Tire-pressure control apparatus

• US 8,013,724 B2
• Filed: 08/10/2007
• Issued: 09/06/2011
• Est. Priority Date: 09/29/2006
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Isono, Hiroshi
• Primary Examiner(s): Nguyen; John
• Assistant Examiner(s): FEI, JORDAN S
• Application Number:
  US12/090,492
• Publication Number:
  US 20090048733A1
• Time in Patent Office: 1,488 Days
• Field of Search: 340/442, 340/443, 340/444, 152/416, 152/417, 152/418, 152/419, 731/46, 731/462, 701/69, 156/110.1, 156/157, 156/317, 156/416
• US Class Current: 340/442
• CPC Class Codes: B60C 23/004 the control being done on the wheel, e.g. using a wheel-mounted reservoir
• CPC Class Codes: B60C 23/127 the pumps being mounted on the hubs
• CPC Class Codes: B60C 23/137 comprising cam driven pistons

Abstract

A tire-pressure control apparatus includes time calculation means for calculating an up time over which the tire pressure of each wheel increases from a lower limit set value to an upper limit set value and a down time over which the tire pressure of the wheel decreases from the upper limit set value to the lower limit set value, on the basis of the detection value of a corresponding pressure sensor; average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the up time on the basis of the detection value of a corresponding wheel speed sensor; first-pump-supplied-air-quantity calculation means (403) for calculating a first pump-supplied air quantity Qvw* of a corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the average rotational speed; second-pump-supplied-air-quantity calculation means (404) for calculating a second pump-supplied air quantity Qp* of the air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the down time; and determination means (405) for comparing the first pump-supplied air quantity Qvw* and the second pump-supplied air quantity Qp*.

Claims

1. A tire-pressure control apparatus comprising a plurality of wheel speed sensors for respectively detecting rotational speeds of a plurality of wheels of a vehicle;

a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value; and

a plurality of pressure sensors respectively detecting the tire pressures of the plurality of wheels, the tire-pressure control apparatus further comprising for each wheel;

up-time calculation means for calculating an up time, which is a time period over which the tire pressure of the wheel increases from the lower limit set value to the upper limit set value, on the basis of a detection value of the corresponding pressure sensor;

down-time calculation means for calculating a down time, which is a time period over which the tire pressure of the wheel decreases from the upper limit set value to the lower limit set value, on the basis of the detection value of the pressure sensor;

average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the up time calculated by the up-time calculation means, on the basis of the detection value of the wheel speed sensor;

first-pump-supplied-air-quantity calculation means for calculating a first pump-supplied air quantity of the corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the average rotational speed;

second-pump-supplied-air-quantity calculation means for calculating a second pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the down time; and

determination means for comparing the first pump-supplied air quantity and the second pump-supplied air quantity.

2. A tire-pressure control apparatus comprising a plurality of wheel speed sensors for respectively detecting rotational speeds of a plurality of wheels of a vehicle;

a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value; and

a plurality of pressure sensors respectively detecting the tire pressures of the plurality of wheels, the tire-pressure control apparatus further comprising for each wheel;

wheel-speed-sensor determination means for determining whether the corresponding wheel speed sensor is normal or anomalous on the basis of a detection value of the wheel speed sensor;

up-time calculation means for calculating an up time, which is a time period over which the tire pressure of the wheel increases from the lower limit set value to the upper limit set value, on the basis of a detection value of the corresponding pressure sensor;

down-time calculation means for calculating a down time, which is a time period over which the tire pressure of the wheel decreases from the upper limit set value to the lower limit set value, on the basis of the detection value of the pressure sensor;

average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the up time calculated by the up-time calculation means, on the basis of the detection value of the wheel speed sensor;

first-pump-supplied-air-quantity calculation means for calculating a first pump-supplied air quantity of the corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the average rotational speed;

second-pump-supplied-air-quantity calculation means for calculating a second pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the down time; and

system determination means, operable when the wheel-speed-sensor determination means determines that the corresponding wheel speed sensor is normal, for determining whether the air pressure generation unit and the pressure sensor are normal or anomalous on the basis of the difference between the first pump-supplied air quantity and the second pump-supplied air quantity.

3. A tire-pressure control apparatus comprising a plurality of wheel speed sensors for respectively detecting rotational speeds of a plurality of wheels of a vehicle;

a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value;

a plurality of pressure sensors respectively detecting the tire pressures of the plurality of wheels; and

a plurality of mode sensors each detecting whether the corresponding air pressure generation unit is in a generation-state or in a non-generation state, the tire-pressure control apparatus further comprising for each wheel;

wheel-speed-sensor determination means for determining whether the corresponding wheel speed sensor is normal or anomalous on the basis of a detection value of the wheel speed sensor;

up-time calculation means for calculating an up time, which is a time period over which the tire pressure of the wheel increases from the lower limit set value to the upper limit set value, on the basis of a detection value of the corresponding pressure sensor;

down-time calculation means for calculating a down time, which is a time period over which the tire pressure of the wheel decreases from the upper limit set value to the lower limit set value, on the basis of the detection value of the pressure sensor;

average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the up time calculated by the up-time calculation means, on the basis of the detection value of the wheel speed sensor;

first-pump-supplied-air-quantity calculation means for calculating a first pump-supplied air quantity of the corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the average rotational speed;

second-pump-supplied-air-quantity calculation means for calculating a second pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the down time;

generation-state-maintaining-time calculation means for calculating a generation-state maintaining time, in which the air pressure generation unit is maintained in a generation state, on the basis of a detection value of the corresponding mode sensor;

non-generation-state-maintaining-time calculation means for calculating a non-generation-state maintaining time, in which the air pressure generation unit is maintained in a non-generation state, on the basis of the detection value of the mode sensor;

third-pump-supplied-air-quantity calculation means for calculating a third pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the non-generation-state maintaining time;

system determination means, operable when the wheel-speed-sensor determination means determines that the corresponding wheel speed sensor is normal, for determining whether the corresponding air pump and the corresponding pressure sensor are normal or anomalous on the basis of the difference between the first pump-supplied air quantity and the second pump-supplied air quantity;

mode determination means, operable when the system determination means determines that the air pump and the pressure sensor are normal, for determining whether the corresponding mode sensor is normal or anomalous on the basis of the difference between the first pump-supplied air quantity and the third pump-supplied air quantity; and

air-pump/pressure-sensor determination means, operable when the system determination means determines that either of the air pump and the pressure sensor is anomalous, for determining which one of the air pump and the pressure sensor is anomalous on the basis of the difference between the first pump-supplied air quantity and the third pump-supplied air quantity.

4. A tire-pressure control apparatus comprising a plurality of wheel speed sensors for respectively detecting rotational speeds of a plurality of wheels of a vehicle;

a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value; and

a plurality of mode sensors each detecting whether the corresponding air pressure generation unit is in a generation-state or in a non-generation state, the tire-pressure control apparatus further comprising for each wheel;

generation-state-maintaining-time calculation means for calculating a generation-state maintaining time, in which the air pressure generation unit is maintained in a generation state, on the basis of a detection value of the corresponding mode sensor;

non-generation-state-maintaining-time calculation means for calculating a non-generation-state maintaining time, in which the air pressure generation unit is maintained in a non-generation state, on the basis of the detection value of the mode sensor;

average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the generation-state maintaining time calculated by the generation-state-maintaining-time calculation means, on the basis of the detection value of the wheel speed sensor;

fourth-pump-supplied-air-quantity calculation means for calculating a fourth pump-supplied air quantity of the corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the average rotational speed;

third-pump-supplied-air-quantity calculation means for calculating a third pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the non-generation-state maintaining time; and

determination means for comparing the fourth pump-supplied air quantity and the third pump-supplied air quantity.

5. A tire-pressure control apparatus comprising a plurality of wheel speed sensors for respectively detecting rotational speeds of a plurality of wheels of a vehicle;

a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value; and

a plurality of mode sensors each detecting whether the corresponding air pressure generation unit is in a generation-state or in a non-generation state, the tire-pressure control apparatus further comprising for each wheel;

wheel-speed-sensor determination means for determining whether the corresponding wheel speed sensor is normal or anomalous on the basis of a detection value of the wheel speed sensor;

generation-state-maintaining-time calculation means for calculating a generation-state maintaining time, in which the air pressure generation unit is maintained in a generation state, on the basis of a detection value of the corresponding mode sensor;

non-generation-state-maintaining-time calculation means for calculating a non-generation-state maintaining time, in which the air pressure generation unit is maintained in a non-generation state, on the basis of the detection value of the mode sensor;

average-rotational-speed calculation means for calculating an average rotational speed of the wheel during the generation-state maintaining time calculated by the generation-state-maintaining-time calculation means, on the basis of the detection value of the wheel speed sensor;

fourth-pump-supplied-air-quantity calculation means for calculating a fourth pump-supplied air quantity of the corresponding air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the average rotational speed;

third-pump-supplied-air-quantity calculation means for calculating a third pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the non-generation-state maintaining time; and

system determination means, operable when the wheel-speed-sensor determination means determines that the corresponding wheel speed sensor is normal, for determining whether the air pressure generation unit and the mode sensor are normal or anomalous on the basis of the difference between the fourth pump-supplied air quantity and the third pump-supplied air quantity.

6. A tire-pressure control apparatus comprising a plurality of air pressure generation units respectively provided for the plurality of wheels and each including an air pump driven through rotation of the corresponding wheel so as to generate compressed air to be supplied to a tire air chamber of the wheel and being capable of maintaining a tire pressure of the wheel between a lower limit set value and an upper limit set value;

a plurality of pressure sensors respectively detecting the tire pressures of the plurality of wheels; and

a plurality of mode sensors each detecting whether the corresponding air pressure generation unit is in a generation-state or in a non-generation state, the tire-pressure control apparatus further comprising for each wheel;

up-time calculation means for calculating an up time, which is a time period over which the tire pressure of the wheel increases from the lower limit set value to the upper limit set value, on the basis of a detection value of the corresponding pressure sensor;

down-time calculation means for calculating a down time, which is a time period over which the tire pressure of the wheel decreases from the upper limit set value to the lower limit set value, on the basis of the detection value of the pressure sensor;

second-pump-supplied-air-quantity calculation means for calculating a second pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the up time and the down time;

generation-state-maintaining-time calculation means for calculating a generation-state maintaining time, in which the air pressure generation unit is maintained in a generation state, on the basis of a detection value of the corresponding mode sensor;

non-generation-state-maintaining-time calculation means for calculating a non-generation-state maintaining time, in which the air pressure generation unit is maintained in a non-generation state, on the basis of the detection value of the mode sensor;

third-pump-supplied-air-quantity calculation means for calculating a third pump-supplied air quantity of the air pressure generation unit in a single generation and non-generation cycle on the basis of the generation-state maintaining time and the non-generation-state maintaining time; and

determination means for comparing the second pump-supplied air quantity and the third pump-supplied air quantity.