1986, Electronics Developed for Lotus Active Suspension Technology
Written by Ronald W. Cox
When GM acquired Group Lotus, the engineering consulting and performance car manufacturing firm based in the United Kingdom, one of the technologies Group Lotus brought with them was Active Suspension. This technology enabled a light weight vehicle to have much improved ride and handling. One could drive a vehicle equipped with active suspension over a rail-road track crossing, and all suspended vehicle components would be isolated from the rough crossing bumps.
Delco Electronics, a subsidiary of GM Hughes Electronics, provided CPC Engineering with prototype active suspension electronic control modules during 1986. In early 1987, CPC Engineering established a program to evaluate the technology by building a fleet of 50 active suspension Corvettes with the ZR-1 32-valve engine.
Because the electronic controller for active suspension would require a Digital Signal Processor (DSP) and special input-output circuit designs, Delco Electronics Engineering in Kokomo, Indiana assigned this project to its Delco Systems Operations (DSO) Advanced Automotive design group in Goleta, California with the provision that they were to design the system controller using DE/Kokomo approved parts and have frequent peer reviews of all phases of the design. This was the beginning of first production intent program to be developed at DSO without a handoff.
Instrumentation for this program was initially proposed to be the vehicle qualified Buick Touchscreen CRT system developed for the 1986 model year Riviera and Reatta, but the vehicle engineers preferred to have the instrumentation on their new laptops. This was the way motorsports instrumentation was developed, so DSO quickly developed the required instrumentation to communicate on the vehicles data bus and the CRT idea was scrapped.
The selection of a digital signal processor was a big event for this program as it was the first to be implemented in an active suspension system and would set a standard for other similar products to follow. A Texas Instruments (TI) DSP was selected and qualified for the program.
The required 50 units were delivered to the Bowling Green, Kentucky assembly plant as required complete with software operating as specified.