WO2022113118A1

WO2022113118A1 - A tire pressure monitoring system

Info

Publication number: WO2022113118A1
Application number: PCT/IN2021/051113
Authority: WO
Inventors: Subramoniam C; Kalpana VALAVANUR UMASANKAR; Ramakrishna Pandian KRISHNA KUMAR; Chippa SUNIL KUMAR; Mansoor B; KR Roy HILLOL
Original assignee: Tvs Motor Company Limited
Priority date: 2020-11-30
Filing date: 2021-11-28
Publication date: 2022-06-02

Abstract

A system for monitoring tyre pressure 100 in a vehicle comprises of a control system 101, and a telematics system 102. The control system 101 includes a power control system 101(aa) and a vehicle control unit 101(ab). The control system 101 being configured to calculate a speed of a drive unit (not shown) of the vehicle, where an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit. The telematics system 102 being configured to calculate a real time GPS speed of the vehicle, where a real time GPS distance covered by the vehicle being calculated based on said real time GPS speed. The control system 101 being configured to calculate a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance.

Description

A TYRE PRESSURE MONITORING SYSTEM

TECHNICAL FIELD

[0001] The present subject matter relates generally to a vehicle. More particularly but not exclusively the present subject matter relates to a tyre pressure monitoring system and method thereof.

BACKGROUND

[0002] With the advancement in technology, different variants for different user segments are being developed by the automobile manufactures. For example, two wheeler industry is flooded with vehicles with unique aesthetic features, different power outputs, different load carrying requirements, and the like. Various types of traction mechanisms for the two-wheeled vehicles are also developed. For example, hybrid electric two-wheeled vehicles have two traction mechanisms involved, which includes an internal combustion engine-based traction mechanism, and an electric motor-based traction mechanism. The electric two-wheeled vehicles have only electric motor-based traction mechanism.

[0003] Generally, the electric motor for these vehicles is mounted on a rim/hub (generally known as hub motor) of a rear wheel such that the power is directly transferred to the rear wheel to facilitate efficient traction of the vehicle. Hub motor provides compactness and simplicity which is an important feature in an electric vehicle. The hub motor is integrated with the wheel assembly where the stator portion of the motor is mounted on a swing arm while the wheel rim is welded to the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The details are described with reference to an embodiment implemented in a vehicle along with the accompanying figures. The same numbers are used throughout the drawings to reference similar features and components.

[0005] Figure 1 exemplarily illustrates a block diagram for a tyre pressure monitoring system. [0006] Figure 2(a) and 2(b) exemplarily illustrates a flow chart for calculating the tyre pressure.

[0007] Figure 3 exemplarily illustrates an elaborated flow chart for calculating the tyre pressure.

[0008] Figure 4 exemplarily illustrates a flow chart for calculating acceleration of the vehicle.

[0009] Figure 5 exemplarily illustrates a flowchart for calculating roll angle and pitch angle of the vehicle.

DETAILED DESCRIPTION

[0001] As described in earlier paragraphs, in a conventional internal combustion engine, and the vehicles having a hub motor, the hub motor and the rim of the rear wheel are susceptible to damage if it passes through any obstacle like pot holes while having low tyre pressure or punctured tyre of the rear wheel. Specially, in high power vehicles chances of such problem are more as high-power motor runs at a high speed and at such high speed and low tyre pressure, hitting an obstacle like pothole may cause more damage to rim of the rear wheel. When the vehicle moves over a pot hole, the wheel rim bends or breaks if the tyre pressure is lesser than critical limit. In such cases, there is a possibility that rim of the rear wheel may bend causing degradation in stability and functionality of the rear wheel, also this may raise safety concerns for the rider. As rim breakage or bend in a traction motor is irreparable, the traction motor needs to be replaced in such cases which incurs huge cost to the user. In addition to this, Low tyre pressure affects the vehicle’s energy consumption and leads to poor handling and braking. Also, life span of the tyre reduces.

[0002] Therefore, a system and method are required in which the rider is aware of the real-time tyre pressure, so that a timely maintenance/precautionary decision can be taken and a damage to the rim can be avoided as well as ensure safety of the user of the vehicle. Rider needs to be pro-actively informed that the tyre should be changed or the vehicle is running with inadequate tyre pressure, which should be maintained within suggested limits.

[0003] Conventionally, different types of direct Tyre Pressure Monitoring Systems (TPMS) are readily available in market that can be simply fitted with the wheel and can be wirelessly connected to a mobile phone of a user, through a real time tyre- pressure monitoring. Such TPMS include one or more tyre pressure sensors and other parts, which are to be installed in the wheel which results in increase in cost of the vehicle for the user, adds complexity to the system, and also adds to the difficulty in maintenance throughout the life of the vehicle. If the user is not carrying the mobile phone then the indication for the tyre pressure is not instantly known to the user. Also, while riding the two wheeled vehicle it may not be possible for the rider to regularly check for the warnings available on the mobile phone. Hence, in case of sudden drop of the tyre pressure, it may not be registered by the rider, which may lead to serious damage of rim of the wheel if driving in rough road conditions as well as potential safety risk if riding continued with low pressure conditions. The safety risk often becomes precarious especially when riding with pillion or load where the chances of sudden puncture, at reasonable driving speeds, is high.

[0004] Additionally, there are some indirect tyre pressure monitoring methods available that utilize the vehicle’s Anti-Lock Braking System’s wheel Speed sensors. When the tyre pressure is low in any one of the wheels, the wheel with lower pressure rolls at a different wheel speed than the speed at which it would have rolled if operating at normal tyre pressure. The difference in wheel speeds is sensed by a vehicle control unit to detect the reduction in tyre pressure. In this, the system requires a minimum of two, wheel speed sensors for its function and also low tyre pressure goes undetected if both the tyres deflate by equal amounts. Such indirect TPMS are relative by nature and cannot display or measure the absolute pressure values in real time. While prior arts have attempted to address some of the above problems, they do it albeit at a trade-off with some of the above cited aspects and functionalities, which leaves known solutions undesirable. [0005] Therefore, there exists a need for a mechanism that can provide indirect tyre pressure monitoring system for monitoring the tyre pressures of individual tyres which alerts the user at different levels of tyre pressure, without adding additional parts cost and complexity, is durable, is easy to handle, gives good mileage, and is safe to operate. So, there is a need to cater to the various requirements of tyre pressure measuring system while overcoming all above problems as well as other problems of known art.

[0006] An objective of the present subject matter is to provide a system and a method for monitoring tyre pressure in a vehicle without using any pressure sensors preventing additional parts cost and complexity, the proposed design does not depend on the difference in wheel speeds as a means to detect the reduction in tyre pressure, and the reduction in tyre pressure can be detected even if all the wheels deflate by equal amounts. The present subject is applicable to any type of vehicle, with required changes and without deviating from the scope of invention. As per the present invention, a system for monitoring a tyre pressure in a vehicle comprises a control system being configured to calculate a speed of a drive unit of the vehicle, where an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit; and a telematics system being configured to calculate a real time GPS speed of the vehicle. The real time GPS distance covered by the vehicle being calculated based on said real time GPS speed. The control system being configured to calculate a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance.

[0007] As per an aspect of the present subject matter, the control system includes one or more of a power control unit and a vehicle control unit. As per an embodiment of the present invention, the power control unit can be an IC engine control unit or a motor control unit while a vehicle control unit can be any other control unit like a EFI control unit, a brake system control unit, a BMS control unit or the like.

[0008] As per an aspect of the present subject matter, the control system comprising the power control unit configured to communicate with the vehicle control unit, a sensor is configured to obtain speed of the drive unit of the vehicle to calculate the ideal distance of the vehicle; and a temperature sensor configured to obtain a coil temperature of the drive unit for determining the tyre pressure.

[0009] As per another aspect of the present subject matter, the vehicle control unit being configured to communicate with said power control system and said telematics unit to store and process received data from said power control unit and said telematics unit. The vehicle control unit being configured to indicate a tyre pressure to a user of the vehicle in a current power cycle and in a next power cycle, said indication being through one or more of an audio and visual indication on a display device. The vehicle control unit being configured to decide a running state of said vehicle.

[00010] As per another aspect of the present subject matter, the vehicle control unit immobilizes the vehicle after a predetermined number of low tyre pressure indications.

[00011] As per another aspect of the present subject matter, the telematics system includes a telematics unit, a GPS device, an accelerometer, and a modem connected to a data server. The GPS device tracks the vehicle in terms of a latitude and a longitude to enable the telematics unit to calculate the real time GPS distance. The accelerometer calculates an acceleration value due to gravity along a 3-axis (X, Y, Z) in a plane. The modem gives the date and time to said telematics unit of said vehicle.

[00012] As per another aspect of the present subject matter, the vehicle control unit is being configured to calculate a ratio between said real time GPS distance and said ideal distance.

[00013] As per another aspect of the present subject matter, the control system configured to compare the ratio between said real time GPS distance and said ideal distance with a lookup table. The lookup table comprising a plurality of predetermined values of tyre pressure for a plurality of ratio between said real time GPS distance and said ideal distance.

[00014] As per another aspect of the present subject matter, the vehicle control unit being configured to determine an acceleration or deceleration state of the vehicle based on the speed of the drive unit received from the power control unit. The vehicle control unit being configured to determine a vehicle turning state and a vehicle gradient state based on the acceleration value received from the telematics unit.

[00015] As per another aspect of the present subject matter, the vehicle control unit being configured to determine a malfunction event based on the calculated tyre pressure, the acceleration or deceleration state, the vehicle turning, and the vehicle gradient state.

[00016] As per another aspect of the present subject matter, the vehicle control unit being configured to send an alert indication to an instrument cluster of the vehicle upon detection of the malfunction event. The instrument cluster being configured to generate one or more of an audio alert and a visual alert.

[00017] As per another aspect of the present subject matter, a power source i.e. driving unit being one of an internal combustion engine, a battery powered motor or both.

[00018] As per another embodiment of the present subject matter, a method for monitoring a tyre pressure of a vehicle, said method implemented by a system for monitoring tyre pressure, said method comprising the steps of: calculating by a control system, a speed of a drive unit of the vehicle where an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit; calculating by a telematics unit, a real time GPS speed of the vehicle, a real time GPS distance covered by the vehicle being calculated based on said real time GPS speed; and calculating by the control system, a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance.

[00019] As per an aspect of present subject matter, the control system comprising a power control unit, the method comprises the steps of: obtaining drive unit speed from a sensor by the power control unit, said speed of the drive unit of the vehicle being used to calculate the ideal distance of the vehicle; and obtaining from a temperature sensor by the power control unit, a temperature of the drive unit for determining the tyre pressure.

[00020] As per an aspect of present subject matter, the control system comprising a vehicle control unit, the method comprises the steps of: storing and processing received data from said power control unit by the vehicle control unit and said telematics unit of the vehicle; indicating a tyre pressure to a user of the vehicle in a current power cycle and in a next power cycle by the vehicle control unit; and deciding by the vehicle control unit, a running state of said vehicle.

[00021] As per an aspect of present subject matter, the method immobilizes the vehicle by the vehicle control unit, in an event exceeding a predetermined number of low tyre pressure indications.

[00022] As per an aspect of present subject matter, the method comprises the steps of: tracking by a GPS of the telematics unit, the vehicle in terms of a latitude and a longitude to enable the telematics unit to calculate the real time GPS distance; calculating by an accelerometer of the telematics unit, an acceleration value due to gravity along a 3-axis (X, Y, Z) in a plane; and communicating to a modem of the telematics unit, the date and time to said telematics unit.

[00023] As per an aspect of present subject matter, the method calculates a ratio between said real time GPS distance and said ideal distance by the vehicle control unit.

[00024] As per an aspect of present subject matter, the method comprises the steps of: tracking by a GPS of the telematics unit, the vehicle in terms of a latitude and a longitude to enable the telematics unit to calculate the real time GPS distance; calculating by an accelerometer of the telematics unit, an acceleration value due to gravity along a 3-axis (X, Y, Z) in a plane; and communicating to a modem of the telematics unit, the date and time to said telematics unit.

[00025] As per an aspect of present subject matter, the method calculates a ratio between said real time GPS distance and said ideal distance by the vehicle control unit.

[00026] As per an aspect of present subject matter, the method comprises the steps of: comparing, the ratio between said real time GPS distance and said ideal distance with a lookup table by said control system. The lookup table comprising a plurality of predetermined values of tyre pressure for a plurality of ratio between said real time GPS distance and said ideal distance. [00027] As per an aspect of present subject matter, the method comprises the steps of: determining by the vehicle control unit, an acceleration or deceleration state of the vehicle based on the speed of the drive unit received from the power control unit; determining by the vehicle control unit, a vehicle turning state and a vehicle gradient state based on the acceleration value received from the telematics unit; and determining by said vehicle control unit, a malfunction event based on the calculated tyre pressure, the acceleration or deceleration state, the vehicle turning, and the vehicle gradient state.

[00028] As per an aspect of present subject matter, the method comprises the steps of: receiving, said speed of the drive unit of the vehicle from said power control unit via a communication line; calculating, using a timer interrupt service routine, time for which the speed of the drive unit is being received; calculating acceleration, based on an old speed of the drive unit, a current speed of the drive unit, and the calculated time for which the speed of the drive unit is being received; replacing, the value of said old speed as the current speed; and comparing, said acceleration with a high threshold value and a low threshold value to determine an acceleration or deceleration state. Determining the acceleration or deceleration state, in the event when said acceleration being greater than the high threshold value or said acceleration being less than the low threshold value, and determining no acceleration state of the vehicle, in the event when said acceleration being lesser than the high threshold value or said acceleration being greater than the low threshold value and operating type pressure monitoring function only when no acceleration state of vehicle is determined.

[00029] As per an aspect of present subject matter, the method comprises the steps of: receiving, an accelerometer value from the accelerometer, using the telematics unit; calculating, a roll angle and a pitch angle based on the accelerometer value, using the telematics unit; comparing, said roll angle with a high threshold value and a low threshold value. Determining the roll angle, in the event when said roll angle being greater than said high threshold value or said roll angle being less than the low threshold value, and determining no vehicle turn state of the vehicle, in the event when said roll angle being lesser than the high threshold or said roll angle being greater than the low threshold value. Comparing, said pitch angle with a high threshold value and a low threshold value, determining the pitch angle, in the event when said pitch angle is being greater than said high threshold value or said pitch angle is being less than the low threshold value, and determining no vehicle gradient state of the vehicle, in the event when said pitch angle being lesser than the high threshold or said pitch angle being greater than the low threshold value and operating type pressure monitoring function only when no turn and no gradient state of vehicle is determined.

[00030] As per an aspect of present subject matter, the method comprises the steps of: sending by said vehicle control unit, an alert indication to an instrument cluster of the vehicle upon detection of the malfunction event; and generating, one or more of an audio alert and a visual alert by said instrument cluster of the vehicle.

[00031] As per an aspect of present subject matter, the method comprises resetting a vehicle starting state, by the user of the vehicle, using one or more user interaction elements of the vehicle.

[00032] Fig.l exemplarily illustrates a block diagram for a tyre pressure monitoring system 100. The tyre pressure monitoring system 100 includes a control system 101, a telematics system 102, and an instrument cluster system 104. The control system 101 includes a power control system 101(aa) and a vehicle control unit 101(ab). The power control system 101 (aa) includes a power control unit 101(c), a sensor 101(a) attached to a drive unit (not shown), and a temperature sensor 101(b). In the present embodiment, said sensor is a hall sensor, temperature sensor is a coil temperature sensor and the power control unit 101(c) is a motor control unit 101(c). The telematics system 102 includes a telematics unit 102 (e) a GPS device 102(a), an accelerometer 102(b), and a modem 102(c) connected to a data server 102(d). The instrument cluster system 104 includes an instrument cluster 104(c), a malfunction indicator (MIL) 104(a), and a beeper 104(b). Arrows in illustration represent the communication configured between the respective hardware either being one way or two way. The power control unit 101(c) calculates the speed of a drive unit (not shown) using the time taken for a step cycle of the hall sensor 101(a) output from the drive unit (not shown). In an embodiment, the drive unit is one of an internal combustion engine, a battery, a motor, or a combination thereof. In the present embodiment the drive unit (not shown) is a motor (not shown). The motor control unit 101 (c) also calculates a motor coil temperature using the output of a coil temperature sensor 101(b), for example, a thermistor (not shown), mounted on a stator coil. The motor control unit 101(c) communicates the motor speed and coil temperature to the vehicle control unit 101(ab) through a CAN Bus. The telematics unit 102(e) having the GPS device 102(a) gives the instantaneous location data of the vehicle in terms of Latitude and longitude. The accelerometer 102(b) provides the acceleration due to gravity along the 3 axes X, Y, Z. The modem 102(c) provides the date and time data to the telematics unit 102(e). The telematics unit 102(e) determines the instantaneous GPS speed of the vehicle by the rate of change of latitude and longitude values and the earth’s radius. The telematics unit 102(e) communicates the instantaneous GPS 102(a) speed, accelerometer 102(b) outputs and the date, time data to the vehicle control unit 101(ab) through the CAN Bus. The vehicle control unit 101(ab) is communicatively coupled with said power control system 101 (aa) and said telematics unit 102(e).

[00033] Fig.2 (a) and 2(b) exemplarily illustrates a flow chart for calculating the tyre pressure. The tyre pressure monitoring system having a control system 101 is configured to receive speed of the drive unit from a sensor (at step 105) and calculates the speed of the drive unit (not shown) of the vehicle, where an ideal distance to be covered by the vehicle is calculated based on said speed of the drive unit (at step 106). The telematics unit 102 (e) is configured to receive the real time GPS speed from the GPS device (at step 107) and calculate a real time GPS speed of the vehicle, where a real time GPS distance covered by the vehicle is calculated based on said real time GPS speed (at step 108). The control system 101 is configured to calculate a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance (at step 109).

[00034] The ratio between said real time GPS distance and said ideal distance is compared with a lookup table (at step 110). The lookup table comprises of a plurality of predetermined values of tyre pressure for a plurality of ratio between said real time GPS distance and said ideal distance. When the tyre pressure of the vehicle reduces below the recommended pressure, the ratio of the real time GPS distance and the ideal distance reduces below 1 (at step 111). The reduction in the ratio is directly proportional to the reduction in rolling radius which in turn is directly proportional to the reduction tyre pressure. The vehicle control unit (101(ab)) is configured to determine a malfunction event based on the calculated tyre pressure, the acceleration or deceleration state, the vehicle turning, and the vehicle gradient state (at step 112). In order to make the user aware of the tyre pressure of the vehicle, the vehicle control unit 101(ab) sends indications and alerts signals by one or more of a blinking of the malfunction indicator 104(a) (MIL) on the instrument cluster system 104 and beeping the beeper 104(b) of the instrument cluster system 104 through the CAN communication (at step 113), up to a pre determined range of tyre pressure, for example from normal tyre pressure up to say 30 psi to 21 psi. If the tyre pressure does not reduce below a recommended pressure, no malfunction is detected (at step 114). Also, when the tyre pressure reduces below safety critical levels, for example below 20 psi, which might lead to wheel rim bend while moving over the gradient or pothole, the vehicle control unit 101(ab) immobilizes the vehicle through the CAN communication. However, in case of such malfunction event, the instrument cluster system 104 can generate one or more of an audio alerts and a visual alert. The vehicle can be re-mobilized by resetting a vehicle starting state, by the user of the vehicle, using one or more user interaction elements of the vehicle. The vehicle starting state is the state in which vehicle becomes mobile. The user interaction elements include switches, brakes, touch buttons, and the like and the combination thereof. In order to mobilize the vehicle, the user has to reset the brake, running mode of the vehicle, and park switch. The system 100 also gives the warning on a user mobile application (not shown) about the immobilization of the vehicle.

[00035] After resetting the status, the vehicle control unit (101(ab)) allows the user to drive the vehicle to a pre-determined distance and up to a predetermined number of low tyre pressure indications without refding air in the tyres. If the tyres are not inflated after the pre-determined distance, it again immobilizes the vehicle. The status of tyre pressure detection is stored in internal non-volatile memory by the vehicle control unit 101(ab) to continue the indication after the end of a power cycle or start of a new trip. In the present disclosed system 100, tyre pressure reduction can be sensed without use of actual pressure sensors. No additional wheel speed sensor is required. The hall sensor 101(a) output signals are used to measure the wheel speed. Reduction in tyre pressure can be sensed even if all the wheels deflate by equal amounts as the method of detection the tyre pressure is independent of difference in wheel speeds. The customer is proactively informed at different levels of tyre pressure preventing reduction in total range of the vehicle and mechanical failure of the rim. This system 100 also, eliminates the problem of reduction of mileage.

[00036] Fig.3 exemplarily illustrates an elaborated flow chart for calculating the tyre pressure. The power control unit 101(c) receives the speed of the drive unit (not shown) of the vehicle (at step 201), wherein an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit (at step 202). The telematics unit 102(e) calculates a real time GPS speed of the vehicle (at step 203), where a real time GPS distance covered by the vehicle being calculated based on said real time GPS speed (at step 205). The telematics unit 102(e) also checks acceleration/deceleration, vehicle turning, and vehicle gradient state of the vehicle (at step 204). When vehicle is taking a turn or is at gradients, the vehicle accelerates and decelerates, the speed during acceleration and deceleration cannot be used to detect the actual tyre pressure. The threshold limits for the gradient, a roll angle and the acceleration are defined for vehicle control unit 101 (ab) to calculate the GPS Speed. When these three parameters go higher than the pre-set thresholds, the vehicle control unit 101(ab) stops accumulation of GPS speed. The GPS device 102(a) speed output of the telematics unit 102(e) is inaccurate when the vehicle takes a turn or during vehicle’s acceleration due to Hysteresis effect, so due to this reason, accumulation of GPS speed is stopped. Further, the tyre pressure changes with respect to the atmospheric temperature, so the pre -determined thresholds changes with respect to the temperature change in the air. Also, the temperature from the stator coil (not shown) mounted on the motor (not shown) is measured and is communicated by the power control unit 101(c) to the vehicle control unit 101(ab). This temperature is calculated using a temperature correction factor calculator (at step 208). The stator coil temperature is corrected based on the correction factors (at step 211), and then the distance ratio is calculated to detect the tyre pressure (at step 207). In an embodiment, where the drive unit is an internal combustion engine (IC engine), the temperature from the IC engine (not shown) is measured by the vehicle control unit 101(ab). This temperature is calculated using a temperature correction factor calculator. The temperature is corrected based on the correction factors, and then the distance ratio is calculated to detect the tyre pressure.

[00037] Fig.4 exemplarily illustrates a flow chart for calculating acceleration of the vehicle. The vehicle control unit 101(ab) receives the motor speed from the power control system 101(aa) (MCU) (at step 301) and calculates the time for which the speed is measured, using an Interrupt Service Routine (ISR) (at step 302). The vehicle control unit 101(ab) calculates the acceleration by taking difference of an old speed and a current speed of the vehicle and taking the ratio of thus obtained speed with time (at step 303) . The value of the old speed is replaced with the current speed (at step 304). The vehicle control unit 101(ab) compares the acceleration with a threshold value of acceleration stored in the memory of the vehicle (at step 305). If the value of instantaneous acceleration is greater than the value of a high threshold of the acceleration or the value is less than a low threshold of the acceleration, then the acceleration detect is equal to 1. Thus, the vehicle is being determined as accelerating (at step 306) and no tyre pressure is being checked during this condition. If the value of instantaneous acceleration is lesser than the high threshold value or said acceleration is greater than the low threshold value, then the acceleration detect is equal to 0 (at step 307). Thus, the vehicle is being determined as not accelerating and tyre pressure is being checked during this condition. As a result, the vehicle and the user safety are ensured. If the vehicle is accelerating i.e. acceleration detect = 1, the speed of the vehicle is not accumulated. [00038] Fig.5 exemplarily illustrates a flowchart for calculating the roll angle and a pitch angle of the vehicle so as to not record the tyre pressure when the vehicle is at gradients or at turning condition. The vehicle control unit 101(ab) receives the speeds from the power control unit 101(c) and the telematics unit 102(e) (at step 401), calculates the roll angle and the pitch angle of the vehicle by utilizing the acceleration due to gravity along the vehicle’s 3 axes X, Y, Z (at step 402) as measured by the telematics unit 102(e). The vehicle control unit 101(ab) compares the roll angle with a threshold value stored in the memory of the vehicle (at step 403). If the value of the roll angle is greater than the value of a high threshold of the roll angle or the value is less than a low threshold value of the roll angle, then the vehicle is determined to be turning and turn detect is equal to 1 (at step 404) and no vehicle speed data is accumulated during this condition. Thus, the vehicle is taking a turn, and if the vehicle turn detect is equal to 0 (at step 405), then no vehicle turn is detected, vehicle speed data is accumulated during this condition. Further, If the value of pitch angle is greater than the value of a high threshold value of the pitch angle or the value is less than the value of a low threshold value of the pitch angle (at step 406), the vehicle gradient detect is equal to 1 i.e. the vehicle is determined to be moving on gradient (at step 407) and no vehicle speed data is accumulated during this condition. If the vehicle gradient detect is equal to 0 that means the vehicle in not moving on gradient (at step 408) and vehicle speed data is accumulated during this condition. The threshold limits for the gradient, the roll angle and the acceleration are defined in the vehicle control unit 101(ab). When the above mentioned three parameters go beyond the preset thresholds, the vehicle control unit 101(ab) suspends accumulation of the GPS Speed thereby ensuring error free tyre pressure monitoring system as well as safety of the rider. Many other improvements and modifications may be incorporated herein without deviating from the scope of the invention. List of Reference numerals

100: Tyre pressure monitoring system

101: Control system of 100

101(aa): Power control system of 100

101 (ab): Vehicle control unit of 100

101(a): Sensors of 101

101(b): Temperature sensor of 101

101(c): Power Control unit of 101

102: Telematics system of 100

102(a): GPS of 102

102(b): Accelerometer of 102

102(c): Modem of 102

102(d): Data server of 102

102(e): Telematics unit of 102

104: Instrument cluster system of 100

104(a): Malfunction indicator (MIL) of 104

104 (b): Beeper of 104

104(c): Instrument cluster of 104

308: Powered object CAN bus

Claims

We claim:

1. A system for monitoring a tyre pressure (100) in a vehicle, said system (100) comprising: a control system (101) being configured to calculate a speed of a drive unit (not shown) of the vehicle, wherein an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit; and a telematics system (102) being configured to calculate a real time GPS speed of the vehicle, wherein a real time GPS distance covered by the vehicle being calculated based on said real time GPS speed; wherein said control system (101) being configured to calculate a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance.

2. The system for monitoring the tyre pressure (100) as claimed in claim 1, said control system (101) includes one or more of a power control system (101 (aa)) and a vehicle control unit (101(ab)).

3. The system for monitoring the tyre pressure (100) as claimed in claim 2, wherein said power control system (101(aa)) comprising: a power control unit 101(c) configured to communicate with vehicle control unit 101(ab); a sensor (101(a)) configured to obtain speed of the drive unit of the vehicle to calculate the ideal distance of the vehicle; and a temperature sensor (101(b)) configured to obtain a temperature of the drive unit for determining the tyre pressure.

4. The system for monitoring the tyre pressure (100) as claimed in claim 1 or claim 2, wherein said vehicle control unit (101(ab)) being configured to communicate with said power control unit (101(c)) and said telematics unit (102(e)) to store and process received data from said power control unit (101(c)) and said telematics unit (102(e));

1 the vehicle control unit (101 (ab)) being configured to indicate a tyre pressure to a user of the vehicle in a current power cycle and in a next power cycle; said indication being through one or more of an audio and visual indication on a display device; and the vehicle control unit (101(ab)) being configured to decide a running state of said vehicle.

5. The system for monitoring the tyre pressure (100) as claimed in claim 4, wherein the vehicle control unit (101(ab)) immobilizes the vehicle after a predetermined number of low tyre pressure indications.

6. The system for monitoring the tyre pressure (100) as claimed in claim 1, wherein said telematic system (102) includes a telematics unit (102e), a GPS device (102(a)), an accelerometer (102(b)), and a modem (102(c)) connected to a data server (102(d)), wherein said GPS device (102(a)) tracks the vehicle in terms of a latitude and a longitude to enable the telematics unit (102e) to calculate the real time GPS distance; said accelerometer (102(b)) calculates an acceleration value due to gravity along a 3-axis (X, Y, Z) in a plane; and said modem (102(c)) gives the date and time to said telematics unit (102(e)) of said vehicle.

7. The system for monitoring the tyre pressure (100) as claimed in claim 1 or claim 4, wherein the vehicle control unit (101(ab)) being configured to calculate a ratio between said real time GPS distance and said ideal distance.

8. The system for monitoring the tyre pressure (100) as claimed in claim 7, wherein said control system (101) configured to compare the ratio between said real time GPS distance and said ideal distance with a lookup table; wherein said lookup table comprising a plurality of predetermined values of tyre pressure for a plurality of ratio between said real time GPS distance and said ideal distance.

2

9. The system for monitoring the tyre pressure (100) as claimed in claim 2, wherein said vehicle control unit (101(ab)) being configured to determine an acceleration or deceleration state of the vehicle based on the speed of the drive unit received from the power control unit (101(c)); and said vehicle control unit (101(ab)) being configured to determine a vehicle turning state and a vehicle gradient state based on the acceleration value received from the telematics unit (102(e)).

10. The system for monitoring the tyre pressure (100) as claimed in claim 8 or claim 9, wherein said vehicle control unit (101(ab)) being configured to determine a malfunction event based on the calculated tyre pressure, the acceleration or deceleration state, the vehicle turning, and the vehicle gradient state.

11. The system for monitoring the tyre pressure (100) as claimed in claim 10, wherein the vehicle control unit (101(ab)) being configured to send an alert indication to an instrument cluster system (104) of the vehicle upon detection of the malfunction event; wherein the instrument cluster system (104) being configured to generate one or more of an audio alert and a visual alert.

12. The system for monitoring the tyre pressure (100) as claimed in claim 1, a power source being one of an internal combustion engine, a battery powered motor, a motor, or a combination thereof.

13. A method for monitoring a tyre pressure in a vehicle, said method implemented by a system (100) for monitoring tyre pressure, said method comprising the steps of: calculating by a control system (101), a speed of a drive unit (not shown) of the vehicle (step 205) where an ideal distance to be covered by the vehicle being calculated based on said speed of the drive unit (step 206);

3 calculating by a telematics unit (102e), a real time GPS speed of the vehicle, a real time GPS distance covered by the vehicle being calculated based on said real time GPS speed; and calculating by the control system (101), a tyre pressure of the vehicle based on said real time GPS distance and the ideal distance.

14. The method for monitoring the tyre pressure as claimed in claim 13, wherein said control system (101) comprising a power control unit (101(c)), the method comprises the steps of: obtaining said drive unit speed from a sensor (101(a)) by the power control unit (101(c)), said speed of the drive unit of the vehicle being used to calculate the ideal distance of the vehicle; and obtaining from a temperature sensor (101(b)) by the power control unit (101(c)), a temperature of the drive unit for determining the tyre pressure.

15. The method for monitoring the tyre pressure as claimed in claim 13, wherein said control system (101) comprising a vehicle control unit (101(ab)), the method comprises the steps of: storing and processing received data from said power control unit (101(c)) by the vehicle control unit (101(ab)) and said telematics unit (102(e)) of the vehicle; indicating a tyre pressure to a user of the vehicle in a current power cycle and in a next power cycle by the vehicle control unit (101(ab)); and deciding by the vehicle control unit (101(ab)), a running state of said vehicle.

16. The method for monitoring the tyre pressure as claimed in claim 15, wherein immobilizing the vehicle by the vehicle control unit (101(ab)), in an event exceeding a predetermined number of low tyre pressure indications.

17. The method for monitoring the tyre pressure as claimed in claim 13, wherein the method comprises the steps of:

4 tracking by a GPS of the telematics unit (102(e)), the vehicle in terms of a latitude and a longitude to enable the telematics unit (102(e)) to calculate the real time GPS distance; calculating by an accelerometer (102(b)) of the telematics unit (102(e)), an acceleration value due to gravity along a 3-axis (X, Y, Z) in a plane; and communicating to a modem (102(c)) of the telematics unit (102(e)), the date and time to said telematics unit (102(e)).

18. The method for monitoring the tyre pressure as claimed in claim 13 or claim 15, wherein calculating a ratio between said real time GPS distance and said ideal distance by the vehicle control unit (101(ab)).

19. The method for monitoring the tyre pressure as claimed in claim 18, wherein, the method comprises the steps of: comparing, the ratio between said real time GPS distance and said ideal distance with a lookup table by said control system (101); wherein said lookup table comprising a plurality of predetermined values of tyre pressure for a plurality of ratio between said real time GPS distance and said ideal distance.

20. The method for monitoring the tyre pressure as claimed in claim 15, wherein said method comprises the steps of: determining by the vehicle control unit (101(ab)), an acceleration or deceleration state of the vehicle based on the speed of the drive unit received from the power control unit (101(c)); determining by the vehicle control unit (101(ab)), a vehicle turning state and a vehicle gradient state based on the acceleration value received from the telematics unit (102(e)); and determining by said vehicle control unit (101(ab)), a malfunction event based on the calculated tyre pressure, the acceleration or deceleration state, the vehicle turning, and the vehicle gradient state.

21. The method for monitoring the tyre pressure as claimed in claim 20, wherein the method comprises the steps of:

5 receiving, said speed of the drive unit of the vehicle (step 301) from said power control unit (101(c)) via a communication line; calculating, using a timer interrupt service routine (step 302), time for which the speed of the drive unit being received; calculating acceleration (step 303), based on an old speed of the drive unit, a current speed of the drive unit, and the calculated time for which the speed of the drive unit being received; replacing (step 304), the value of said old speed as the current speed; and comparing (step 305), said acceleration with a high threshold value and a low threshold value to determine an acceleration or deceleration state; determining the acceleration or deceleration state, in the event when said acceleration being greater than the high threshold value or said acceleration being less than the low threshold value (step 306); and determining no acceleration state of the vehicle, in the event when said acceleration being lesser than the high threshold value or said acceleration being greater than the low threshold value (step 307) and operating type pressure monitoring function only when no acceleration state of vehicle is determined.

22. The method for monitoring the tyre pressure as claimed in claim 20, wherein the method comprises the steps of: receiving (step 401), an accelerometer value from the accelerometer (102(b)), using the telematics unit (102(e)); calculating, a roll angle and a pitch angle (step 402) based on the accelerometer value, using the telematics unit (102(e)); comparing, said roll angle with a high threshold value and a low threshold value (step 403); determining the roll angle, in the event when said roll angle being greater than said high threshold value or said roll angle being less than the low threshold value;

6 determining no vehicle turn state of the vehicle (step 404), in the event when said roll angle being lesser than the high threshold or said roll angle being greater than the low threshold value; comparing, said pitch angle with a high threshold value and a low threshold value (step 403); determining the pitch angle, in the event when said pitch angle being greater than said high threshold value or said pitch angle being less than the low threshold value; and determining no vehicle gradient state of the vehicle (step 404), in the event when said pitch angle being lesser than the high threshold or said pitch angle being greater than the low threshold value and operating type pressure monitoring function only when no turn and no gradient state of vehicle is determined.

23. The method for monitoring the tyre pressure as claimed in claim 20, wherein, the method comprises the steps of: sending by said vehicle control unit (101(ab)), an alert indication to an instrument cluster (104c) of the vehicle upon detection of the malfunction event; and generating, one or more of an audio alert and a visual alert by said instrument cluster (104c) of the vehicle.

24. The method for monitoring the tyre pressure as claimed in claim 16, wherein the method comprises resetting a vehicle starting state, by the user of the vehicle, using one or more user interaction elements of the vehicle.

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