Vehicle control system

1. A vehicle control system comprising:

at least one sensor;

an electronic control unit configured to perform various calculations and computations according to programs using data received from the at least one sensor and pre-stored data, the electronic control unit having a control portion configured to determine a single parameter based on a running condition of a vehicle, and determine control amounts for a plurality of actuators provided in the vehicle based on the parameter, wherein

a relation of the control amount for each of the plurality of actuators to the parameter is predetermined; and

the control portion is configured to, when the parameter is determined, determine the control amounts for the respective actuators based on the parameter, and integrally control the actuators based on the determined control amounts, wherein

the parameter includes a parameter determined based on a synthetic acceleration obtained at each moment by synthesizing an acceleration in a longitudinal direction of the vehicle and an acceleration in a lateral direction of the vehicle, and

the parameter rises immediately in a response to an increase in the synthetic acceleration, and lowers after a difference between the parameter and the synthetic acceleration is greater than a predetermined threshold and for at least a preset amount of time.

2. The vehicle control system according to claim 1 , wherein

the parameter includes a parameter determined based on a measured acceleration detected by a sensor provided in the vehicle, or an estimated acceleration calculated from an operation amount of an operating mechanism that causes an acceleration in the vehicle.

3. The vehicle control system according to claim 1 , wherein

the plurality of actuators include at least any two of an output control actuator that changes an output from a drive power source of the vehicle, a shift actuator that changes a speed ratio of a transmission provided in the vehicle, an actuator of a steering mechanism provided in the vehicle, a suspension actuator of a suspension mechanism provided in the vehicle, and an effect producing actuator provided in the vehicle.

4. The vehicle control system according to claim 1 , wherein

the plurality of actuators include an output control actuator that changes an output from a drive power source of the vehicle, a shift actuator that changes a speed ratio of a transmission provided in the vehicle, an actuator of a steering mechanism provided in the vehicle, and a suspension actuator of a suspension mechanism provided in the vehicle.

5. The vehicle control system according to claim 1 , wherein

an operation characteristic of each of the plurality of actuators is predetermined, the operation characteristic being a relation of an operating amount to a command signal; and

the control amount includes a control amount that changes the operation characteristic.

6. The vehicle control system according to claim 1 , wherein

the control amount for each of the plurality of actuators changes at least one of a timing at which the actuator is operated, and an operating amount of the actuator.

7. The vehicle control system according to claim 1 , further comprising

an adjustment mechanism that is manually operated to change the control amounts determined based on the single parameter.

8. The vehicle control system according to claim 1 , further comprising

a switching portion that switches a running mode of the vehicle among an automatic mode, an economy mode, a sport mode, a snow mode, and a normal mode, wherein

the control portion is configured to determine the single parameter, determine the control amounts for the respective actuators based on the parameter, and control the actuators based on the determined control amounts, when the automatic mode is selected using the switching portion.

9. The vehicle control system according to claim 5 , wherein

the control portion determines whether the running condition of the vehicle is in one of an acceleration region and a deceleration region set in a tire friction circle;

if the control portion determines that the running condition of the vehicle is in one of the acceleration region and the deceleration region, the control portion determines whether a time derivative of an acceleration or an amount of change in the acceleration per unit time is equal to or less than a predetermined determination reference value; and

if the control portion determines that the time derivative of the acceleration or the amount of change in the acceleration per unit time is equal to or less than the predetermined determination reference value, the control portion changes the operation characteristic of each of the plurality of actuators using the control amount.