASE STUDY

Custom Electronics Solution for Sensorless BLDC Motor Control

Challenge

The BLDC control challenge was complex due to the requirement to eliminate speed sensors and resolvers for lower cost. Having previously developed sensorless BLDC control from first principles on a daughterboard in an M250 OpenECU controller as a proof of concept, the Pi Innovo engineering team understood the technical difficulties that would be faced.

In addition to the requirement to eliminate sensors, the Pi Innovo team was required to design the electronics to survive being packaged in the same housing as the motor itself, and not to rely on a good airflow environment. This added the additional challenges of heat rejection from the electronics and EMC considerations from being in close proximity to an electric machine, making part selection and design analysis critical development tasks

Solution

In order to reduce the risk of the controller design, Pi Innovo selected a microprocessor from Texas Instruments that incorporated low-level control functionality in protected ROM that allowed for sensorless BLDC motor control. Taking this approach reduced the complexity of software that had to be written, leaving the Pi Innovo software and systems team free to focus on application development, diagnostics, and communication with the device from the vehicle or service tool.  Pi Innovo’s hardware engineering team leveraged our extensive experience in meeting harsh automotive and other custom application requirements to design the motor integrated electronics package.

Results/Impact

Pi Innovo’s solution for sensorless BLDC control met the cost and performance targets, and was ready for launch into volume manufacture 10 months after project kicked off.

Project Features

Custom Electronics Design
Software Development
LIN Communications
Controls Development
Diagnostics

Duration

10 months