Wheel-state obtaining apparatus, and vehicle-state obtaining apparatus

• US 7,248,953 B2
• Filed: 07/23/2003
• Issued: 07/24/2007
• Est. Priority Date: 08/14/2002
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ogawa, Atsushi
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US10/523,830
• Publication Number:
  US 20050235744A1
• Time in Patent Office: 1,462 Days
• Field of Search: None
• US Class Current: 701/29
• CPC Class Codes: B60C 23/001 Devices for manually or automatically controlling or distributing tyre pressure whilst the vehicle is moving
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0476 Temperature compensation of measured pressure values
• CPC Class Codes: B60C 23/0481 System diagnostic, e.g. monitoring battery voltage, detecting hardware detachments or identifying wireless transmission failures
• CPC Class Codes: B60C 23/0483 Wireless routers between wheel mounted transmitters and chassis mounted receivers
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A wheel-state obtaining apparatus for a vehicle, including wheel-side devices (10–16) each having an air pressure sensor (32) for detecting an air pressure of a wheel tire of the vehicle, and a body-side device (18) having receiver antennas (20–26) and arranged to receive wheel-side information from the wheel-side devices through the receiver antennas and extract air-pressure information representative of the detected air pressure, that is, detected-air-pressure information, and wherein the body-side device includes an estimating portion (54) which is operable, in the event of a failure of any of the receiver antennas to receive the wheel-side information, to estimate the tire air pressure on the basis of detected speeds of the wheel, and obtain estimated-air-pressure information representative of the estimated air pressure. Thus, the wheel-state obtaining apparatus is capable of obtaining information on the air pressure even in the event of a failure of the receiver antennas (20–26) to receive the wheel-side information.

Claims

1. A wheel-state obtaining apparatus comprising:

a wheel-side device provided for each of at least one of a plurality of wheels of a vehicle and including a first-wheel-state detecting device operable to detect a first state of the corresponding wheel and a wheel-side-information transmitting device operable to transmit, in a wireless fashion at a time interval, wheel-side information representative of said first state of said corresponding wheel detected by said first-wheel-state detecting device; and

a body-side device disposed on a body of the vehicle and including (a) a detected-information obtaining device operable to obtain detected information representative of the first state of said corresponding wheel detected by said first-wheel-state detecting device, (b) a vehicle-state detecting device operable to detect a state of the vehicle, (c) an estimated-information obtaining device operable to estimate said first state of said corresponding wheel on the basis of at least the state of the vehicle detected by said vehicle-state detecting device, and obtain estimated information representative of the estimated first state, and (d) a determining device operable to determine one of said detected information and said estimated information, as wheel-state information representative of said first state of said corresponding wheel,

and wherein said estimated-information obtaining device is operable to obtain said estimated information, during a period between a moment of last reception of said wheel-side information by said body-side device from said wheel-side-information transmitting device, and a moment which is said time interval after said moment of last reception, said determining device including a first determining portion operable to determine, as said wheel-state information, said estimated information obtained during said period.

2. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes an individually determining portion operable for each of said plurality of wheels, independently of each other, such that one of said detected information and said estimated information is determined as said wheel-state information for each of said plurality of wheels.

3. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes an overall determining portion operable for all of said plurality of wheels, such that one of said detected information and said estimated information is determined as said wheel-state information, commonly for all of said plurality of wheels.

4. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes a detection-failure estimated-information obtaining portion operable to determine said detected information as said wheel-state information when said first state of said corresponding wheel has been detected by said first-wheel-state detecting device, and determine said estimated information as said wheel-state information when said first state has not been detected by said first-wheel-state detecting device.

5. A wheel-state obtaining apparatus according to claim 1, wherein said wheel-side device further includes an electric power source operable to supply said wheel-side-information transmitting device and said first-wheel-state detecting device with an electric energy, and said body-side device further includes a receiving device operable to receive said wheel-side information transmitted from said wheel-side device, said detected-information obtaining device including a detected-information extracting portion operable to extract from said wheel-side information said detected information representative of the first state of said corresponding wheel.

6. A wheel-state obtaining apparatus according to claim 5, wherein said determining device includes a reception-condition-dependent determining portion operable to determine one of said detected information and said estimated information as said wheel-state information, on the basis of a condition of reception of said wheel-side information by said receiving device.

7. A wheel-state obtaining apparatus according to claim 5, wherein said determining device further includes a second determining portion operable to determine said estimated information as said wheel-state information when said wheel-side information has not been normally received by said receiving device, due to at least one of an abnormality of said wheel-side device, an abnormality of said receiving device, and a noise included in said wheel-side information, and determine said detected information as said wheel-state information when said wheel-side information has been normally received by said receiving device.

8. A wheel-state obtaining apparatus according to claim 7, wherein said determining portion determines said estimated information as said wheel-state information when said wheel-side information received by said receiving device is abnormal, and determines said estimated information as said wheel-state information when said wheel-state information received by said receiving device is normal.

9. A wheel-state obtaining apparatus according to claim 5, wherein said determining device includes a reception-failure estimated-information determining portion operable to determine said estimated information as said wheel-state information when said wheel-side information has not been received by said receiving device, at a predetermined timing of reception of said wheel-side information by said receiving device.

10. A wheel-state obtaining apparatus according to claim 9, wherein said wheel-side-information transmitting device includes a periodically transmitting portion operable to transmit said wheel-side information at a predetermined interval of transmission.

11. A wheel-state obtaining apparatus according to claim 5, wherein said wheel-side-information transmitting device includes a periodically transmitting portion operable to transmit said wheel-side information at a predetermined interval of transmission, and said estimated-information obtaining device is operable to obtain said estimated information during a predetermined interval of reception of said wheel-side information by said receiving device.

12. A wheel-state obtaining apparatus according to claim 5, wherein said determining device includes a reception-condition determining portion operable to determine whether a ratio of reception of said wheel-side information by said receiving device is relatively high or low, and a reception-condition-dependent determining portion operable to determine said detected information as said wheel-state information when said reception-condition determining portion determines that said ratio of reception is relatively high, and determine said estimated information as said wheel-state information when said reception-condition determining portion determines that said ratio of reception is relatively low.

13. A wheel-state obtaining apparatus according to claim 5, wherein said estimated-information obtaining device includes a detected-state estimating portion operable to estimate said first state of said corresponding wheel after last reception of said wheel-side information by said receiving device, on the basis of at least said first state of said corresponding wheel represented by the wheel-side information received last by said receiving device.

14. A wheel-state obtaining apparatus according to claim 13, wherein said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a second state of each of at least one of said plurality of wheels, said second state being different from said first state, and said detected-state estimating portion estimates said first state of said corresponding wheel, on the basis of said first state represented by the wheel-side information received last by said receiving device, and said second state detected by said second-wheel-state detecting device.

15. A wheel-state obtaining apparatus according to claim 5, wherein said wheel-side device further includes a transmission control device operable to control a state of transmission of said wheel-side information from said wheel-side-information transmitting device.

16. A wheel-state obtaining apparatus according to claim 15, wherein said transmission control device includes at least one of(a) a transmission permitting/inhibiting portion operable to permit or inhibit transmission of said wheel-side information from said wheel-side-information transmitting device, on the basis of a state of change of said first state of said corresponding wheel detected by said first-wheel-state detecting device, and (b) a transmission restricting portion operable to restrict the transmission of said wheel-side information from said wheel-side-information transmitting device, when the change of said first state detected by said first-wheel-state detecting device is slower than a predetermined threshold.

17. A wheel-state obtaining apparatus according to claim 15, wherein said wheel-side device further includes (a) a wheel-side-information generating device operable to generate said wheel-side information on the basis of said first state of said corresponding wheel detected by said first-wheel-state detecting device, and (b) a generating-device control device operable to control said wheel-side-information generating device on the basis of a state of change of said first state detected by said first-wheel-state detecting device.

18. A wheel-state obtaining apparatus according to claim 15, wherein said body-side device further includes a transmission-state-control-information generating device operable to transmit to said wheel-side device transmission-state control information indicative of a state of transmission of said wheel-side information from said wheel-side-information transmitting device, and said wheel-side device further includes a body-side-information receiving device operable to receive information from said body-side device, said transmission control device controlling said wheel-side-information transmitting device according to said transmission-state control information received by said body-side-information receiving device.

19. A wheel-state obtaining apparatus according to claim 18, wherein transmission-state-control-information transmitting device is operable to transmit to said wheel-side device at least one of (a) information which permits the transmission of said wheel-side information, and (b) information which requires the transmission of said wheel-side information, when an accuracy of said estimated information obtained by said estimated-information obtaining device is lower than a predetermined threshold.

20. A wheel-state obtaining apparatus according to claim 1, wherein said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a second state of each of at least one of said plurality of wheels, said second state being different from said first state.

21. A wheel-state obtaining apparatus according to claim 20, wherein said detected-state estimating portion includes an estimating portion operable to estimate said first state of said corresponding wheel, according to a predetermined rule on the basis of said second state of each of said at least one of said plurality of wheels detected by said second-wheel-state detecting device, and a rule-changing portion operable to change said predetermined rule on the basis of said first state of said corresponding wheel represented by said detected information which has been extracted by said detected-information obtaining device from the last received wheel-side information.

22. A wheel-state obtaining apparatus according to claim 20, wherein said detected-state estimating portion includes a provisionally estimating portion operable to obtain a provisional estimated value of said first state of said corresponding wheel on the basis of said second state of each of said at least one of said plurality of wheels detected by said second-wheel-state detecting device, and an estimated-information obtaining portion operable to compensate said provisional estimated value of said first state on the basis of said first state represented by said detected information extracted from said wheel-side information which has been received last by said receiving device, said estimated-information obtaining portion determining the compensated provisional estimated value of said first state as said estimated information.

23. A wheel-state obtaining apparatus according to claim 20, wherein said detected-state estimating portion includes a provisionally estimating portion operable to obtain a provisional estimated value of said first state of said corresponding wheel on the basis of said second state of each of said at least one of said plurality of wheels detected by said second-wheel-state detecting device, and a final-estimated-value obtaining portion operable to compensate said provisional estimated value of said first state on the basis of a predetermined relationship between said first state represented by said detected information extracted from said wheel-side information received last by said receiving device, and the provisional estimated value obtained at a moment substantially coincident with a moment at which said wheel-side information was received last by said receiving device, said final-estimated-value obtaining portion determining the compensated provisional estimated value of said first state as a final estimated value of said first state.

24. A wheel-state obtaining apparatus according to claim 1, wherein said estimated-information obtaining device includes an other-wheel-dependent estimating portion operable to estimate said first state of said corresponding wheel on the basis of said first state of at least one other wheel of said plurality of wheels, for obtaining the estimated information representative of the estimated first state.

25. A wheel-state obtaining apparatus according to claim 24, wherein said first-wheel-state detecting device is provided for each of at least two wheels of said plurality of wheels, and said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a second state of each of said at least two wheels, which second state is different from said first state, said other-wheel-dependent estimating portion obtaining said estimated information of one of two wheels of said plurality of wheels, by estimating said first state of said one of said two wheels, on the basis of said second state of said two wheels detected by said second-wheel-state detecting device, and said first state of the other of said two wheels detected by said first-wheel-state detecting device.

26. A wheel-state obtaining apparatus according to claim 1, wherein said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a second state of each of at least one of said plurality of wheels, said at least one of said plurality of wheels including another wheel different from said corresponding wheel, said second state being different from said first state, and wherein said estimated-information obtaining device includes a relation-dependent estimated-information obtaining portion operable to estimate said first state of said corresponding wheel to obtain said estimated information representative of the estimated first state of said corresponding wheel, on the basis of at least said second state of said another wheel detected by said second-wheel-state detecting device, and on the basis of a predetermined relationship between the second states of said corresponding wheel and said another wheel.

27. A wheel-state obtaining apparatus according to claim 1, wherein said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a quantity of a second state of each of at least two wheels of said plurality of wheels, said at least two wheels including said corresponding wheel, said second state being different from said first state, and wherein said estimated-information obtaining device includes an estimated-information obtaining portion operable to estimate said first state of said corresponding wheel to obtain said estimated information representative of the estimated first state of said corresponding wheel, on the basis of at least a relationship between the quantity of said second state of said corresponding wheel detected by said second-wheel-state detecting device, and an average of the quantities of said second states of said at least two wheels detected by said second-wheel-state detecting device.

28. A wheel-state obtaining apparatus according to claim 1, wherein said vehicle-state detecting device includes a second-wheel-state detecting device operable to detect a second state of said corresponding wheel, said second state being different from said first state, and said estimated-information obtaining device includes (a) a first-estimated-information obtaining portion operable to estimate said first state of said corresponding wheel on the basis of said first state of at least one other wheel of said plurality of wheels, to obtain first estimated information, and (b) a second-estimated-information obtaining portion operable to estimate said first state of said corresponding wheel on the basis of said second state of said corresponding wheel, to obtain second estimated information, and wherein said determining device includes a selecting portion operable to select one of said first estimated information and said second estimated information, when said determining device determines said estimated information as said wheel-state information.

29. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes (a) a vehicle-state detecting portion operable to detect a state of the vehicle, and (b) a vehicle-state-dependent determining portion operable to determine one of said detected information and said estimated information as said wheel-state information, on the basis of the state of the vehicle detected by said vehicle-state detecting portion.

30. A wheel-state obtaining apparatus according to claim 29, wherein said vehicle-state detecting portion includes a vehicle-running-state detecting device operable to detect a running state of the vehicle, and said vehicle-state-dependent determining portion includes a vehicle-running-state-dependent determining portion operable to determine one of said detected information and said estimated information as said wheel-state information, on the basis of the running state of the vehicle detected by said vehicle-running-state detecting portion.

31. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes (a) a roadway-surface detecting portion operable to detect a condition of a roadway surface on which the vehicle is running, and (b) a roadway-condition-dependent determining portion operable to determine one of said detected information and said estimated information as said wheel-state information, on the basis of the condition of said roadway surface detected by said roadway-surface detecting portion.

32. A wheel-state obtaining apparatus according to claim 1, wherein said determining device further includes a third determining portion operable to determine said estimated information as said wheel-state information, when a state of change of said estimated information as obtained by said estimated-information obtaining device is smaller than a predetermined state.

33. A wheel-state obtaining apparatus according to claim 1, wherein said determining device includes an independently determining portion operable to determine one of said detected information and said estimated information as said wheel-state information representative of said first state of each of said plurality of wheels, such that said detected information is selected as said wheel-state information of at least one of said plurality of wheels, while said estimated information is selected as said wheel-state information of the other of said plurality of wheels.

34. A wheel-state obtaining apparatus according to claim 1, wherein said first-wheel-state detecting device includes at least one of (a) an air-pressure-state detecting device operable to detect a state of an air pressure in a tire of said corresponding wheel, (b) a temperature-state detecting device operable to detect a state of a temperature of said tire, (c) a force-state detecting device operable to detect a state of forces acting on said corresponding wheel, and (d) a rotation-state detecting device operable to detect a state of rotation of said corresponding wheel.

35. A wheel-state obtaining apparatus according to claim 1, wherein said first-wheel-state detecting device includes an air-pressure-state detecting device operable to detect a state of an air pressure in a tire of each of at least one of said plurality of wheels, and said vehicle-state detecting device includes a speed detecting device operable to detect a rotating speed of each of at least one of said plurality of wheels, said estimated-information obtaining device including an estimated-air-pressure-information obtaining portion operable to estimate the air pressure of each of said at least one of the plurality of wheels on the basis of the rotating speed detected by said speed detecting device, to obtain estimated-air-pressure information representative of the estimated air pressure.

36. A wheel-state obtaining apparatus according to claim 1, wherein said first-wheel-state detecting device includes a temperature-state detecting device operable to detect a state of a temperature of a tire of each of at least one of said plurality of wheels, and said vehicle-state detecting device includes a running-time/distance detecting device operable to detect at least one of a cumulative running time and a cumulative running distance of the vehicle, said estimated-information obtaining device including an estimated-temperature-state-information obtaining portion operable to estimate the state of the temperature of the tire of each of said at least one of the plurality of wheels, on the basis of at least one of said cumulative running time and distance detected by said running-time/distance detecting device, to obtain estimated-temperature-state information representative of the estimated state of the temperature.

37. A wheel-state obtaining apparatus according to claim 1, wherein said first-wheel-state detecting device includes a temperature-state detecting device operable to detect a state of a temperature of a tire of each of at least one of said plurality of wheels, and said vehicle-state detecting device includes (a) a load detecting device operable to detect a load acting on each of said at least one of the plurality of wheels, (b) a running-state detecting device operable to detect a running state of the vehicle, and (c) an ambient-temperature detecting device operable to detect an ambient temperature of the vehicle, said estimated-information obtaining device including an estimated-temperature-state-information obtaining portion operable to estimate the state of the temperature of the tire of each of said at least one of the plurality of wheels, on the basis of the detected load acting on said each wheel and the detected ambient temperature and running state of the vehicle, to obtain estimated-temperature-state information representative of the estimated state of the temperature.

38. A wheel-state obtaining apparatus according to claim 1, wherein said first-wheel-state detecting device includes a force-detecting device operable to detect at least one force acting on each of at least one of said plurality of wheels, and said vehicle-state detecting device includes at least one of (a) a driving-state detecting device operable to detect a driving state of the vehicle, (b) a braking-state detecting device operable to detect a braking state of the vehicle, and (c) a turning-state detecting device operable to detect a turning state of the vehicle, said estimated-information obtaining device including an estimated-force-information obtaining portion operable to estimate said at least one force acting on each of said at least one of the plurality of wheels on the basis of at least one of the detected accelerating, braking and turning states of the vehicle, to obtain estimated-force information representative of the estimated at least one force.

39. A vehicle-state indicating apparatus comprising:

a wheel-state obtaining apparatus as defined in claim 1;

a judging device operable to determine whether said first state of said corresponding wheel is normal or not; and

an indicator device operable, when said judging device determines that said first state of said corresponding wheel is not normal, to provide an indication that said first state is not normal.

40. A vehicle-state control apparatus comprising:

a wheel-state obtaining apparatus as defined in claim 1;

an actuator portion operable to control a state of the vehicle; and

an actuator control portion operable to control said actuator portion on the basis of said first state of said corresponding wheel obtained by said wheel-state obtaining apparatus.

41. A wheel-state control apparatus comprising:

a wheel-state obtaining apparatus as defined in claim 1;

an actuator portion operable to control said first state of said corresponding wheel; and

an actuator control portion operable to control said actuator portion such that said first state of said corresponding wheel obtained by said wheel-state obtaining apparatus is held within a predetermined range.

42. A wheel-state obtaining device according to claim 1, wherein said estimated-information obtaining device obtains said estimated information at at least two points of time during said period.

43. A wheel-state obtaining apparatus comprising:

a wheel-side device provided for each of at least one of a plurality of wheels of a vehicle and including (a) a first-wheel-state detecting device operable to detect a first state of the corresponding wheel, and (b) a wheel-side-information transmitting device operable to transmit, in a wireless fashion at a time interval, wheel-side information representative of said first state of said corresponding wheel detected by said first-wheel-state detecting device; and

a body-side device disposed on a body of the vehicle and including (c) a receiving device operable to receive said wheel-side information transmitted from said wheel-side device, (d) a detected-information obtaining device operable to obtain received-information representative of the first state of said corresponding wheel, from said wheel-side information received by said receiving device, (e) a vehicle-state detecting device operable to detect a state of the vehicle, (f) an estimated-information obtaining device operable to estimate said first state of said corresponding wheel, on the basis of at least the state of the vehicle detected by said vehicle-state detecting device, and obtain estimated information representative of the estimated first state, and (g) an obtaining-device selecting portion operable to select one of said estimated-information obtaining device and said detected- information obtaining device,

and wherein said estimated-information obtaining device is operable to obtain said estimated information, during a period between of a moment of last reception of said wheel-side information by said body-side device, and a moment which is said timer interval after said moment of last reception, said obtaining-device selecting portion being operable to select said estimated- information obtaining device during said period.

44. A wheel-state obtaining device according to claim 43, wherein said estimated-information obtaining device obtains said estimated information at at least two points of time during said period.

45. A vehicle-state obtaining apparatus comprising:

a remote detecting device including a first detecting device, and a transmitting device operable to transmit, in a wireless fashion at a time interval, first-detecting-device information including information indicative of an output of said first detecting device; and

an information processing device including (a) a remote-information obtaining device including a receiving device operable to receive said first-detecting-device information transmitted in a wireless fashion from said remote detecting device, said remote-information obtaining device being operable to obtain remote information representative of a state of the vehicle, on the basis of said first-detecting-device information received by said receiving device, (b) a wire-transmission-dependent-information obtaining device including a second detecting device and operable to obtain wire-transmission-dependent information representative of said state of the vehicle, on the basis of second-detecting-device information which has been transmitted from said second detecting device through a signal line and which includes information indicative of an output of said second detecting device, and (c) an information determining device operable to determine one of said wire-transmission-dependent information and said remote information, as vehicle-state information representative of said state of the vehicle,

and wherein said wire-transmission-dependent-information obtaining device is operable to obtain said wire-transmission-dependent information, during a period between a moment of last reception of said first-detecting-device information by said remote-information receiving device, and a moment which is said time interval after said moment of last reception, said information determining device being operable to determine, as said vehicle-state information, said wire-transmission-dependent information obtained during said period.

46. A vehicle-state obtaining apparatus according to claim 45, wherein said first detecting device is operable to detect one state of said vehicle as said state of the vehicle, while said second detecting device is operable to detect another state of the vehicle which is different from said one state, and said wire-transmission-dependent-information obtaining device includes an estimating portion operable to estimate said one state of the vehicle on the basis of said another state of the vehicle detected by said second detecting device.

47. A vehicle state obtaining apparatus according to claim 45, wherein said remote detecting device is provided on a sprung member of the vehicle, while said information processing device is provided on an unsprung member of the vehicle.

48. A vehicle-state obtaining apparatus according to claim 45, wherein said remote detecting device is provided on a wheel of the vehicle.

49. A vehicle-state obtaining apparatus according to claim 45, wherein said information determining device is operable to determine said wire-transmission-dependent information as said vehicle-state information, when said remote information has not been received by said remote-information obtaining device.

50. A wheel-state obtaining device according to claim 45, wherein said wire-transmission-dependent-information obtaining device obtains said wire-transmission- dependent information at at least two points of time during said period.