GB2505943B

GB2505943B - Tyre pressure monitoring

Info

Publication number: GB2505943B
Application number: GB1216554.4A
Authority: GB
Inventors: Fry Matthew; Heirons Gary
Original assignee: Knorr Bremse Systems for Commercial Vehicles Ltd
Current assignee: Knorr Bremse Systems for Commercial Vehicles Ltd
Priority date: 2012-09-17
Filing date: 2012-09-17
Publication date: 2019-08-14
Anticipated expiration: 2032-09-17
Also published as: GB201216554D0; GB2505943A

Description

Tyre Pressure Monitoring

The invention relates to a trailer tyre pressure monitoring system.

Correct inflation of tyres on a vehicle, particularly on heavy commercial vehicles suchas trailers is important as incorrect tyre pressures can lead to stability problems and ifthe tyre pressure is too low, the tyre life will be reduced and the fuel consumption willincrease.

Tyre pressure monitoring systems are now available for trailers but suffer from theproblem that unless the trailer is connected to a tractor, no power is available to readand display the tyre pressure. One possible solution to this to use a trailer informationmodule which can read and store the data. Such a system is described inUS2010292898.

Although trailer information modules have significant operational advantages fortrailer operators, many trailer operators do not wish to incur the additional expense ofthe information module and they have achieved only a limited market share.

The present invention seeks to provide apparatus to display tyre pressures for acommercial vehicle trailer.

According to the invention there is provided tyre pressure monitoring system inaccordance with the features of Claim 1

Preferably, in a system for a trailer having front and rear axles, in which the display ofthe tyre pressure for the respective front and rear axles is changed by means of atouch gesture along a longitudinal axis of the device screen.

Preferably in a system for a trailer having two or more tyres on a wheel end of anaxle, in which the display of the respective tyre pressures of the said tyres is changedby means of a touch gesture along a lateral axis of the device screen.

Preferably, the communication interface comprises a 802.11 wireless interface, whichinterface is adapted to transmit an SSID, the trailer identifier comprising the SSID.

The system of the invention advantageously provides for an easy method ofnavigating the display of tyre pressures.

Exemplary embodiments of the invention will now be described in greater detail withreference to the drawings in which:

Fig. 1 shows a trailer electronic braking system

Fig. 2 shows a schematic diagram of the brake control with a trailer accessmicrocontroller

Fig. 3 shows a screen of a portable electronic device showing tyre pressuresfor inside rear tyres

Fig. 4 shows a screen of a portable electronic device showing tyre pressuresfor outside rear tyres

Fig. 5 shows a screen of a portable electronic device showing tyre pressuresfor inside front tyres

The utility vehicle trailer has a steerable front axle with front wheels 1, 2 and a rearaxle with rear wheels 3, 4. Rotational wheel speed sensors 5-8 are in each caseassigned to the front wheels 1, 2 and the rear wheels 3, 4, and are connected by wayof electric lines 9-12 with an electropneumatic brake pressure control module 13(EBS module) which is primarily assigned to the rear axle brakes. One brake 14-17 isin each case assigned to the front wheels 1, 2 and the rear wheels 3, 4, which brake 14-17 can be applied by means of brake cylinders 18, 19 of the front axle or spring-loaded brake cylinders 20, 21 of the rear axle. The trailer is provided with tyrepressure sensors associated with each wheel, which can measure the pressure in eachtyre. The tyre pressure sensors are located inside the respective tyre and measure thetyre pressure and temperature and transmit this data wirelessly to the tyre pressuremonitoring system, which is attached to the trailer CAN bus 35.

The braking system of the trailer vehicle can be connected by way of threeconnections, specifically a pneumatic supply line connection 22, a pneumatic controlline connection 23 and an electric control connection 24, with the braking system of atractor or a further trailer. The electric control line 24 provides the ISO 11992 CANdata connection.

The supply line connection 22 is connected by way of a filter valve 25 and a parkingvalve 26 with an air brake reservoir 27. From the air brake reservoir 27, a pneumaticline 28, 30 leads to a supply input of the pressure control module 13 andelectropneumatic valve 32, which is adapted to supply ABS functionality. In addition,a pneumatic line 29 branches off the parking valve 26 to the pressure control module13. A pneumatic line 30 extends between the parking valve 26 and the air brakereservoir 27.

The electropneumatic valve 32 is assigned jointly to both brake cylinders 18, 19 of thefront axle and is connected with the brake cylinder 18 by way of a pneumatic line 33and with the brake cylinder 19 by way of a pneumatic line 34. The valve 32 has twoelectric control inputs which are connected by way of "one" electric communicationline 35 such as CAN, shown here only schematically, with the pressure controlmodule 13.

Furthermore, the valve 32 has a pneumatic control input 36 which is connected byway of a filter valve 37 with the pneumatic control connection 23. The pneumaticcontrol input 36 is also connected by way of a pneumatic control line 38 with apneumatic control input of the pressure control module 13. The pressure controlmodule 13 has an integrated pressure sensor (not shown) which measures the pressurein the pneumatic control line 38, that is, the control pressure present at the pneumatic control input 36 of the electropneumatic valve, which control pressure is identical tothe maximal pressure which can be controlled into the brake cylinders 18, 19.

The pressure control module 13 has pneumatic outputs 39-42 which are connected byway of assigned pneumatic lines with the spring brake cylinders 20 or 21.

Furthermore, air bellows 43, 44 are provided at the rear axle and permit adetermination of the axle load, particularly of the dynamic axle load during brakingand starting. The air bellows 43, 44 are connected by way of pneumatic lines with thepressure control module 13. The pressure control module 13 has an integratedpressure sensor (not shown) which measures the pressure in the air bellows 43, 44.Correspondingly the pressure in airbags 45, 46 provided at the front axle, which hereare electrically controlled, may be detected by an optional pressure transducer.

To provide stability control a lateral acceleration sensor is provided, which may alsobe integrated with a yaw sensor, and the output of the lateral acceleration sensor is fedto the pressure control module/ECU 13. Typically the lateral acceleration sensor isintegrated into the pressure control module/ECU 13. In the event that lateralacceleration on the trailer is detected, the pressure control module can provide forincreased brake force at the front and/or rear axles. When the lateral accelerationsensor detects lateral acceleration on the frailer in which it is installed, the sensorgenerates a signal setting the stability control to active.

The pressure control module 13 receives data from the wheel speed sensors on thetrailer and also receives a signal indicating whether the brake pedal in the vehicle cabis depressed or not, as well as the brake pressure demand. The pressure controlmodule 13 further receives signals from the tyre pressure monitors on each wheel.

Figure 2 shows schematically the arrangement of the trailer access microcontrollerwith the trailer electronic braking system. The trailer electronic braking system isonly partially illustrated for reasons of clarity but includes the pressure controlmodule 13 which is shown receiving wheel speed signals from wheel speed sensors5,6. The pressure control module 13 also receives inputs from the lift axles showingthe position of the lift axles and also the steering lock. The pressure control module 13 also receives power and data via an electrical connection from the tractor and isalso attached to an ISO 11992 CAN databus . A trailer access point (TAP) comprising microcontroller 60 with a CAN interface isalso provided, which is powered from the electrical connection. The microcontroller60 itself comprises an interface to the on-board electronic systems and the trailerelectronic braking system and an interface for sending and receiving data in a wirelessformat 61. The communications interface 61 can comprise one or more of a 802.11transceiver or Bluetooth transceiver or radio transceiver. The trailer access point isconnected to the CAN bus on the trailer and so is able to receive data from otherdevices on the CAN bus. The trailer access point can further be provided with USBports, which enables the addition of peripheral devices on the trailer. An exemplarydevice on the CAN bus is the rear obstacle detector 62 and an exemplary deviceattached to the USB port is a reversing camera. USB is preferable in this case as thecamera would generate large amounts of data compared to the remaining data on theCAN bus.

The trailer access point can be mounted in a housing similar to that used for a trailerinformation module but without a display being necessary. If a display is needed, itwould be possible to use a bistable cholestatic display or zero power LCD display.

In use, when the trailer access point is powered, the provision of the access pointenables the data from the devices to be read by another device with a client browser.Such devices could include a tractor navigation system or a smartphone. It wouldalso be possible to use a laptop. The invention enables the data to be made availableto the driver during normal operation as well as to a service technician formaintenance purposes at low cost using standard devices. The data provided to thedevice with a client browser includes the tyre pressure at each wheel.

The trailer access point comprises the microcontroller with an interface to the on-board electronic systems and the trailer electronic braking system and an interface forsending and receiving data in a wireless format; the microcontroller is adapted tooperate with an optional display as described above and also with the onboarddiagnostics.

Figures 3 to 5 show a display screen of a portable electronic device such as a smartphone with touch screen control, which displays a representation of the trailer’s reartyres in figures 3 and 4 and the front tyres in Figure 5. Figure 3 shows the tyrepressures at the rear outside tyres. Figure 4 shows the tyre pressure at the inside reartyres and Figure 5 shows the tyre pressures at the front tyres. The user can usegestures such as sliding a finger laterally across the screen to switch between theinside and outside tyres and longitudinally across the screen to switch between thetyres on front and rear axles.

Although the trailer access point has been specifically described as a microcontroller,it would be possible to incorporate the functionality as an auxiliary function in thetrailer electronic brake control unit. The trailer electronic brake control unit receivesthe operational data from the sensor outputs but would need to have an additionalcommunication interface to be able to provide the interface to the standards compliantbrowser or client.

Claims

1. A tyre pressure monitoring system for a trailer comprising an ECU/pressurecontrol module for controlling brakes on the trailer and a microcontroller connected toa standards compliant communication bus on said trailer, the pressure control modulebeing adapted to receive data inputs from tyre pressure sensors on the trailer, whereinthe microcontroller further comprises means to interface to trailer electronics and acommunications interface, wherein the system is further adapted to transmit a traileridentifier, such that the trailer identifier can be paired with a further device, whichfurther device is adapted to display a tyre pressure on the trailer such that datareceived from the tyre pressure sensors can be wirelessly transmitted in standardscompliant manner to the further device, which further device is remote or distinctfrom the trailer, which further device is adapted to display tyre pressure informationso received using a standards compliant client.

2. A tyre pressure monitoring system according to Claim 1, wherein the furtherdevice is provided with a touch screen and tyre pressure of a second wheel can bedisplayed by the further device in place of the first tyre pressure by means of a touchgesture on the touch screen.

3. A tyre pressure monitoring system according to Claim 2 for a trailer havingfront and rear axles, in which the display of the tyre pressure for the respective frontand rear axles is changed by means of a touch gesture along a longitudinal axis of thedevice screen.

4. A tyre pressure monitoring system according to Claim 2 or Claim 3 for atrailer having two or more tyres on a wheel end of an axle, in which the display of therespective tyre pressures of the said tyres is changed by means of a touch gesturealong a lateral axis of the device screen.

5. A tyre pressure monitoring system according to any one of Claims 1 to 4,wherein the communication interface comprises a 802.11 wireless card, which card isadapted to transmit an SSID, the trailer identifier comprising the SSID.