Description: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 to determine tire pressure abnormality 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] Further, an indirect Tire Pressure Monitoring System (TPMS) method involves comparing tire speeds and consistently checking abnormal difference, due to deflated tires rotating faster. But this detection only works in case of lopsided deflation as any other possibility will act similar to the healthy state (w.r.t tire speeds). Without Global Positioning System (GPS) there is no way to measure accurately the true speed of the vehicle, thus making it impossible to detect both tires deflated case. The indirect TPMS rely on evaluating wheel speed difference to estimate relative pressure loss in tires. Due to this relative method, all combinations in which both tires are deflated the method fails to detect the deflation.

[0004] 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 for judging decrease in internal pressure. A decrease in air-pressure in a two-wheeled vehicle can be judged so as to enable safe driving.

Brief description of the accompanying drawings:
[0005] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0006] Fig. 1 illustrates a block diagram of an apparatus to determine tire pressure abnormality in a vehicle, according to an embodiment of the present invention, and
[0007] Fig. 2 illustrates a method determining tire pressure abnormality in a vehicle, according to the present invention.

Detailed description of the embodiments:
[0008] Fig. 1 illustrates a block diagram of an apparatus to determine tire pressure abnormality in a vehicle, according to an embodiment of the present invention. The apparatus 120 comprises at least one controller configured to, receive and measure wheel speeds of a front wheel and a rear wheel using respective wheel speed sensors 102, 104, as input signals while the vehicle 100 is in motion. The controller computes rate of change of vehicle speed using at least one of the wheel speed sensors 102, 104 or by estimating the vehicle speed using engine speed and the gear ratio or using an accelerometer, and detects at least one operating zone selected from an acceleration zone and a deceleration zone, characterized in that, the controller calculates a metric followed by average of the metric for the detected zone. The metric is calculated using the wheel speed for the front wheel and the rear wheel. The controller compares the averaged metric with a predetermined range and determines the tire pressure abnormality in at least one of the front wheel and the rear wheel. The controller is able to determine abnormality by using the longitudinal dynamics of the vehicle 100.

[0009] In accordance to an embodiment of the present invention, the metric is a ratio of wheel speed of front wheel and the rear wheel (or rear wheel and front wheel). Alternatively, the metric is difference of the wheel speed of the front wheel and the rear wheel (or rear wheel and front wheel).

[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, Anti-lock Braking System (ABS) ECU 110, a Body Control Unit (BCU), a Human-Machine Interface (HMI) cluster unit, other vehicular controllers and a combination thereof. The communication device 112 corresponds to electronic computing devices such as smartphone, wearable electronics such as smart watch, intelligent HMI cluster (or connected cluster) in the vehicle 100 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 usable/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. 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 in following paragraphs.

[0012] The apparatus 120 which is at least one internal device and the external, 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 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, identify all time instances at which the stable operating zone of the vehicle 100 is present, extract input signals of wheel speeds of only those which fall under the stable operating zone. Thus, in general when the apparatus 120 is the external device, the external device is configured to receive only those input signals from the ECU 110 which falls under the at least one operating zone. The input signals are received until at least a minimum required datasets are met. The datasets refer to those set of input signals which contains the wheel speed for each wheel at those instances when the at least one operating zone is detected.

[0014] The cloud based device 108 then compares the averaged metric with a predetermined range and determines tire pressure abnormality in any one of the front wheel and the rear wheel. The cloud based device 108 then transmits the results back to the ECU 110 of the vehicle 100, where the tire pressure abnormality is indicated to the driver. In an embodiment, the abnormality is indicated to the driver of the vehicle 100 by an output means 114 through at least one selected from an audio signal, a visual signal (such as blinking pattern or colors), a display (such as instrument cluster), a haptic signal and a combination thereof. The output means 114 is part of at least one of the vehicle 100 and the communication device 112 of the driver.

[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 process 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. The data transmission between cloud computing device 108 and the communication device 112 is also possible.

[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) on 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 which comes under the at least one operating zone. The inputs signals are received for at least a minimum required datasets are met, such as 1500 datasets (less or more can be used based on specific requirements) of the wheel speeds for each of the front wheel and the rear wheel at the same time instant which denotes the at least one operating zone. Further, the at least one operating zone may be distributed during the drive of the vehicle 100 and need not be continuous. 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 time instances at which the operating zone is present, and sends only necessary inputs signals (datasets) to the cloud based device 108. In an alternate embodiment, instead of wheel speeds, only wheel speed differences are sent 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 two-wheeler such as scooter, motorcycle, a three-wheeler such as autorickshaw, a four wheeler such as cars, and multi-wheel vehicles 100.

[0018] In accordance to an embodiment of the present invention, there are different manners in which the at least one operating zone is determined. In an embodiment, at least one of the wheel speed sensors 102, 104 is directly used to determine the vehicle speed and thereafter the operating zone. In another embodiment, the vehicle speed is estimated from engine speed (using an engine speed sensor) and current gear position and optionally radius of the wheel. In yet another embodiment, an existing accelerometer of the vehicle 100 or an Inertial Measurement Unit (IMU) or accelerometer of the communication device 112 docked in the vehicle 100 is usable. The communication device 112 must be in communication with the ECU 110 of the vehicle 100.

[0019] Fig. 2 illustrates a method determining tire pressure abnormality in a 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 computing rate of change of vehicle speed using at least one of the wheel speed sensors 102, 104 or engine speed and gear ratio or accelerometer, and detecting the at least one operating zone. The method is characterized by a step 206 which comprises, calculating the metric followed by the cumulative average value metric while and whenever the vehicle 100 is detected to be in the one of the at least one operating zone. The metric is calculated using the wheel speeds of the front wheel and the rear wheel. A step 208 comprises comparing the averaged metric with the predetermined range and determining tire pressure abnormality in at least one of the front wheel and the rear wheel. The metric is any one of the ratio of wheel speed of front wheel and rear wheel (or rear wheel and front wheel) and a difference of wheel speed of front wheel and rear wheel (or rear wheel and front wheel). A step 210 comprises indicating the abnormality to the driver of the vehicle 100 by the output means 114 through at least one selected from an audio signal, a visual signal and haptic signal. The output means 114 is part on any one of the vehicle 100 and the communication device 112 of the driver. No indication or alert is provided in case of no abnormality. The method is able to determine abnormality by using the longitudinal dynamics of the vehicle 100. The method is executed by the apparatus 120 as described above.

[0020] The method is executed by at least one apparatus 120 selected from a group comprising the internal device such as the 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) ECU 110, the Body Control Unit (BCU), the Human-Machine Interface (HMI) cluster unit, other vehicular controllers, and the combination thereof.

[0021] The method when executed by the external device, comprises receiving, by the external device, only those input signals from the ECU 110 which comes under the at least one operating zone. The inputs signals are received until at least a minimum required datasets are met.

[0022] In accordance to an embodiment of the present invention, an indirect Tire Pressure Monitoring Systems (TPMS) for two-wheelers with wheel speed data using longitudinal dynamics is provided. Specifically, a method which evaluates individual tire pressure levels based on longitudinal dynamics of a two-wheeler is provided. The present invention aims to provide a low-fidelity estimation of tire pressure abnormality based on at least one operating zone of the vehicle 100. 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. In the present invention, the apparatus and the method evaluates the wheel speed difference during longitudinal transients (acceleration and braking zones). During said transients, load transfer applies lopsided loading on each wheel. At such states, even if both tires are similar states (both are inflated/deflated) they respond differently when both are deflated compared to both being inflated.

[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) to determine tire pressure abnormality in a vehicle (100), said apparatus (120) comprises at least one controller (110) configured to:
receive and measure wheel speeds of a front wheel and a rear wheel using respective wheel speed sensors (102, 104) as input signals while said vehicle (100) is in motion, characterized in that
compute rate of change of vehicle speed and detect at least one operating zone selected from an acceleration zone and a deceleration zone;
calculate a metric followed by an average of said metric for said detected zone, said metric is calculated using said wheel speed for said front wheel and said rear wheel, and
compare said averaged metric with a predetermined range and determine tire pressure abnormality in at least one of said front wheel and said rear wheel.

2. The apparatus (120) as claimed in claim 1, wherein said metric is any one of a ratio of wheel speed of front wheel and rear wheel, and a difference of wheel speed of front wheel and rear wheel.

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, and a combination thereof.

4. 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 falls under said at least one operating zone, said inputs signals are received until at least a minimum required datasets are met.

5. The apparatus (120) as claimed in claim 1, wherein said abnormality is indicated to a driver of said vehicle (100) by an output means (114) through at least one selected from an audio signal, a visual signal and haptic signal, wherein said output means (114) is part on at least one of said vehicle (100) and a communication device (112) of said driver.

6. A method to determine tire pressure abnormality in a vehicle (100), said method comprises the steps of:
measuring wheel speed of a front wheel and a rear wheel, using respective wheel speed sensors (102, 104), and deriving vehicle speed, characterized by,
computing rate of change of vehicle speed and comparing with a threshold range to identify at least one operating zone selected from an acceleration zone and a deceleration zone;
calculating a metric followed by an average of said metric for said identified zone, said metric is calculated using said wheel speed for said front wheel and said rear wheel, and
comparing said averaged metric with a predetermined range and determining tire pressure abnormality in at least one of said front wheel and said rear wheel.

7. The method as claimed in claim 6, wherein said metric is any one of a ratio of wheel speed of front wheel and rear wheel, and a difference of wheel speed of front wheel and rear wheel.

8. The method as claimed in claim 6, wherein said method is executed by at least one apparatus (120) 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, and a combination thereof.

9. The method as claimed in claim 9 when executed by said external device, comprises receiving, by said external device, only those said input signals from said ECU (110) which comes under said at least one operating zone, said inputs signals are received until at least a minimum required datasets are met.

10. The method as claimed in claim 6, wherein said indicating said abnormality to a driver of said vehicle (100) by an output means (114) through at least one selected from an audio signal, a visual signal and haptic signal, wherein said output means (114) is part on any one of said vehicle (100) and a communication device (112) of said driver.