WO2023186494A1

WO2023186494A1 - An apparatus and method for tire pressure abnormality detection in a vehicle

Info

Publication number: WO2023186494A1
Application number: PCT/EP2023/056217
Authority: WO
Inventors: Johnson Xavier SALDANHA; Palghat Sitaram AVINASH; Satish Arvind; Cheradiyaniyil Abhijith SABU; Abhinav Prithviraj Rao
Original assignee: Robert Bosch Gmbh; Bosch Limited
Priority date: 2022-03-30
Filing date: 2023-03-10
Publication date: 2023-10-05

Abstract

The apparatus (120) comprises at least one controller configured to, receive input signals from wheel speed sensors (102), (104) of a front wheel and a rear wheel while the vehicle (100) is in motion. The controller measures and calculates parameters comprising vehicle speed, acceleration, i.e. rate of change of vehicle speed, and wheel speed difference between the front wheel and the rear wheel based on the received input signals. The controller checks associated entry conditions to initiate the tire pressure abnormality detection, characterized in that, the controller configured to calculate a long moving average and a short moving average of the wheel speed differences when the entry conditions are satisfied. The controller further detects tire pressure abnormality based on divergence between the long moving average and the short moving average. A real-time puncture detection apparatus (120) and method for two-wheelers without using tire pressure sensors is disclosed.

Description

1. Title of the Invention:

AN APPARATUS AND METHOD FOR TIRE PRESSURE

ABNORMALITY DETECTION IN A VEHICLE

2. Applicants: a. Name: Bosch Limited

Nationality: INDIA

Address: Post Box No 3000, Hosur Road, Adugodi, Bangalore

- 560030, Karnataka, India b. Name: Robert Bosch GmbH

Nationality: GERMANY

Address: Stuttgart, Feuerbach, Germany

Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed: Field of the invention:

[0001] The present invention relates to an apparatus and method for tire pressure abnormality detection in a vehicle.

Background of the invention:

[0002] An optimum tire pressure level is important for ride performance, vehicle condition and most importantly, rider safety. Thus, a system which can estimate tire pressure (at least sub-critical conditions) at a very low cost and inform the rider of the same creates tangible value. Further there is a constraint of not knowing the true speed of the vehicle (unless vehicle has an accurate GPS) as vehicle speed as measured by onboard sensors is derived from tire angular speeds, which are itself compromised in the case of deflation.

[0003] A patent literature US2002194904 discloses apparatus and method for detecting decrease in air-pressure for use in two-wheeled vehicle, and program for judging decompression for use in two-wheeled vehicle. An apparatus for detecting decrease in air-pressure for use in a two-wheeled vehicle including: a wheel speed detecting means for detecting wheel speeds; an acceleration calculating means for obtaining accelerations of a vehicle body of the two-wheeled vehicle; a slip rate calculating means for calculating slip rates when the acceleration of the vehicle body is in a specified range which is proximate to zero; an average value calculating means for obtaining average values of the slip rates and average vehicle body speeds; a difference calculating means for obtaining differences between the average values of the slip rates and a reference value which is based on an average vehicle body speed as preliminarily set when an internal pressure is normal; and a means forjudging decrease in internal pressure. A decrease in air-pressure in a twowheeled vehicle can be judged so as to enable safe driving.

Brief description of the accompanying drawings:

[0004] An embodiment of the disclosure is described with reference to the following accompanying drawing, [0005] Fig. 1 illustrates a block diagram of an apparatus for pressure abnormality detection in a vehicle, according to an embodiment of the present invention, and [0006] Fig. 2 illustrates a method for detecting tire pressure abnormality in the vehicle, according to the present invention.

Detailed description of the embodiments:

[0007] Fig. 1 illustrates a block diagram of an apparatus for pressure abnormality detection in a vehicle, according to an embodiment of the present invention. The apparatus 120 comprises at least one controller configured to, receive input signals from wheel speed sensors 102, 104 of a front wheel and a rear wheel while the vehicle 100 is in motion. The controller measures and calculates parameters comprising vehicle speed, acceleration, i.e. rate of change of vehicle speed, and wheel speed difference between the front wheel and the rear wheel based on the received input signals. The controller checks associated entry conditions to initiate the tire pressure abnormality detection. The entry conditions corresponds to checking values of one or more parameters comprising the acceleration, vehicle speed and the wheel speed difference or slip with respective threshold values or range or requirement of sufficient dataset is met to ensure that the tire pressure abnormality is ready to be determined. In other words, the entry conditions are range limits on at least one parameter comprising the acceleration, speed, individual wheel accelerations and wheel speed difference to disregard issues such as slip, tire dilation, transients, load transfer, etc. The apparatus 120 characterized in that, the controller configured to calculate a long moving average and a short moving average of the wheel speed differences when the entry conditions are satisfied. The controller further detects tire pressure abnormality based on divergence between the long moving average and the short moving average.

[0008] In accordance to an embodiment of the present invention, the long moving average and the short moving average are used in a context of Moving Average Convergence Divergence (MACD) to detect a sustaining shift in wheel speed difference. The wheel speed difference is affected by many factors like slip, steering, and also tire pressure. But unlike other dependencies, tire deflation causes a sustaining shift in wheel speed difference (not transient or momentary). This kind of shift is detected with MACD. For example, consider long moving averaging window of thirty seconds and a short moving average window of ten seconds. If there is a divergence between the two averages, then a sustaining shift is determined that lasted at least in the order of ten-thirty seconds.

[0009] According to the present invention, for detection of the tire pressure abnormality, the controller configured to check if the divergence exceeds a threshold divergence value, and while the divergence exceeds the threshold divergence value, the controller calculates a deviation between a saturated wheel speed difference value with a calibratable base value after elapse of an estimated time for reconvergence. The controller confirms detection of the tire pressure abnormality when the divergence is sustained beyond the threshold deviation. The current wheel speed difference is the saturated/stable wheel speed difference, i.e. wheel speed difference calculated based on minimum number of datasets. The wheel speed difference is a noisy signal, i.e. the difference rises and falls instantaneously. Thus the ‘saturated wheel speed difference’ is used to refer to a sustaining baseline shift in wheel speed difference values.

[0010] In accordance to an embodiment of the present invention, the apparatus 120 is at least one selected from a group comprising an internal device comprising an Electronic Control Unit (ECU) 110 of the vehicle 100, and an external device comprising a cloud based device 108 and a communication device 112 and a combination thereof. The internal device denotes that the device is internal or part of the vehicle 100. Similarly, the external device denotes that the device is externally interfaced with the vehicle 100 and is generally not part of the vehicle 100. The ECU 110 (or controller) is at least one of an Engine Management System (EMS) controller, a Tire Pressure Monitoring System (TPMS) controller, a Telematics Control Unit (TCU) controller, an Anti-lock Braking System (ABS) controller, an Electronic Stability Program (ESP) controller, and a combination thereof. The communication device 112 corresponds to electronic computing devices which enable a rider or driver or a user to communicate with others such as smartphone, wearable electronics such as smart watch, etc. The cloud based device 108 corresponds to cloud computing architecture having network of servers, databases connected with each other and vehicle 100 for processing of inputs and providing outputs.

[0011] According to an embodiment of the present invention, the apparatus 120 is implementable in different manners or scenarios. In a first scenario, the apparatus 120 is just the ECU 110 of the vehicle 100. Thus, the tire pressure abnormality is determined and then indicated to the driver directly by the ECU 110 of the vehicle 100. In a second scenario, the apparatus 120 is the external device, i.e. at least one of the cloud based device 108 and the communication device 112 of the driver who drives the vehicle 100. The input signals are transmitted to the cloud based device 108 and the communication device 112 through the TCU through wired or wireless means as known in the art. In a third scenario, the apparatus 120 is combination of the internal device and external device, i.e. the apparatus 120 is combination of the ECU 110 and the cloud based device 108, or combination of the ECU 110 and the communication device 112 or combination of the cloud based device 108 and the communication device 112 or the combination of the ECU 110, the cloud based device 108 and the communication device 112. The second scenario and the third scenario are explained later.

[0012] The apparatus 120 which is at least one of the ECU 110 or controller, the cloud based device 108 and the communication device 112 refers to computing devices/units comprising components such as memory element 106 such as Random Access Memory (RAM) and/or Read Only Memory (ROM), Analog-to- Digital Converter (ADC), Digital-to- Analog Convertor (DAC), clocks, timers and a processor (such as Central Processing Unit (CPU)) (capable of implementing machine learning) connected with the each other and to other components through communication bus channels. The components mentioned are just for understanding and may have more or less components as per requirement. The memory element 106 of the apparatus 120 is prestored with logics or instructions or programs or applications or thresholds or values which is accessed by the at least one processor as per the defined routines. The internal components of the controller are not explained for being state of the art, and the same must not be understood in a limiting manner. The apparatus 120 is capable to communicate through wired and wireless means such as but not limited to Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, Universal Serial Bus (USB) cable, micro-USB, and the like.

[0013] In accordance to an embodiment of the present invention and as per the second scenario, the apparatus 120 is the external device, i.e. any one of the cloud based device 108 and the communication device 112. For ease of understanding, the apparatus 120 is now explained as the cloud based device 108, but the same explanation is applicable when the external device is the communication device 112. When the apparatus 120 is the cloud based device 108, the cloud based device 108 receives all the tire pressure monitoring related signals (input signals) directly from the ECU 110. The ECU 110 does not process the input signals and directly transmits the input signal to the cloud based device 108 through the TCU or through the communication device 112. The cloud based device 108 is configured to receive the input signals from the ECU 110 comprising wheel speeds for the front wheel and the rear wheel, calculate the vehicle speed, acceleration and wheel speed differences and check corresponding entry conditions and calculates the long moving average and the short moving average.

[0014] The cloud based device 108 detects tire pressure abnormality based on divergence between the long moving average and the short moving average, and then transmits the results back to the ECU 110 of the vehicle 100, where the tire pressure abnormality is indicated to the driver through any output means 114 such as audio, visual (such as blinking pattern or colors), display (such as instrument cluster), haptic and combination thereof. [0015] Similarly, when the apparatus 120 is the communication device 112, the communication device 112 is connected to the ECU 110 through suitable communication or networking means as described before, such as but not limited to Bluetooth™, Wi-Fi, cables, etc. The application installed in the communication device 112 processes the input signals received from the ECU 110 and sends back the result for display to the driver. Also, the application stores the result internally for display to the driver for later reference.

[0016] In accordance to an embodiment of the present invention and as per the third scenario, the apparatus 120 is combination of internal device (the ECU 110) and the external device. The processing of the input signals is shared among the internal device(s) and the external device(s), and the result is finally displayed on the vehicle 100 (such as on the dashboard, or the instrument cluster) or used/displayed in the communication device 112. When the apparatus 120 is the external device, the external device receives the input signals from the ECU 110 comprising wheel speeds for the front wheel and the rear wheel. The inputs signals are received for at least a minimum required datasets are met, such as 1500 datasets of the wheel speeds for each of the front wheel and the rear wheel. For example, consider the apparatus 120 as combination of the ECU 110 and the cloud based device 108. The ECU 110 pre-processes the input signals (wheel speed signals) and identifies the minimum datasets satisfying the entry conditions, and sends only those inputs signals (datasets) to the cloud based device 108. Now, the cloud based device 108 processes on reduced and essential number of input signals thus providing faster results back to the vehicle 100. The apparatus 120 indicates the tire pressure abnormality at any one of during a driving of the vehicle 100 and after end of the driving.

[0017] Further, the vehicle 100 is any one selected from a group comprising a twowheeler such as scooter, motorcycle, a three-wheeler such as autorickshaw, a four wheeler such as cars, and multi-wheel vehicles 100. The tire pressure abnormality relates to at least one of a puncture and a leakage. The puncture is a slow puncture. Further, the vehicle 100 is either internal combustion engine based or electric vehicle or hybrid vehicle.

[0018] Fig. 2 illustrates a method for detecting a tire pressure abnormality in the vehicle, according to the present invention. The method comprises the plurality of steps, of which a step 202 comprises receiving and measuring wheel speeds of the front wheel and the rear wheel of the vehicle 100 using respective wheel speed sensors 102, 104 as input signals while the vehicle 100 is in motion. A step 204 comprises calculating parameters comprising vehicle speed, acceleration and wheel speed difference of the front wheel and the rear wheel using at least one of the wheel speed sensors 102, 104, and checking associated entry conditions. The method is characterized by, a step 206 comprising calculating the long moving average and the short moving average of the wheel speed differences when the entry conditions are satisfied. A step 208 comprises detecting tire pressure abnormality based on divergence between the long moving average and short moving average. Basically, a MACD is used by the method.

[0019] According to the present invention, for detecting the tire pressure abnormality, a step 210 comprises checking if the divergence exceeds a threshold divergence value, and while the divergence exceeds the threshold divergence value, a step 212 comprises calculating the deviation between the saturated wheel speed difference value with the calibratable base value after elapse of an estimated time for reconvergence. A step 214 comprises confirming detection of the tire pressure abnormality when the deviation is more than threshold deviation. The method is executed by the apparatus 120. The tire pressure abnormality relates to at least one of a puncture and a leakage. The puncture is a slow puncture, for example and not limited to, in a tubeless tires of the vehicle 100.

[0020] The method is executed by at least one apparatus 120 selected from a group comprising the internal device such as an Electronic Control Unit (ECU) 110 of the vehicle 100, and the external device comprising at least one of the cloud based device 108 and the communication device 112. A portable computing device is equally usable in place of the communication device 112. The ECU 110 is at least one of the Engine Management System (EMS) controller, the Tire Pressure Monitoring System (TPMS) controller, the Telematics Control Unit (TCU) controller, the Anti-lock Braking System (ABS) controller, the Electronic Stability Program (ESP) controller and the combination thereof. Further, when the apparatus 120 is the external device, the external device is configured to receive only those input signals from the ECU 110 which satisfies the entry conditions. The inputs signals are received until at least a minimum required datasets are met.

[0021] In accordance to an embodiment of the present invention, an indirect tire pressure abnormality for two-wheelers with wheel speed data using radial tire dynamics is provided. In addition, a real-time puncture detection apparatus 120 and method for two-wheelers without using tire pressure sensors is disclosed. The present invention provides safety /maintenance feature which uses wheel speed data and checks for abnormalities over some time to ascertain if it is due to pressure loss in one of the tires, specifically if the tire has punctured while riding. The present invention is preferably for radial tires on those vehicles 100 (not limited to the same) which may show little to no change in response even with a much deflated tire. The present invention aims to provide a low-fidelity estimation of tire pressure abnormality. The present invention provides a safety/maintenance feature which estimates tire pressure level in each tire of the vehicle 100 (such as the motorcycle) without using additional sensors.

[0022] According to the present invention, the apparatus 120 and method are designed on the fact that once a tire is punctured it starts losing pressure, which reduces the effective tire radius. As the tire radius falls, that specific tire speeds up relative to the other tire in a consistent manner unlike the relative wheel speed difference caused by other causes such as steering. The present invention is able to do the computation necessary to detect said consistent relative wheel speed difference in real-time in an efficient manner.

[0023] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

Claims

We claim:

1. An apparatus ( 120) for tire pres sure abnormality detection in a vehicle (100), said apparatus (120) comprises at least one controller configured to, receive input signals from wheel speed sensors (102, 104) of a front wheel and a rear wheel, while said vehicle (100) is in motion, calculate parameters comprising vehicle speed, acceleration, and wheel speed difference between said front wheel and said rear wheel based on said received input signals, and check associated entry conditions, characterized in that calculate a long moving average and a short moving average of said wheel speed differences when said entry conditions are satisfied, detect tire pressure abnormality based on divergence between said long moving average and short moving average.

2. The apparatus (120) as claimed in claim 1, wherein for detection of said tire pressure abnormality, said controller configured to, check if said divergence exceeds a threshold divergence value, and while said divergence exceeds said threshold divergence value, calculate a deviation between a saturated wheel speed difference value with a calibratable base value after elapse of an estimated time for reconvergence, and confirm detection of said tire pressure abnormality when said deviation is more than threshold deviation.

3. The apparatus (120) as claimed in claim 1 is at least one selected from a group comprising an internal device comprising an Electronic Control Unit (ECU) (110) of said vehicle (100), and an external device comprising at least one of a cloud based device (108) and a communication device (112), wherein said ECU (110) is at least one of an Engine Management System (EMS) controller, a Tire Pressure Monitoring System (TPMS) controller, a Telematics Control Unit (TCU) controller, an Anti-lock Braking System (ABS) controller, an Electronic Stability Program (ESP) controller and a combination thereof. The apparatus (120) as claimed in claim 3, wherein when said apparatus (120) is said external device, said external device is configured to receive only those said input signals from said ECU (110) which satisfies said entry conditions, said inputs signals are received until at least a minimum required datasets are met. The apparatus (120) as claimed in claim 1, wherein said tire pressure abnormality relates to at least one of a puncture and a leakage, wherein said puncture is a slow puncture. A method for detecting tire pressure abnormality in a vehicle (100), said method comprises the steps of, receiving input signals from wheel speed sensors (102, 104) of a front wheel and a rear wheel, while said vehicle (100) is in motion, calculating parameters comprising vehicle speed, acceleration, and wheel speed difference between said front wheel and said rear wheel based on said received input signals, and checking associated entry conditions, characterized by calculating a long moving average and a short moving average of said wheel speed differences when said entry conditions are satisfied, detecting tire pressure abnormality based on divergence between said long moving average and short moving average. The method as claimed in claim 6, for detecting said tire pressure abnormality, said method comprises, checking if said divergence exceeds a threshold divergence value, and while said divergence exceeds said threshold divergence value, calculating a deviation between a saturated wheel speed difference value with a calibratable base value after elapse of an estimated time for reconvergence, and confirming detection of said tire pressure abnormality when said deviation is more than threshold deviation. The method as claimed in claim 6 is at least one selected from a group comprising an internal device comprising an Electronic Control Unit (ECU) (110) of said vehicle (100), and an external device comprising at least one of a cloud based device (108) and a communication device (112), wherein said ECU (110) is at least one of an Engine Management System (EMS) controller, a Tire Pressure Monitoring System (TPMS) controller, a Telematics Control Unit (TCU) controller, an Anti-lock Braking System (ABS) controller, an Electronic Stability Program (ESP) controller and a combination thereof. The method as claimed in claim 8, wherein when said apparatus (120) is said external device, said external device is configured to receive only those said input signals from said ECU (110) which satisfies said entry conditions, said inputs signals are received until at least a minimum required datasets are met. The method as claimed in claim 6, wherein said tire pressure abnormality relates to at least one of a puncture and a leakage, wherein said puncture is a slow puncture.