Wheel position detecting device and tire pressure detecting apparatus having the same

• US 9,757,997 B2
• Filed: 12/25/2012
• Issued: 09/12/2017
• Est. Priority Date: 12/27/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Mori, Masashi, Watabe, Nobuya, Okada, Noriaki, Sekizawa, Takatoshi
• Primary Examiner(s): Lee, Paul D
• Application Number:
  US14/368,257
• Publication Number:
  US 20140365162A1
• Time in Patent Office: 1,722 Days
• Field of Search: 702138
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: B60C 23/0489 for detecting the actual angular position of the monitoring device while the wheel is turning
• CPC Class Codes: G01P 15/003 Kinematic accelerometers, i.e. measuring acceleration in relation to an external reference frame, e.g. Ferratis accelerometers G01P15/001, G01P15/16, G01P15/165 take precedence
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence

Abstract

In a wheel position detecting device, a transmission angular position of a transmitter to transmit a frame from the transmitter to a receiver is changed by a predetermined angle each time the transmitter transmits the frame. A receiver acquires gear information indicating a tooth position of a gear rotating in association with a corresponding wheel, based on a detection signal of a wheel speed sensor. The receiver specifies to which wheels the transmitter is integrated, based on the tooth position of the gear at a reception timing of the frame.

Claims

1. A wheel position detecting device for a vehicle having a vehicle body and a plurality of wheels, the wheel position detecting device comprising:

a transmitter being integrated to each of the plurality of wheels, the transmitter including a first control unit, the first control unit generating and transmitting a frame including an identification information specific to the transmitter; and

a receiver being integrated to the vehicle body, the receiver including an antenna and a second control unit, the second control unit receiving the frame transmitted from the transmitter through the antenna, the second control unit performing a wheel position detection to specify which of the plurality of wheels the transmitter transmitting the frame is integrated to and to store a relationship between the identification information of the transmitter and a corresponding wheel to which the transmitter is integrated, wherein

the transmitter includes an acceleration sensor that outputs a detection signal according to an acceleration containing a gravitational acceleration component that varies with rotation of the corresponding wheel to which the transmitter is integrated,

the first control unit detects an angular position of the transmitter relative to a reference position, based on the gravitational acceleration component provided by the detection signal of the acceleration sensor, the reference position being set at any position in a circumferential direction of the corresponding wheel,

the first control unit transmits the frame when the transmitter is at a transmission angular position, and

the first control unit changes the transmission angular position by a predetermined angle each time the frame is transmitted,

the wheel position detecting device further comprising;

a wheel speed sensor being disposed to correspond to each of the wheels to detect a tooth of a gear that rotates in association with the corresponding wheel, the gear including conductive portions as teeth and intermediate portions between the conductive potions, the intermediate portions having a magnetic resistance different from the conductive portions, wherein

the second control unit acquires a gear information indicating a tooth position of the gear based on a detection signal of the wheel speed sensor,

the second control unit specifies which of the plurality of wheels the transmitter is integrated to based on the tooth position of the gear at a reception timing of the frame,

the second control unit sets a variation allowance range of the tooth position based on the tooth position of the gear at the reception timing of the frame,

the second control unit determines whether the tooth position of the gear at a subsequent reception timing of the frame is within the variation allowance range,

when the tooth position of the gear at the subsequent reception timing is not within the variation allowance range, the second control unit excludes the wheel corresponding to the gear from candidate wheels until one wheel remains, and registers the one wheel as the wheel to which the transmitter is integrated,

the second control unit changes the variation allowance range each time the frame is received,

the second control unit sets an overlapping range between the variation allowance range and a previous variation allowance range set based on the tooth position of the gear at a previous reception timing of the frame, as a new variation allowance range,

the second control unit corrects the tooth position of the gear detected at the reception timing associated with the frame that is transmitted at a transmission angular position changed by the first control unit to a tooth position associated with a frame that is transmitted at a fixed transmission angular position, and

the second control unit determines whether the teeth position of the gear corrected is within the variation allowance range, to specify the wheel to which the transmitter is integrated.

2. The wheel position detecting device according to claim 1, wherein

the second control unit increases the variation allowance range with an increase in a vehicle speed.

3. The wheel position detecting device according to claim 1, wherein

the first control unit generates the frame including data for determining the variation allowance range set by the second control unit.

4. A tire pressure detecting apparatus comprising:

the wheel position detecting device according to claim 1, wherein

the transmitter includes a sensing unit that outputs a detection signal according to a tire pressure of the corresponding wheel,

the first control unit generates a tire pressure information indicating the detection signal of the sensing unit,

the first control unit includes the tire pressure information in the frame, and transmits the frame, and

the second control unit detects the tire pressure of each wheel based on the tire pressure information included in the frame.

5. A wheel position detecting device for a vehicle having a vehicle body and a plurality of wheels, the wheel position detecting device comprising:

a transmitter being integrated to each of the plurality of wheels, the transmitter including a first control unit, the first control unit generating and transmitting a frame including an identification information specific to the transmitter; and

a receiver being integrated to the vehicle body, the receiver including an antenna and a second control unit, the second control unit receiving the frame transmitted from the transmitter through the antenna, the second control unit performing a wheel position detection to specify which of the plurality of wheels the transmitter transmitting the frame is integrated to and to store a relationship between the identification information of the transmitter and a corresponding wheel to which the transmitter is integrated, wherein

the transmitter includes an acceleration sensor that outputs a detection signal according to an acceleration containing a gravitational acceleration component that varies with rotation of the corresponding wheel to which the transmitter is integrated,

the first control unit detects an angular position of the transmitter relative to a reference position, based on the gravitational acceleration component provided by the detection signal of the acceleration sensor, the reference position being set at any position in a circumferential direction of the corresponding wheel,

the first control unit transmits the frame when the transmitter is at a transmission angular position, and

the first control unit changes the transmission angular position by a predetermined angle each time the frame is transmitted,

the wheel position detecting device further comprising;

a wheel speed sensor being disposed to correspond to each of the wheels to detect a tooth of a gear that rotates in association with the corresponding wheel, the gear including conductive portions as teeth and intermediate portions between the conductive potions, the intermediate portions having a magnetic resistance different from the conductive portions, wherein

the second control unit acquires a gear information indicating a tooth position of the gear based on a detection signal of the wheel speed sensor,

the second control unit specifies which of the plurality of wheels the transmitter is integrated to based on the tooth position of the gear at a reception timing of the frame,

the second control unit stores the predetermined angle changed by the first control unit,

the second control unit measures a time elapsed since the transmitter begins to transmit the frame, as an elapsed time,

the second control unit estimates the transmission angular position of the transmitter at the reception timing of the frame based on the elapsed time, and

the second control unit corrects the tooth position of the gear detected at the reception timing associated with the frame that is transmitted at a transmission angular position changed by the first control unit to a tooth position associated with a frame that is transmitted at a fixed transmission angular position.

6. A wheel position detecting device for a vehicle having a vehicle body and a plurality of wheels, the wheel position detecting device comprising:

a transmitter being integrated to each of the plurality of wheels, the transmitter including a first control unit, the first control unit generating and transmitting a frame including an identification information specific to the transmitter; and

a receiver being integrated to the vehicle body, the receiver including an antenna and a second control unit, the second control unit receiving the frame transmitted from the transmitter through the antenna, the second control unit performing a wheel position detection to specify which of the plurality of wheels the transmitter transmitting the frame is integrated to and to store a relationship between the identification information of the transmitter and a corresponding wheel to which the transmitter is integrated, wherein

the transmitter includes an acceleration sensor that outputs a detection signal according to an acceleration containing a gravitational acceleration component that varies with rotation of the corresponding wheel to which the transmitter is integrated,

the first control unit detects an angular position of the transmitter relative to a reference position, based on the gravitational acceleration component provided by the detection signal of the acceleration sensor, the reference position being set at any position in a circumferential direction of the corresponding wheel,

the first control unit transmits the frame when the transmitter is at a transmission angular position, and

the first control unit changes the transmission angular position by a predetermined angle each time the frame is transmitted,

the wheel position detecting device further comprising;

a wheel speed sensor being disposed to correspond to each of the wheels to detect a tooth of a gear that rotates in association with the corresponding wheel, the gear including conductive portions as teeth and intermediate portions between the conductive potions, the intermediate portions having a magnetic resistance different from the conductive portions, wherein

the second control unit acquires a gear information indicating a tooth position of the gear based on a detection signal of the wheel speed sensor,

the second control unit specifies which of the plurality of wheels the transmitter is integrated to based on the tooth position of the gear at a reception timing of the frame,

the first control unit generates the frame including a transmission count representing a number of times of frame transmission, and

the second control unit corrects the tooth position of the gear detected at the reception timing associated with the frame that is transmitted at a transmission angular position changed by the first control unit to a tooth position associated with a frame transmitted at a fixed transmission angular position, based on the transmission count.

7. A wheel position detecting device for a vehicle having a vehicle body and a plurality of wheels, the wheel position detecting device comprising:

a transmitter being integrated to each of the plurality of wheels, the transmitter including a first control unit, the first control unit generating and transmitting a frame including an identification information specific to the transmitter; and

a receiver being integrated to the vehicle body, the receiver including an antenna and a second control unit, the second control unit receiving the frame transmitted from the transmitter through the antenna, the second control unit performing a wheel position detection to specify which of the plurality of wheels the transmitter transmitting the frame is integrated to and to store a relationship between the identification information of the transmitter and a corresponding wheel to which the transmitter is integrated, wherein

the transmitter includes an acceleration sensor that outputs a detection signal according to an acceleration containing a gravitational acceleration component that varies with rotation of the corresponding wheel to which the transmitter is integrated,

the first control unit detects an angular position of the transmitter relative to a reference position, based on the gravitational acceleration component provided by the detection signal of the acceleration sensor, the reference position being set at any position in a circumferential direction of the corresponding wheel,

the first control unit transmits the frame when the transmitter is at a transmission angular position, and

the first control unit changes the transmission angular position by a predetermined angle each time the frame is transmitted,

the wheel position detecting device further comprising;

a wheel speed sensor being disposed to correspond to each of the wheels to detect a tooth of a gear that rotates in association with the corresponding wheel, the gear including conductive portions as teeth and intermediate portions between the conductive potions, the intermediate portions having a magnetic resistance different from the conductive portions, wherein

the second control unit acquires a gear information indicating a tooth position of the gear based on a detection signal of the wheel speed sensor,

the second control unit sets a variation allowance range of the tooth position based on the tooth position of the gear at the reception timing of the frame,

the second control unit of the receiver determines whether the tooth position of the gear at a subsequent reception timing of the frame is within the variation allowance range,

when the tooth position of the gear at the subsequent reception timing is not within the variation allowance range, the second control unit excludes the wheel corresponding to the gear from candidate wheels until one wheel remains, and registers the one wheel as the wheel to which the transmitter is integrated,

the second control unit changes the variation allowance range each time the frame is received,

the second control unit calculates an overlapping range between the variation allowance range and a first added variation allowance range that is provided by adding a predetermined variation allowance range to a previous variation allowance range set at a previous reception timing of the frame, and

the second control unit sets a second added variation allowance range that is provided by adding the predetermined variation allowance range to the overlapping range calculated, as a new variation allowance range.