An actual gear ratio change amount (Gr) is calculated by subtracting a pre-shift gear ratio (Gb) from an actual gear ratio (Gr). A gear ratio (G) is calculated by multiplying the actual gear ratio change amount (Gr) by a predetermined coefficient (C) and adding the product value to the pre-shift gear ratio (Gb). When the shift is an upshift, the gear ratio (G) is compared with aa target gear shift ratio (Ga), and the greater value is set as a virtual gear ratio (Gv). When the shift is a downshift, then the gear ratio (G) is compared with the target gear ratio (Ga) and the smaller value is set as the virtual gear ratio (Gv). A virtual input shaft rotational speed (Nv) is calculated by first dividing the actual gear ratio (Gr) by the virtual gear ratio (Gv) to obtain a quotient and by dividing the actual input shift rotational speed (Nr) by that quotient. A slip amount (S) is calculated by subtracting the actual input shaft rotational speed (Nr) of the automatic transmission (3) from the engine rotational speed (Ne). Finally, the engine rotational speed for display (Nd) is calculated by adding the slip amount (S) to the virtual input shaft rotational speed (Nv).

An actual gear ratio change amount (Gr) is calculated by subtracting a pre-shift gear ratio (Gb) from an actual gear ratio (Gr). A gear ratio (G) is calculated by multiplying the actual gear ratio change amount (Gr) by a predetermined coefficient (C) and adding the product value to the pre-shift gear ratio (Gb). When the shift is an upshift, the gear ratio (G) is compared with aa target gear shift ratio (Ga), and the greater value is set as a virtual gear ratio (Gv). When the shift is a downshift, then the gear ratio (G) is compared with the target gear ratio (Ga) and the smaller value is set as the virtual gear ratio (Gv). A virtual input shaft rotational speed (Nv) is calculated by first dividing the actual gear ratio (Gr) by the virtual gear ratio (Gv) to obtain a quotient and by dividing the actual input shift rotational speed (Nr) by that quotient. A slip amount (S) is calculated by subtracting the actual input shaft rotational speed (Nr) of the automatic transmission (3) from the engine rotational speed (Ne). Finally, the engine rotational speed for display (Nd) is calculated by adding the slip amount (S) to the virtual input shaft rotational speed (Nv).

A hydraulic control system of an automatic transmission for a vehicle provided with an idle stop and go (ISG) system includes a mechanical hydraulic pump driven by a torque of an engine, the mechanical hydraulic pump pumping a fluid stored in an oil pan, a regulator valve, a manual valve, a linear solenoid valve for controlling the hydraulic pressure supplied from the manual valve through the second hydraulic line and for supplying the controlled hydraulic pressure to a third hydraulic line, a switch valve, and an electric hydraulic pump driven by electric energy for pumping the fluid stored in the oil pan through a fifth hydraulic line and for feeding the pumped fluid to a sixth hydraulic line connected to the fourth hydraulic line.

A hydraulic control system of an automatic transmission for a vehicle provided with an idle stop and go (ISG) system includes a mechanical hydraulic pump driven by a torque of an engine, the mechanical hydraulic pump pumping a fluid stored in an oil pan, a regulator valve, a manual valve, a linear solenoid valve for controlling the hydraulic pressure supplied from the manual valve through the second hydraulic line and for supplying the controlled hydraulic pressure to a third hydraulic line, a switch valve, and an electric hydraulic pump driven by electric energy for pumping the fluid stored in the oil pan through a fifth hydraulic line and for feeding the pumped fluid to a sixth hydraulic line connected to the fourth hydraulic line.

A differential lock and parking structure is provided for a dual power source driving speed reducer, that includes first and second shafts, a differential lock mechanism, and a parking mechanism. The first and second shafts are connected to dual power sources, respectively; the differential lock mechanism and the parking mechanism are provided at the tail ends of the first and second shafts; and the differential lock mechanism includes a movable chainring assembly, a fixed chainring assembly, and a fixed armature assembly. The parking mechanism includes a parking gear integrated with a fixed chainring, a pawl assembly, and a parking cam assembly that drives the pawl assembly to realize the conversion between parking-in and parking-out.

A differential lock and parking structure is provided for a dual power source driving speed reducer, that includes first and second shafts, a differential lock mechanism, and a parking mechanism. The first and second shafts are connected to dual power sources, respectively; the differential lock mechanism and the parking mechanism are provided at the tail ends of the first and second shafts; and the differential lock mechanism includes a movable chainring assembly, a fixed chainring assembly, and a fixed armature assembly. The parking mechanism includes a parking gear integrated with a fixed chainring, a pawl assembly, and a parking cam assembly that drives the pawl assembly to realize the conversion between parking-in and parking-out.

A method of parameterization of traction force interrupted shifts in a transmission of a commercial vehicle having a frame, a cab supported by the frame, and a trailer coupled to the frame. The method includes a mathematical model which considers movement equations and geometrical parameters of the frame, the cab, and the trailer. Traction force patterns of traction force interrupted shifts are predetermined which depend on a traction force decrease time, a shift time, and a traction force increase time. From model and force patterns, vibration behaviors of the cab as the output parameter of the model is simulated. The parameterization of traction force interrupted shiftings takes place such that, as the shifting parameters, the traction force decrease time, the shift time, and the traction force increase time of such force patterns are determined, for which a defined evaluation criterion of the simulated vibration behavior of the cab is optimal.

A control apparatus for a vehicle includes a determination unit that determines whether or not a start condition is established, the start condition including a torque converter is in a non-lock-up state and the vehicle is starting; and a display control unit that causes a virtual number of rotations to be displayed on a tachometer instead of an actual number of rotations when it is determined by the determination unit that the start condition is established. The display control unit calculates an acting number of rotations by referring to the actual number of rotations and a number of rotations on a driving wheel side relative to the torque converter in an automatic transmission, and causes the acting number of rotations to be displayed on the tachometer as the virtual number of rotations.

Systems and methods for reducing perception of transitions from shifting a transmission from neutral to drive are described. In one example, the transmission is shifted from neutral to drive in response to brake pedal motion before the brake pedal is fully released so that timing of pressurizing clutches and engaging a forward gear is advanced to occur while the brake pedal is still applied.

First, the pressure of oil within an oil passage in a control valve device is measured. Then, an amplitude and period of pressure fluctuations are detected on the basis of an obtained measurement result, and an oil vibration state or an oil non-vibration state is diagnosed. In this case, when the amplitude is greater than a reference amplitude value and when the period is less than a reference period value, the oil vibration state is diagnosed. Further, a duration time of the oil vibration state is determined on the basis of a diagnostic result. Then, when the oil vibration state continues for a period greater than or equal to a reference time, warning information is output. In this way, warning information is output stepwise in accordance with occurrence or continuation of oil vibration.