Vehicle controller

1. A vehicle controller having vehicle control modes that have different output characteristics of a travel power source relative to an accelerator operation amount, wherein

the vehicle control modes include a poor road travel mode used during travel on a poor road, and a first normal travel mode and a second normal travel mode, the normal travel modes being used during travel other than on a poor road;

a rate of increase in an output of the travel power source relative to a predetermined accelerator operation amount during an initial stage of an accelerator operation is set to increase steadily wherein the rate of increase for the second normal travel mode is greater than the first normal travel mode, and the rate of increase for the first normal travel mode is greater than the poor road travel mode; and

when the poor road travel mode is selected, an automatic or manual mode transition is permitted only to the first normal travel mode,

wherein the travel power source is at least one of an internal combustion engine and an electric motor.

2. The vehicle controller according to claim 1 , wherein, when a travel speed of a vehicle reaches or exceeds a predetermined value while the poor road travel mode is selected, a mode transition to the first normal travel mode is performed automatically.

3. The vehicle controller according to claim 1 , wherein, when a predetermined poor road travel mode termination operation is input by a user while the poor road travel mode is selected, a mode transition to the first normal travel mode is performed.

4. The vehicle controller according to claim 2 , wherein, when a predetermined poor road travel mode termination operation is input by a user while the poor road travel mode is selected, a mode transition to the first normal travel mode is performed.

5. The vehicle controller according to claim 1 , further comprising a slippage detector to detect slippage of all or a part of vehicle wheels, wherein, when slippage is detected while the poor road travel mode is selected, a mode transition to the first normal travel mode is prohibited regardless of other conditions.

6. The vehicle controller according to claim 2 , further comprising a slippage detector to detect slippage of all or a part of vehicle wheels, wherein, when slippage is detected while the poor road travel mode is selected, a mode transition to the first normal travel mode is prohibited regardless of other conditions.

7. The vehicle controller according to claim 3 , further comprising a slippage detector to detect slippage of all or a part of vehicle wheels, wherein, when slippage is detected while the poor road travel mode is selected, a mode transition to the first normal travel mode is prohibited regardless of other conditions.

8. The vehicle controller according to claim 4 , further comprising a slippage detector to detect slippage of all or a part of vehicle wheels, wherein, when slippage is detected while the poor road travel mode is selected, a mode transition to the first normal travel mode is prohibited regardless of other conditions.

9. The vehicle controller according to claim 1 , wherein transitioning between the poor travel mode, the first normal travel mode and the second normal travel mode alters one or more vehicle conditions, and

wherein the vehicle conditions are at least one of a travel power source torque, gear shift control, all wheel drive, fuel injector timing, fuel injector amounts, antilock brake control, hill decent control, limited slip differential, environmental recognition, and idling stop control.