METHOD FOR CONTROLLING A PROCESSOR OF AN ELECTRONIC ENCLOSURE MOUNTED ON A WHEEL OF A MOTOR VEHICLE

• US 20170361666A1
• Filed: 10/20/2015
• Published: 12/21/2017
• Est. Priority Date: 10/30/2014
• Status: Active Grant

• Current Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: GUINART, Nicolas, FUDULEA, Olivier, BOISSET, Jean-Philippe
• Granted Patent: US 10,500,909 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 2019/004 Tyre sensors other than for detecting tyre pressure
• CPC Class Codes: B60C 23/0454 Means for changing operation mode, e.g. sleep mode, factory mode or energy save mode
• CPC Class Codes: B60C 23/0459 self triggered by motion sensor
• CPC Class Codes: B60C 23/0474 Measurement control, e.g. setting measurement rate or calibrating of sensors; Further processing of measured values, e.g. filtering, compensating or slope monitoring
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: B60C 23/064 comprising tyre mounted deformation sensors, e.g. to determine road contact area
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

In a method for controlling a processor on a wheel, wheel operation parameters are calculated and transmitted to a CPU. A first default operating mode (standby mode) is defined, during which activities related to calculating and checking the characteristic data of the tread mark of the tire are deactivated, a second operating mode for detection of significant changes in the value of a characteristic datum of the tread mark, sought during the appearance, in standby mode, of at least one event likely to be preceded by a significant change in the value, and a third operating mode for calculation and transmission, to a CPU, a sequence of values representing the characteristic datum of the footprint, sought during the confirmation, in detection mode, of a significant change in the value of the characteristic datum of the tread mark, and at the end of which a switch is made into monitoring mode.

Claims

1. A method for controlling a processor (9) of an electronic enclosure (5) mounted on a wheel (2), fitted with a tire (4), of a motor vehicle (1), for the purpose of calculating operating parameters of said wheel, comprising, notably, one or more pieces of characteristic data of the contact patch of said tire on the ground, and transmitting these data toward a central unit (12) integrated into said motor vehicle, said control method comprising:

three operating modes are defined, consisting of;

a default mode, called the standby mode Mv, in which the activities of the processor (9) relating to the calculation and monitoring of the characteristic data of the tire contact patch are inactivated,

a mode called the detection mode Md, in which the processor (9) is programmed to detect a significant change in the value of a piece of characteristic data of the contact patch of the tire on the ground,

a mode called the transmission mode Md, in which the processor (9) is programmed to calculate a sequence of values representative of the characteristic data of the contact patch, and to cause these values to be transmitted to the central unit (12), in order to enable the latter to estimate a specific quantity related to the wheel (2),

and the following steps are executed, starting from a configuration of the processor in standby mode (9);

step 1;

switching to the detection mode (Md) on the appearance of at least one predetermined event that may be preceded by a significant variation of the value representative of the characteristic data of the contact patch,

step 2, calculating, in the detection mode (Md), a value representative of the characteristic data of the contact patch, and comparing this calculated value with a reference value Vref established in a preceding cycle of steps of controlling the processor (9),

step 3, (a) switching to the transmission mode (Mt) if the difference between the calculated value and the reference value Vref exceeds a predetermined threshold, or (b) switching to the standby mode (Mv) if this difference between the calculated value and the reference value Vref is below said threshold,

step 4, when a switch is made to the transmission mode in step 3(a), calculating and transmitting, in said transmission mode, a sequence of values representative of the characteristic data of the contact patch,

step 5, switching from the transmission mode to the standby mode after the transmission of the data sequence.

2. The control method as claimed in claim 1, wherein in step 1, a switch is made to the detection mode (Md) on the detection of at least one of the following events:

the start of movement of the motor vehicle (1) following the halting of the vehicle for a period exceeding a predetermined stopping time,

the variation of the pressure of the tire (4) by an absolute value greater than a predetermined threshold, while the vehicle (1) is halted,

the triggering of the switching by an external command.

3. The control method as claimed in claim 2, wherein in step 1, on the detection of either the start of movement of the vehicle (1), or a variation of the pressure of the tire (4), a switch to the detection mode is made solely if the radial acceleration of the wheel (2) is also above a predetermined threshold.

4. The control method as claimed in claim 1, wherein an information signal characteristic of the current step of the processor (9) is caused to be transmitted to the central unit (12) whenever there is a switch to the detection mode, and whenever there is a switch from the detection mode to the transmission mode (step 3a) or to the standby mode (step 3b).

5. The control method as claimed in claim 1, wherein in step 2, the calculation of a value representative of the characteristic data of the contact patch consists, in the first place, of calculating a sequence of n data, each representative of a raw value Vb of said characteristic data of the contact patch, and using these n data for the initialization of a digital filter, then using the filtered value Vf of the (n+1)-th raw value Vb for the purpose of comparison with the reference value Vref.

6. The control method as claimed in claim 5, wherein the initialization of the digital filter is divided into at least two successive steps, at the end of each of which the filtered value Vf of the next raw value Vb is compared with the reference value Vref in such a way that a switch is made to the transmission mode (step 3a) if the difference between this filtered value Vf and the reference value Vref exceeds a predetermined threshold.

7. The control method as claimed in claim 5, wherein the initialization of the digital filter is divided into at least two successive steps, at the end of each of which the filtered value Vf of the next raw value Vb is compared with the reference value Vref in such a way that a switch is made to the standby mode (step 3b) if the difference between this filtered value Vf and the reference value Vref is below a predetermined ceiling value.

8. The control method as claimed in claim 1, wherein, in step 4, the raw values Vb of the characteristic data of the contact patch are calculated, and said raw values are transmitted to the central unit (12).

9. The control method as claimed in claim 5, considered in combination, wherein in step 4, the filtered value Vf corresponding to each calculated raw value Vb is also determined.

10. The control method as claimed in claim 5, considered in combination, wherein, in step 2, the reference value Vref consists of:

the filtered value Vf of the last raw value Vb calculated during the preceding configuration in detection mode, when said preceding detection mode has been followed by a switch to the standby mode (step 3b),

the filtered value Vf of the last raw value Vb calculated during the preceding configuration in transmission mode, when said preceding detection mode has been followed by a switch to said transmission mode (step 3a).

11. The control method as claimed in claim 9, wherein in step 4, a parameter which is a function of the difference between each raw value Vb(t) and the filtered value Vf(t−

1) of the preceding raw value Vb(t−

1) is calculated, this parameter being assigned to said raw value Vb(t) as a parameter for the assessment of the quality of this raw value.

12. The control method as claimed in claim 11, wherein in step 5, a switch is made from the transmission mode to the standby mode after the transmission of a predetermined number Nt_max(Q_opt) of raw values Vb associated with a parameter Q_opt representative of a good quality of said value.

13. The control method as claimed in claim 10, wherein in step 5, the number of values representative of the characteristic data of the contact patch transmitted in transmission mode is limited to a predetermined number Nt_max of transmissions, and wherein a switch is made to the standby mode after the transmission of this predetermined number Nt_max of values.

14. The control method as claimed in claim 13, wherein after a switch to the standby mode resulting from a number Nt_max of transmissions, in the next step 2, the reference value Vref consists of the filtered value Vf of the last raw value Vb calculated during the preceding configuration in the detection mode.

15. The control method as claimed in claim 12, wherein in step 5, the number of values representative of the characteristic data of the contact patch transmitted in transmission mode is limited to a predetermined number Nt_max of transmissions, and wherein a switch is made to the standby mode after the transmission of this predetermined number Nt_max of values, and

wherein on each switch from the transmission mode to the standby mode, an information signal is advantageously caused to be transmitted to the central unit (12), specifying the event, namely a number of transmissions Nt_max reached, or a number of transmissions Nt(Q_opt) reached, responsible for said switch.

16. The control method as claimed in claim 9, wherein:

in step 4, each filtered value Vf is compared with a reference value Vref consisting of the filtered value Vf of the last raw value Vb calculated in the preceding detection mode,

in step 6, a switch is made to the detection mode if the difference between the filtered value Vf and the reference value Vref exceeds a predetermined threshold.

17. The method of claim 1, wherein the specific quantity related to the wheel is the load applied to said wheel.

18. The control method as claimed in claim 2, wherein an information signal characteristic of the current step of the processor (9) is caused to be transmitted to the central unit (12) whenever there is a switch to the detection mode, and whenever there is a switch from the detection mode to the transmission mode (step 3a) or to the standby mode (step 3b).

19. The control method as claimed in claim 3, wherein an information signal characteristic of the current step of the processor (9) is caused to be transmitted to the central unit (12) whenever there is a switch to the detection mode, and whenever there is a switch from the detection mode to the transmission mode (step 3a) or to the standby mode (step 3b).

20. The control method as claimed in claim 2, wherein in step 2, the calculation of a value representative of the characteristic data of the contact patch consists, in the first place, of calculating a sequence of n data, each representative of a raw value Vb of said characteristic data of the contact patch, and using these n data for the initialization of a digital filter, then using the filtered value Vf of the (n+1)-th raw value Vb for the purpose of comparison with the reference value Vref.