Automatic gear shifting control device of vehicle

An automatic gear shifting control device of a vehicle, comprising:

• a control part that is configured to execute an automatic gear shifting operation of a transmission in response to at least vehicle speed;
• a first sensor that detects a rotational speed of a front wheel, which constitutes a driven wheel;
• a second sensor that detects a rotational speed of a rear wheel, which constitutes a drive wheel;
• a vehicle speed detector that detects the speed of the vehicle;
• and
• a rotational-speed-difference detector that is configured to detect a difference in rotational speed between the front wheel and the rear wheel based on information from the first sensor and information from the second sensor,
• wherein the control part is configured to execute an automatic gear shifting control in response to the vehicle speed, the vehicle speed based on the rotational speed of the front wheel when the front wheel has a greater rotational speed than the rear wheel and based on the rotational speed of the rear wheel when the rear wheel has a greater rotational speed than the front wheel or based on the speed of the vehicle detected by the vehicle speed detector,
• wherein when the rotational speed of the rear wheel decreases to create a difference in rotational speed between the front and rear wheels, the automatic gear shifting control is executed toward a lower gear side from a change gear ratio on the rotational speed of the front wheel,
• wherein when the front wheel is locked or the rotational speed of the front wheel is lower than the rear wheel, the gear shifting control is executed toward the lower gear side from the change gear ratio on the rotational speed of the rear wheel, and
• wherein a gear shift toward a shift up side is executed until a difference in rotational speed between the front wheel and the rear wheel is no longer detected.

An automatic gear shifting control device of a vehicle, comprising:

• a first sensor that detects a rotational speed of a front wheel which constitutes a driven wheel;
• a second sensor that detects a rotational speed of a rear wheel which constitutes a drive wheel;
• and
• a rotational-speed-difference detector that is configured to detect a difference in rotational speed between the front wheel and the rear wheel based on information from the first sensor and information from the second sensor,
• a control part configured to determine a larger rotational speed out of the rotational speed of the front wheel and the rotational speed of the rear wheel when the difference in rotational speed between the front wheel and the rear wheel is detected, calculating a vehicle speed from the front wheel when the front wheel has a greater rotational speed than the rear wheel and calculating the vehicle speed from the rear wheel when the rear wheel has a greater rotational speed than the front wheel and executing an automatic gear shifting operation of a transmission based on the calculated vehicle speed,
• wherein when the rotational speed of the rear wheel decreases to create a difference in rotational speed between the front and rear wheels, the automatic gear shifting control is executed toward a lower gear side from a change gear ratio on the rotational speed of the front wheel,
• wherein when the front wheel is locked or the rotational speed of the front wheel is lower than the rear wheel, the gear shifting control is executed toward the lower gear side from the change gear ratio on the rotational speed of the rear wheel, and
• wherein a gear shift toward a shift up side is executed until a difference in rotational speed between the front wheel and the rear wheel is no longer detected.