02-09-2017, 10:52 AM
In the spring of 1973, a project was started to develop a vehicle computer using a microprocessor. The effort was executed in the Department of Electronic Control Systems within GM engineering staff. This Department of ECS was created in 1971 by Trevor O. Jones under Edward Cole's directive to advance the use of electronics in automobiles. Prior to this effort, the control functions implemented by this computer had been performed with analog or mechanical circuits.
The project encompassed the development of algorithms using digital logic circuitry, custom designed interface circuits, microprocessor and memory circuits, and software implementation algorithms. Individual teams of engineers were formed to implement each aspect of the project and then worked together to create the microprocessor controlled vehicle. By mid-summer 1974, two Buick vehicles (designated Alpha IV vehicles) containing microprocessor controllers were functional and were being tested and evaluated.
Three vehicle speed control functions include cruise control, four-wheel anti-lock brake control and traction control (or anti-slip). These functions utilized high-resolution wheel speed counter interfaces for the 4-bit microprocessor and efficient algorithms to perform all control functions within a 15-millisecond update cycle. In addition to these vehicle speed control functions, the computer made speed warnings, speed limitation and automatic door locking functions and showed the vehicle's speed in digital and analog formats. The odometer and trip odometer characteristics were kept in non-volatile memories and were displayed in digital formats. Other display features included time of day and elapsed travel time.
The engine control features in this vehicle included the ignition and idle spark advance controls. To achieve these characteristics accurately, high-resolution counters were used as microprocessor inputs and outputs. The microprocessor algorithm was updated every 15 milliseconds and had to respond to accelerations and sudden decelerations of the engine. The engine speed was displayed in a digital tachometer format.
This system concept was presented in the Second Convergence Agreement and published as Document SAE 750432 - Application of Microprocessors to Authors Authors: T.O. Jones, T.R. Schlax, & R.L. Colling; Published in February 1975
After this project, another vehicle (designated Alpha V) was developed with a microprocessor controlled display system. It demonstrated many of the same functions in previous vehicles. Simultaneously, two custom integrated circuits were specified and designed. One device was an interface circuit for the microprocessor to communicate with the sensors of the vehicle. The other device was intended to calculate and display fuel economy; instant miles and average per gallon.
These demonstration vehicles gave a boost to Delco Electronics to begin a development effort in a custom automotive microprocessor design. The algorithms and interface circuits used in these projects provided a good knowledge base for this microprocessor specification. In the early 1980s, microprocessors were integrated into production vehicle systems.
The project encompassed the development of algorithms using digital logic circuitry, custom designed interface circuits, microprocessor and memory circuits, and software implementation algorithms. Individual teams of engineers were formed to implement each aspect of the project and then worked together to create the microprocessor controlled vehicle. By mid-summer 1974, two Buick vehicles (designated Alpha IV vehicles) containing microprocessor controllers were functional and were being tested and evaluated.
Three vehicle speed control functions include cruise control, four-wheel anti-lock brake control and traction control (or anti-slip). These functions utilized high-resolution wheel speed counter interfaces for the 4-bit microprocessor and efficient algorithms to perform all control functions within a 15-millisecond update cycle. In addition to these vehicle speed control functions, the computer made speed warnings, speed limitation and automatic door locking functions and showed the vehicle's speed in digital and analog formats. The odometer and trip odometer characteristics were kept in non-volatile memories and were displayed in digital formats. Other display features included time of day and elapsed travel time.
The engine control features in this vehicle included the ignition and idle spark advance controls. To achieve these characteristics accurately, high-resolution counters were used as microprocessor inputs and outputs. The microprocessor algorithm was updated every 15 milliseconds and had to respond to accelerations and sudden decelerations of the engine. The engine speed was displayed in a digital tachometer format.
This system concept was presented in the Second Convergence Agreement and published as Document SAE 750432 - Application of Microprocessors to Authors Authors: T.O. Jones, T.R. Schlax, & R.L. Colling; Published in February 1975
After this project, another vehicle (designated Alpha V) was developed with a microprocessor controlled display system. It demonstrated many of the same functions in previous vehicles. Simultaneously, two custom integrated circuits were specified and designed. One device was an interface circuit for the microprocessor to communicate with the sensors of the vehicle. The other device was intended to calculate and display fuel economy; instant miles and average per gallon.
These demonstration vehicles gave a boost to Delco Electronics to begin a development effort in a custom automotive microprocessor design. The algorithms and interface circuits used in these projects provided a good knowledge base for this microprocessor specification. In the early 1980s, microprocessors were integrated into production vehicle systems.