Integrated engine and transmission control system

A control system for a vehicle having an engine connected to and adapted to drive an automatic transmission through a torque converter, the transmission including a plurality of transmission gear ratios and a means for automatically establishing a particular gear ratio in response to a transmission control signal, comprising:

• a first microprocessor-based controller adapted to sense at least one operating parameter and produce transmission control signals in response to the sensed parameter and in accordance with a predetermined shift map, the first microprocessor-based controller further being adapted to produce a CTSSPEED signal a first time period following initiation of a gear change operation and thereafter continue production of the CTSSPEED signal for a second time period, the CTSSPEED signal corresponding to a speed which is a predetermined amount above a synchronization speed of the new gear for an upshift and a predetermined amount below the synchronization speed in the new gear for a downshift, the first time period corresponding to time required for the transmission to disengage the old gear ratio and the second time period corresponding to the time required for the transmission to engage the new gear ratio;
• an engine speed sensor adapted to sense engine speed and produce an actual engine speed signal;
• means for producing an operator desired engine speed signal;
• and
• a second microprocessor-based controller adapted to receive the operator desired engine speed, actual engine speed, and the CTSSPEED signals, calculate an error signal in response to a difference between the actual and desired speed signals when the CTSSPEED signal is not received, calculate an error signal in response to a difference between the CTSSPEED signal and the actual engine speed signal when the CTSSPEED signal is received, and regulate engine speed into so as to reduce the error signal to zero.

A method of effecting shifts in a vehicle having an engine connected to and adapted to drive an automatic transmission through a torque converter, the transmission including a plurality of transmission gear ratios and a transmission actuator for automatically establishing a particular gear ratio in response to a transmission control signal, comprising the steps of:

• sensing when a gear change is required and determining a first time period, a second time period and a desired engine speed, the first time period corresponding to time required for the transmission to disengage the old gear ratio, the second time period corresponds to the time required for the transmission to engage the new gear ratio and the desired speed corresponding to a speed which is a predetermined amount above a synchronization speed of the new gear for an upshift and a predetermined amount below the synchronization speed in the new gear for a downshift;
• initiating the gear change operation;
• determining when a time equal to the first time period has elapsed since the shift was initiated and regulating engine speed into correspondence with the desired speed for a period of time equal to the second time period;
• and
• thereafter controlling engine speed in accordance with an operator desired engine speed until another shift is required.