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 a device for Tire Pressure Monitoring System (TPMS) for a two-wheeler vehicle and method thereof.

Background of the invention:
[0002] In the current state of the art, a Tire Pressure Monitoring System (TPMS) for two wheelers require two pressure sensors mounted on each wheel, i.e. a front wheel and a rear wheel. The sensors transmit the pressure data via Bluetooth or Radio Frequency (RF) to a receiver module which could be a separate unit or integrate into any existing control unit of the two wheeler. But the cost for two sensors current in the market is high. But this cost makes such a system prohibitively expensive for mass market adoption. Hence, there is a need for a cost effective and technical solution.

[0003] A patent literature 202211027784 discloses a tyre pressure indicator in two-wheeler. The invention presents a sensor based device attached to the nozzle of the tyres (both front and rear); which will detect whenever the air pressure falls below the desired level i.e., standardized pressure. If the pressure is found to be below the threshold value, the system will reflect the data in the vehicle dashboard also a notification for the same is send to the mobile connected to the vehicle. A mobile app for the same is to be developed which is connected to the vehicle; and app will update the critical pressure values and provide the required information in the form of notification.

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 a device for Tire Pressure Monitoring System (TPMS) for a two-wheeler vehicle, according to an embodiment of the present invention;
[0006] Fig. 2 illustrates graphs related to tire pressure of wheels of the vehicle, according to an embodiment of the present invention, and
[0007] Fig. 3 illustrates a method for determining tire pressure in a two-wheeler vehicle, according to the present invention.

Detailed description of the embodiments:
[0008] Fig. 1 illustrates a block diagram of a device for Tire Pressure Monitoring System (TPMS) for a two-wheeler vehicle, according to an embodiment of the present invention. The device 120 comprises at least one controller configured to determine a front wheel speed and a rear wheel speed using respective wheel speed determining means. The controller also configured to receive a tire pressure signal from a tire pressure sensor 106 mounted to a first wheel (or first wheel tire), characterized in that, the controller calculates a value selected from any one of a ratio and difference of the front wheel speed and said rear wheel speed, and determines a tire pressure of a second wheel (or second wheel tire) using the calculated value and the received tire pressure signal of the first wheel. The tire pressure sensor 106 is mounted only to the first wheel. Just for clarity, a tire fixed to the first wheel is referred to as the first wheel and a tire fixed to the second wheel is referred to as the second wheel tire. Thus, the first wheel or front wheel is interchangeably usable with first wheel tire or front wheel tire. Similarly, the second wheel or rear wheel is interchangeably usable with second wheel tire or rear wheel tire.

[0009] According to the present invention, the ratio is either a direct ratio or normalized ratio. The normalized ratio corresponds to ratio of direct wheel difference and addition of wheel speeds, explained later. The direct ratio corresponds to front wheel speed/rear wheel speed or rear wheel speed/front wheel speed.

[0010] According to an embodiment of the present invention, the tire pressure of the second wheel is determined by a co-relation table/map/model based on the calculated value and the received tire pressure. The co-relation table/map/model is stored in a memory element 122 of the controller. The controller 110 processes the determined tire pressure through a hysteresis module to provide stable output.

[0011] According to the present invention, the device 120 makes use of at least one optional speed filtration/smoothening modules for the wheel speed either estimated or measured. The filtration/smoothening modules removes the noise or spikes in the signal. In addition, the hysteresis module is usable right after determining the tire pressure of the second wheel. The hysteresis block avoids any incorrect estimation.

[0012] According to an embodiment of the present invention, the first wheel is any one of a front wheel 116 and a rear wheel 118, and the second wheel is other of the front wheel 116 and the rear wheel 118. Hence, as per the present invention, the tire pressure sensor 106 is mounted to either the front wheel 116 or the rear wheel 118. If the tire pressure sensor 106 is mounted to the first wheel 116, then the tire pressure of the rear wheel 118 is estimated. Similarly, if the tire pressure sensor 106 is mounted to the rear wheel 118, then the tire pressure of the front wheel 116 is estimated.

[0013] According to an embodiment of the present invention, the wheel speed determining means is at least one selected from a group comprising a wheel speed sensor 102, 104 and a module to calculate wheel speed using gear ratio and current engine speed. Thus, a combination of one wheel speed sensor 102, 104 in the first wheel and the module in the second wheel is possible to be used. The gear ratio in the module is determinable by either a sensor or estimated/calculated using ratio of wheel speed and engine speed. The controller 110 also comprises the at least one filtration/smoothening modules to filter/smoothen the determined wheel speed.

[0014] According to the present invention, the device 120 is at least one of an internal device and an external device. The internal device is at least one Electronic Control Unit (ECU) 110 selected from a group comprising 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, a Vehicle Instrument Cluster (VIC) controller, and a combination thereof. The external device is at least one of a cloud based device 108 and a communication device 112. The external device is connected through a Telematic Control Unit (TCU) of the vehicle 100 through at least one a wired and wireless means known in the art. 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.

[0015] According to an embodiment of the present invention, the device 120 is implementable in different manners or scenarios. In a first scenario, the device 120 is just the ECU 110 of the vehicle 100. Thus, the tire pressure of the second wheel is determined and then indicated to the driver directly by the ECU 110 of the vehicle 100. In a second scenario, the device 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 or VIC through wired or wireless means as known in the art. The input signals are the wheel speeds of the front wheel 116 and the rear wheel 118, either estimated or measured, and the tire pressure of the first wheel. In a third scenario, the device 120 is combination of the internal device and external device, i.e. the device 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.

[0016] The device 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 122 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 122 of the device 120 is prestored with map, table. Model, modules, logics, instructions, programs, applications, 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 device 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.

[0017] In accordance to an embodiment of the present invention and as per the second scenario, the device 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 device 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 device 120 is the cloud based device 108, the cloud based device 108 receives all the tire pressure monitoring related signals (input signals) and the wheel speed 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, the tire pressure for a front wheel, and then calculate tire pressure of the second wheel by using a co-relation table/map/model stored in the controller. The co-relation table/map is referred to using the measured tire pressure of the front wheel and the determined value. The cloud based device 108 then transmits the results back to the ECU 110 of the vehicle 100, where the tire pressure of the second wheel 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.

[0018] Similarly, when the device 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, Universal Serial Bus (USB) 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.

[0019] In accordance to an embodiment of the present invention and as per the third scenario, the device 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 device 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 and the tire pressure for the first 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 along with the tire pressure of the first wheel. For example, consider the device 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 the tire pressure signal for the first wheel) 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 device 120 indicates the tire pressure of the second wheel at any one of during a driving of the vehicle 100 and after end of the driving.

[0020] 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. The determined tire pressure may also indicate an abnormality such as a puncture and a leakage. Further, the vehicle 100 is either internal combustion engine based or electric vehicle or hybrid vehicle.

[0021] According to the present invention, a working of the device 120 is explained. Consider a motorcycle is used as the vehicle 100. The front wheel 116 is fixed with at least one tire pressure sensor 106 as part of the TPMS. The wheel speed sensor 102, 104 or means of computing the wheel speed for the front wheel 116 and the rear wheel 118 or combination are provided. When the motorcycle is driven, the wheel speed of the first wheel and the second wheel are continuously (or as per pre-determined samples) monitored by the device 120. The device 120 calculates the value for each collected data and co-relates to corresponding rear wheel tire pressure using the first wheel tire pressure measured using the tire pressure sensor 106.

[0022] According to the present invention, a single tire pressure sensor 106 based TPMS setup is disclosed. The setup comprises at least one tire pressure sensor 106 in either front tire or the rear tire is positioned/installed. The wheel speed sensor 102 in front wheel or a means of computing front wheel speed is provided. Similarly, the wheel speed sensor 104 in the rear wheel or the means of computing the rear wheel speed is provided. Alternatively, a combination of wheel speed sensor 102, 104 in first wheel and means for computing the wheel speed of the second wheel is provided. The means for the computing the wheel speed is by using information on gear (either sensor based or computed) and engine speed to compute rear wheel speed in case of a positive locked drive system such as chain drive. Further, the controller is capable of receiving signals from Bluetooth™ based tire pressure sensor 106. Alternatively, a Radio Frequency (RF) based tire pressure sensor or any other communication type, 106 is also usable. The controller (same or different from the one above) hosts the algorithm/software to compute the other tire pressure. Further, the working principle is use of co-relation between tire pressure ratio and normalized wheel speed ratio/difference in wheels of the vehicle 100, such as the two-wheeler vehicle 100. A deflated tire (for example of rear wheel 118) has a lesser rolling radius (R2) due to which maintaining the same vehicle speed, it will have to rotate faster than the fully inflated tire (R1) (for example of front wheel 116). Hence if there is a tire that if deflated more in comparison to the other, the tire pressure of the other tire is estimated using the wheel speed ratios of the front and rear wheel speeds and measured tire pressure using the co-relation table/map/model.

[0023] Fig. 2 illustrates graphs related to tire pressure of wheels of the vehicle, according to an embodiment of the present invention. A first graph 200 shows plot of the value, specifically the difference between the front wheel speed and the rear wheel speed. The wheel speed difference is plotted in Y-axis against time in X-axis. Similarly, a second graph 210 shows a plot of a rear tire pressure and wheel speed ratio against front tire pressure. The front tire pressure is shown in X-axis and the rear tire pressure, and the normalized wheel speed ratio are shown in left and right side of the Y-axis, respectively. The normalized wheel speed ratio is defined by ratio of difference of front wheel speed (VF) and rear wheel speed (VR) and addition of front wheel speed (VF) and rear wheel speed (VR), i.e. (VF - VR)/( VF + VR).

[0024] In the first graph 200, a first curve 202 represents the plot of wheel speed difference when the front tire pressure is 70% of the rated tire pressure and the rear tire pressure is 100% of the rated tire pressure. A second curve 204 when both the plot of wheel speed difference with the first tire pressure and the second tire pressure are 70% of rated tire pressure. The. The third curve 206 represents a plot where both the front tire pressure and the rear tire pressure are at 100% of the rated pressure. A fourth curve represents the plot of the wheel speed differences when the front tire pressure is 100% of the rated pressure and the rear tire pressure is 70% of the rated pressure. With the use of present invention where the tire pressure sensor 106 is used in one of the first wheel and the second wheel, the controller is able to detect the tire pressure deflation in scenarios related to the first curve 202 through fourth curve 208, which otherwise would have been possible only in the first curve 202 and the fourth curve 208 and not in the second curve 204 and the third curve 206. Thus, the single tire pressure sensor 106 based concept has advantages. To identify which wheel is having the low pressure in case of second curve 204 and the third curve 206, since one of the tire pressure from the tire pressure sensor 106 is known, the tire pressure of the second wheel is obtained.

[0025] The second graph 210 shows that for each value of front pressure sensor value, there is a unique value for rear tire pressure from the normalized wheel speed ratios. In an example, a plot 212 represents the pressure of the rear wheel tire. The other plots represents the wheel speed ratio. By using the two plots, the rear wheel tire pressure is determined.

[0026] Fig. 3 illustrates a method for determining tire pressure in a two-wheeler vehicle, according to the present invention. The vehicle 100 comprises the Tire Pressure Monitoring System (TPMS) for the first wheel. The method comprises plurality of steps of which a step 302 comprises determining the front wheel speed and a rear wheel speed using respective wheel speed determining means. A step 304 comprises receiving the tire pressure signal from the tire pressure sensor 106 mounted to the first wheel. The method is characterized by a step 306 which comprises calculating the value selected from any one of the ratio and difference of the front wheel speed and the rear wheel speed. A step 308 comprises determining the tire pressure of the second wheel using the value and the received tire pressure of the first wheel.

[0027] The step 308 of determining tire pressure of the second wheel is done using the co-relation table/map/model of the value and the received tire pressure stored in the memory element 122. The step 308 optionally comprises a step of processing the determined tire pressure through the hysteresis module for the stable output. The first wheel is any one of the front wheel 116 and the rear wheel 118, and the second wheel is other of the front wheel 116 and the rear wheel 118. The wheel speed determining means is at least one selected from the group comprising the wheel speed sensor 102, 104 and the module to calculate wheel speed using gear ratio and current engine speed. The step 302 optionally comprises a sub-step of filtering the determined wheel speed using at least one speed filtration/smoothening modules.

[0028] The method is executed by the controller of the device 120. The device 120 at least one of the internal device and the external device. The internal device is at least one Electronic Control Unit (ECU) 110 selected from the group comprising 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, the Vehicle Instrument Cluster (VIC) controller, and the combination thereof. The external device is at least one of the cloud based device 108 and the communication device 112. The external device is connected through any of the Telematic Control Unit (TCU) and the Vehicle Instrument Cluster (VIC) controller of the vehicle 100 through at least one the wired and wireless means as known in the art.

[0029] According to the present invention, a tire pressure monitoring solution using only single tire pressure sensor 106 is disclosed. In other words, the current solution proposes the device and the method by which only one tire pressure sensor 106 is used in any one of the tire to compute the tire pressure in the second wheel/tire by establishing a correlation between known pressure and individual wheel speeds. Thus, the cost of second tire pressure sensor is eliminated, thereby making the TPMS very cost effective. Further, wheel speed sensor 102, 104 is replaceable by alternate means of wheel speed computation such as gear ratio and engine speed based rear wheel speed computation. Furthermore, instead of normalized wheel speed ratio, normalized wheel speed difference is also usable. Only the calibration in the co-relation table is changed between using the wheel speed ratio and the wheel speed differences. The speed filtration/smoothening and hysteresis blocks are not mandatory and only adds to the robustness of the prediction of the tire pressure determination of the second wheel/tire. Additionally, further data filtration can be done on the basis of one or more of parameters such as vehicle speed, vehicle acceleration, front wheel slips, rear wheel slips, vehicle torque etc.

[0030] 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. A device (120) for Tire Pressure Monitoring System (TPMS) for a two-wheeler vehicle (100), said device comprises a controller configured to,
determine a front wheel speed and a rear wheel speed using respective wheel speed determining means;
receive a tire pressure signal from a tire pressure sensor (106) mounted to a first wheel, characterized in that,
calculate a value selected from any one of a ratio and difference of said front wheel speed and said rear wheel speed, and
determine a tire pressure of a second wheel using said calculated value and said received tire pressure of said first wheel measured by using said tire pressure sensor (106), wherein said tire pressure sensor (106) is mounted only to said first wheel.

2. The device (120) as claimed in claim 1, wherein said tire pressure of said second wheel is determined by a co-relation table/map based on said value and said received tire pressure, said co-relation table/map/model is stored in a memory element (122) of said controller, wherein said determined tire pressure is optionally processed through a hysteresis module for a stable output.

3. The device (120) as claimed in claim 1, wherein said first wheel is any one of a front wheel (116) and a rear wheel (118), and said second wheel is other of said front wheel (116) and said rear wheel (118).

4. The device (120) as claimed in claim 1, wherein said wheel speed determining means is at least one selected from a group comprising a wheel speed sensor (102, 104) and a module to calculate wheel speed using gear ratio and current engine speed, wherein said controller optionally filters said determined speed using at least one speed filtration/smoothening modules.

5. The device (120) as claimed in claim 1 is at least one of an internal device and an external device, wherein said internal device is at least one Electronic Control Unit (ECU) (110) selected from a group comprising 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, Vehicle Instrument Cluster (VCU) controller and a combination thereof, and said external device is at least one of a cloud (108), and a communication device (112), wherein said external device is connected through any one of said Telematic Control Unit (TCU) and said Vehicle Instrument Cluster (VCU) controller of said vehicle (100) through at least one a wired and wireless means.

6. A method for determining tire pressure in a two-wheeler vehicle (100), said vehicle (100) comprises a Tire Pressure Monitoring System (TPMS), said method comprising the steps of:
determining a front wheel speed and a rear wheel speed using respective wheel speed determining means;
receiving a tire pressure signal from a tire pressure sensor (106) mounted to a first wheel, characterized by,
calculating a value selected from any one of a ratio and difference of said front wheel speed and said rear wheel speed, and
determining a tire pressure of a second wheel based on said value and said received tire pressure of said first wheel, wherein said tire pressure sensor (106) is mounted only to said first wheel.

7. The method as claimed in claim 6, wherein said tire pressure of said second wheel is determined using a co-relation table/map based on said value and said determined tire pressure, said co-relation table/map/model is stored in a memory element (108), wherein said method comprises optionally processing said determined tire pressure through a hysteresis module for a stable output.

8. The method as claimed in claim 6, wherein said first wheel is any one of a front wheel (116) and a rear wheel (118), and said second wheel is other of said front wheel (116) and said rear wheel (118).

9. The method as claimed in claim 6, wherein said wheel speed determining means is at least one selected from a group comprising a wheel speed sensor (102, 104) and a module to calculate wheel speed using gear ratio and current engine speed, wherein said method comprises optionally filtering said determined speed using at least one speed filtration/smoothening modules.

10. The method as claimed in claim 6 is executed by a controller of a device (120), said device (120) at least one of an internal device and an external device, wherein said internal device is at least one Electronic Control Unit (ECU) (110) selected from a group comprising 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, Vehicle Instrument Cluster (VIC) controller and a combination thereof, and said external device is at least one of a cloud based device (108), and a communication device (112), wherein said external device is connected through any one of said Telematic Control Unit (TCU) or said Vehicle Instrument Cluster (VIC) controller of said vehicle (100) through at least one a wired and wireless means.