Synchronizing and gear engagement sensing logic for automated mechanical transmission system

A control system for controlling an at least partially automated transmission system including a mechanical transmission, an input shaft driven by a controllable engine and an output shaft, and having a plurality of selectively engageable and disengageable jaw clutches for selectively engaging and disengaging selected gear ratios having known numerical values, sensing means for providing signals indicative of input shaft (IS) and output shaft (OS) rotational speeds and a system controller for receiving input signals including said signals indicative of input shaft and output shaft rotational speeds and for processing same in accordance with predetermined logic rules to issue command output signals to system actuators including an engine controller for controlling rotational speed of said motor, said logic rules including rules effective:

• to engage a target gear ratio (GR.sub.T) from neutral by commanding said engine controller to cause said engine to rotate at a speed (ES) causing the input shaft speed to equal the sum of (i) the product of output shaft speed and the numerical value of the target gear ratio, plus (ii) the value of a first offset (X) where ES=IS=(OS*GR.sub.T)+X;
• and
• to determine engagement of a gear ratio when, for a first predetermined period of time, sensed input shaft speed is equal to or greater than the difference of (i) the product of output shaft speed and the numerical value of the target gear ratio, minus (ii) a second positive offset and is equal to or less than the sum of (i) the product of output shaft speed and the numerical value of the target gear ratio, plus (ii) said second positive offset (Y) where ((OS*GR.sub.T)-Y).ltoreq.IS.ltoreq.((OS*GR.sub.T)+Y),
• the absolute value of the first offset exceeding the value of the second offset .vertline.X.vertline.>Y.

A microprocessor-based system controller for controlling an at least partially automated transmission system including a mechanical transmission having an input shaft driven by a controllable engine, an output shaft, and having a plurality of selectively engageable and disengageable jaw clutches for selectively engaging and disengaging selected gear ratios having known numerical values, sensing means for providing signals indicative of input shaft (IS) and output shaft (OS) rotational speeds and an engine fuel controller for controlling rotational speed of said engine, said system controller receiving input signals including said signals indicative of input shaft and output shaft rotational speeds and processing same in accordance with predetermined logic rules to issue command output signals to system actuators including said engine fuel controller, said system controller having a memory storing logic rules effective for:

• to engage a target gear ratio (GR.sub.T) from neutral, commanding said engine controller to cause said engine to rotate at a speed (ES) causing the input shaft speed to equal the sum of (i) the product of output shaft speed and the numerical value of the target gear ratio, plus (ii) the value of a first offset (X) where ES=IS=(OS*GR.sub.T)+X;
• and
• determining engagement of a gear ratio when, for a first predetermined period of time, sensed input shaft speed is equal to or greater than the difference of (i) the product of output shaft speed and the numerical value of the target gear ratio, minus (ii) a second positive offset and is equal to or less than the sum of (i) the product of output shaft speed and the numerical value of the target gear ratio, plus (ii) said second positive offset (Y) where ((OS*GR.sub.T)-Y).ltoreq.IS.ltoreq.((OS*GR.sub.T)+Y),
• the absolute value of the first offset exceeding the value of the second offset .vertline.X.vertline.>Y.