Waukesha Engine Dresser, Inc.

Custom Designed Multi-Megawatt Engine Controller


To develop a leading edge control system for large multi-megawatt natural gas engines
To design a cost effective single solution that supported the complete family of WED engines
To control the engine with a varying quality of fuel
To design the ECU to operate reliably in a wide range of operating conditions

An unusual requirement for the packaging was that it could be used as a “step” by service engineers. This influenced the design and package dimensions leading to a robust rectangular module.


Pi Innovo established a dedicated development team consisting of systems, electronics, software and mechanical engineers.  Waukesha Engine Dresser, Inc. (WED) had a number of engines that needed to be supported, each with subtly different characteristics such as engine timing signals, number of knock sensors, number of cylinders etc. It was, therefore, critical to ensure that the requirements were captured and agreed at an early stage both to define what was to be designed in the controller but also to ensure that the controller could be configured correctly for the engine it was controlling (using the calibration tool as defined by Pi Innovo).

The controller architecture was defined from day one with fault detection and management in mind allowing for graceful degradation of performance, if required. Faults were logged and made accessible via a remote diagnostics capability with the intention that service and support activities could be undertaken more efficiently.

Control functions were based on a proprietary scheduler with an angle based module providing the foundation for control activities.  The engine timing signals needed to cater for both hall effect and variable reluctance (VR) sensor inputs.

A digital signal processor (DSP) was included in the platform as a secondary to provide knock detection and control capability through the use of a discrete Fourier transform (DFT). The knock strategy needed to cater for one or two knock sensors being installed.

Other functions implemented include:

Startup and Shutdown
Spark Timing
Misfire Detection
Lambda Control and Engine Speed Governing (e.g. Turbo Control, Throttle Control, Speed and Load Control)

ECU testing was undertaken using a Hardware-in-Loop (HiL) rig, configured to allow automated regression testing for each new release of software. To facilitate this, a plant model was developed along-side a suite of test scripts.  Engine testing and commissioning was undertaken at the client facility in Waukesha, Wisconsin.

Results and Impact

The controller was successfully commissioned and entered production in 2002.

Project Features

Hardware Design and Manufacture
Embedded Control
Model based control development
Engine control strategies design and development
Diagnostics software design and development
Robust Packaging for Hostile Environments