Abstract: A vehicular transmission system is disclosed that includes a prime mover, a transmission having at least one mode of operation where the transmission is selectively shifted into a lower gear ratio as vehicle speed decreases, a master friction clutch for drivingly connecting the prime mover to the transmission, and at least one control unit. The control unit includes logic rules that selectively prohibit the transmission from being shifted into a lower gear ratio in response to a system operating condition during the at least one mode of operation. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to prohibit the transmission from being shifted into a lower gear ratio in response to the sensed system operating condition. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: A vehicular transmission system is disclosed that includes an engine, a transmission having an input shaft, a master friction clutch for drivingly connecting the engine to the transmission, an inertia brake for selectively controlling rotation of the input shaft, and at least one control unit. The control unit includes logic rules that selectively disable operation of the inertia brake in response to a system operating condition during at least one mode of operation of the vehicular transmission system. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to log a fault or disable operation of the inertia brake in response to the system operating condition during the at least one mode of operation. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: A vehicular transmission system is disclosed that includes an engine, a transmission having an input shaft, a master friction clutch for drivingly connecting the engine to the transmission, an inertia brake for selectively controlling rotation of the input shaft, and at least one control unit. The control unit includes logic rules that selectively disable operation of the inertia brake in response to a system operating condition during at least one mode of operation of the vehicular transmission system. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to log a fault or disable operation of the inertia brake in response to the system operating condition during the at least one mode of operation. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: A vehicular transmission system is disclosed that includes a prime mover, a transmission having at least one mode of operation where the transmission is selectively shifted into a lower gear ratio as vehicle speed decreases, a master friction clutch for drivingly connecting the prime mover to the transmission, and at least one control unit. The control unit includes logic rules that selectively prohibit the transmission from being shifted into a lower gear ratio in response to a system operating condition during the at least one mode of operation. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to prohibit the transmission from being shifted into a lower gear ratio in response to the sensed system operating condition. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: 3A method/system for controlling upshifting in an automated mechanical transmission system (10) utilized on a vehicle preferably having an ECU (28) controlled engine brake (ECB) or inertia brake (26). When an upshift from a currently engaged ratio (GR) is required (ES>ESU/S), skip upshifts (GRTARGET=GR+N, N>1) and then single upshifts (GRTARGET=GR+1) are evaluated in sequence.

Abstract: A control system/method to minimize unwanted shifts in an automated mechanical transmission system (12). Initiation of shifts are prohibited unless throttle position (THL) has achieved a substantially steady-state value (|(d/dt(THL))|<REF1≈0).

Abstract: A control system/method to initiate upshifts in an automated mechanical transmission system (12). Upshifts are normally initiated on the basis of sensed throttle position (THL) or demand. In certain situation upshifts are initiated on the basis of sensed or calculated engine torque.

Abstract: A control system/method to minimize unwanted upshifts in an automated mechanical transmission system (12). Upshifts are prohibited unless throttle position (THL) has achieved a substantially steady-state value (.vertline.(d/dt(THL)).vertline.<REF-1) or a speed value (ES, IS, OS) exceeds a reference (OS<REF-2).

Abstract: A method/system for controlling upshifting in an automated mechanical transmission system (10) utilized on a vehicle preferably having an ECU (28) controlled engine brake (46). When an upshift from a currently engaged ratio (GR) is required (ES>ESU/S), skip upshifts (GRTARGET=GR+N, N>1) and then single upshifts (GRTARGET=GR+1) are evaluated in sequence.

Abstract: A method/system for controlling downshifting in an automated mechanical transmission system (10) utilized on a vehicle. When a downshift from a currently engaged ratio (GR) is required (ES<ES.sub.D/S), skip downshifts (GR.sub.TARGET =GR-N, N>1) and then single downshifts (GR.sub.TARGET =GR-1) are evaluated in sequence. If throttle demand is high (THL>REF), skip downshifts are evaluated to determine if they can be completed at no greater than a reference value (ES.sub.DES =ES.sub.DES-DEFAULT +offset), which is higher than otherwise (ES=ES.sub.DES-DEFAULT) allowed.

Abstract: A method/system for controlling downshifting in an automated mechanical transmission system (10) utilized on a vehicle. The anti-hunt logic after an upshift will sense conditions of high throttle demand (THL>85%) and low vehicle acceleration (d/dt(OS)<0) and reduce at least a portion (72) of the direction of last shift anti-hunt offset to the downshift profiles.

Abstract: A system/method of resetting the value of a control parameter (GCW.sub.CP) indicative of vehicular gross combined weight and determined as a filtered/averaged value, to a predetermined default value upon sensing vehicle operating conditions deemed indicative of a change in vehicle loading. A vehicle automated mechanical transmission system is controlled as a function of the value of the control parameter. The default value is relatively high compared to the expected range of actual vehicle gross combined weight. Large skip upshifts, greater than 50% ratio step, are prohibited after a reset until the control parameter value is verified.

Abstract: A method/system for controlling upshifting in an automated mechanical transmission system (10) utilized on a vehicle. When an upshift from a currently engaged ratio (GR) is required (ES>ESU/S), skip upshifts (GRTARGET=GR+N, N>1) and then single upshifts (GRTARGET=GR+1) are evaluated in sequence. If throttle demand is high (THL>REF), to encourage performance-oriented selection of ratios, skip upshifts are evaluated to determine if they can be completed at a higher engine speed (ESMIN=ESDEFAULT+offset) than is otherwise required.

Abstract: A method/system for controlling downshifting in an automated mechanical transmission system (10) utilized on a vehicle. When a downshift from a currently engaged ratio (GR) is required (ES<ES.sub.D/S), skip downshifts (GR.sub.TARGET =GR-N, N>1) and then single downshifts (GR.sub.TARGET =GR-1) are evaluated in sequence.

Abstract: A control method/program for rapidly confirming engagement of a target gear ratio (GR.sub.T) in an automated mechanical transmission system (92) on the basis of input signals (ES, or IS, OS) indicative of transmission input shaft (18) and output shaft (58) rotational speeds.

Abstract: An improved vehicular automated splitter-type mechanical transmission system. The splitter section is retained engaged in its currently engaged splitter ratio at power-down until vehicle speed falls below a reference (OS<REF?) or the main section (12) is shifted into neutral (GR=N?).

Abstract: An automated mechanical transmission system (92) including anti-hunt logic (FIG. 7) and logic allowing the operator to reduce or cancel the anti-hunt logic offsets by post-shift throttle pedal (THL) manipulation.

Abstract: A control method/system for controlling the operation of an electric motor (32, 42) actuated shifting mechanism (28) is provided, which includes a procedure for periodically relieving trapped frictional forces in the shifting mechanism and associated linkages (30, 38, 40). At initiation of a shifting operation (60), or periodically (66) during a shifting operation, the level of energization of the electric motor is reduced from the full target energization level thereof (68) to a minimal level (70) for a relatively short period of time (72) and then returned to the target energization level thereof. Preferably, the level of energization is returned in a 2-step process comprising stepping the level of energization to an intermediate level (76) and then ramping the level of energization from the intermediate value to the level of full target energization thereof in a ramped fashion.

Abstract: A degraded mode of operation (FIG. 7) for a partially automated mechanical transmission system (92) having a splitter-type mechanical transmission (10) with a splitter section (14) automatically shifted in only certain ratios (ninth/tenth). Upon sensing certain system faults when in this automatic splitter shifting mode, the splitter section is retained, as is, until main section neutral can be confirmed, at which time the splitter section is returned to manual control for all transmission ratios.

Abstract: A control for confirming disengagement of a disengaging gear ratio (GR). Signals indicative of input shaft speed (ES or IS) are compared to signals indicative of output shaft rotational speed (OS) to determine if the quotient of input shaft rotational speed to output shaft rotational speed (IS/OS) remains outside an increasing-sized window (GR.+-.error, GR.+-.2*error, GR.+-.3*error).