GB2505943A

GB2505943A - A trailer tyre pressure monitoring system

Info

Publication number: GB2505943A
Application number: GB201216554A
Authority: GB
Inventors: Matthew Fry; Gary Heirons
Original assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH; Knorr Bremse Systems for Commercial Vehicles Ltd
Current assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH; Knorr Bremse Systems for Commercial Vehicles Ltd
Priority date: 2012-09-17
Filing date: 2012-09-17
Publication date: 2014-03-19
Anticipated expiration: 2032-09-17
Also published as: GB2505943B; GB201216554D0

Abstract

A trailer tyre pressure monitoring system adapted to receive data inputs from tyre pressure sensors on the trailer comprises: a microcontroller 60 connected to a standards compliant communication bus on the trailer and an interface to trailer electronics and a wireless communications interface. The system is further adapted to transmit a trailer identifier, such that the trailer identifier can be paired with a further device capable of displaying a tyre pressure on the trailer. The further device may be provided with a LCD touch screen for displaying the pressure data.

Description

Tyre Pressure MonitorinQ The invention relates to a trailer tyre pressure monitoring system.

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

Tyre pressure monitoring systems are now available for trailers but suffer from the problem that unless the trailer is connected to a tractor, no power is available to read and display the tyre pressure. One possible solution to this to use a trailer information module which can read and store the data. Such a system is described in US2010292898.

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

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

According to the invention there is provided tyre pressure monitoring system for a trailer comprising a microcontroller connected to a standards compliant communication bus on said trailer and is adapted to receive data inputs from tyre pressure sensors on the trailer, wherein the system further comprises means to interface to trailer electronics and a communications interface, wherein the system is further adapted to transmit a trailer identifier, such that the trailer identifier can be paired with a further device, which further device is adapted to display a tyre pressure on the trailer.

Preferably, the further device is provided with a touch screen wherein lyre pressure of a second wheel can be displayed by the further device in place of the first tyre pressure by means of a touch gesture on the touch screen.

Preferably, in a system for a trailer having front and rear axles, in which the display of the tyre pressure for the respective front and rear axles is changed by means of a touch 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 an axle, in which the display of the respective tyre pressures of the said tyres is changed by means of a touch gesture along a lateral axis of the device screen.

Prefcrably, the communication interfaec comprises a 802.11 wireless interface, which interface is adapted to transmit an SSID, the trailer identifier comprising the SSID.

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

Exemplary embodiments of the invention will now be described in greater detail with reference 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 access microcontroller Fig. 3 shows a screen of a portable electronic device showing tyre pressures for inside rear tyres Fig. 4 shows a screen of a portable electronic device showing tyre pressures for outside rear tyres Fig. 5 shows a screen of a portable electronic device showing tyre pressures for inside front tyres The utility vehicle trailer has a steerable front axle with front wheels 1, 2 and a rear axle with rear wheels 3, 4. Rotational wheel speed sensors 5-8 are in each ease assigned to the front wheels 1, 2 and the rear wheels 3, 4, and are connected by way of electric lines 9-12 with an eleetropneumatie brake pressure control module 13 (EBS module) which is primarily assigned to the rear axle brakes. One brake 14-17 is in 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. Thc trailer is provided with tyre pressure sensors associated with each wheel, which can measure the pressure in each tyre. The tyre pressure sensors are located inside the respective tyre and measure the tyre pressure and temperature and transmit this data wirelessly to the tyre pressure monitoring system, which is attached to the trailer CAN bus 35.

The braking system of the trailer vehicle can be connected by way of three connections, specifically a pneumatic supply line connection 22, a pneumatic control line connection 23 and an electric control connection 24, with the braking system of a tractor or a further trailer. The electric control line 24 provides the ISO 11992 CAN data connection.

The supply line connection 22 is connected by way of a filter valve 25 and a parking valve 26 with an air brake reservoir 27. From the air brake reservoir 27, a pneumatic line 28, 30 leads to a supply input of the pressure control module 13 and electropneumatie 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 module 13. A pneumatic line 30 extends between the parking valve 26 and the air brake reservoir 27.

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

Furthermore, the valve 32 has a pneumatic control input 36 which is connected by way of a filter valve 37 with the pneumatic control connection 23. The pneumatic control input 36 is also connected by way of a pneumatic control line 38 with a pneumatic control input of the pressure control module 13. The pressure control module 13 has an integrated pressure sensor (not shown) which measures the pressure in 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 to the 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 by way 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 a determination of the axle load, particularly of the dynamic axle load during braking and starting. The air bellows 43,44 arc connected by way of pneumatic lines with the prcssurc control modulc 13. The pressure control modulc 13 has an integrated pressure 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 here are electrically controlled, may be detected by an optional pressure transducer.

To provide stability control a lateral acceleration sensor is provided, which may also be integrated with a yaw sensor, and the output of the lateral acceleration sensor is fed to the pressure control module/ECU 13. Typically the lateral acceleration sensor is integrated into the pressure control module/ECU 13. In the event that lateral acceleration on the trailer is detected, the pressure control module can provide for increased brake force at the front and/or rear axles. When the lateral acceleration sensor detects lateral acceleration on the trailer in which it is installed, the sensor generates a signal setting the stability control to active.

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

Figure 2 shows schematically the arrangement of the trailer access microcontroller with the trailer electronic braking system. The trailer electronic braking system is only partially illustrated for reasons of clarity but includes the pressure control module 13 which is shown receiving wheel speed signals from wheel speed sensors 5,6. The pressure control module 13 also receives inputs from the lift axles showing the 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 is also attached to an ISO 11992 CAN databus.

A trailer access point (TAP) comprising microcontroller 60 with a CAN interface is also provided, which is powered from the electrical connection. The microcontroller itself comprises an interface to the on-board electronic systems and the trailer electronic braking system and an interface for sending and receiving data in a wireless format 61. The communications interface 61 can comprise one or more of a 802.11 transceiver or Bluetooth transceiver or radio transceiver. The trailer access point is connected to the CAN bus on the trailer and so is able to receive data from other devices on the CAN bus. The trailer access point can further be provided with USB ports, which enables the addition of peripheral devices on the trailer. An exemplary device on the CAN bus is the rear obstacle detector 62 and an exemplary device attached to the USB port is a reversing camera. USB is preferable in this ease as the camera would generate large amounts of data compared to the remaining data on the CAN bus.

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

In use, when the trailer access point is powered, the provision of the access point enables 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 would also be possible to use a laptop. The invention enables the data to be made available to the driver during normal operation as well as to a service technician for maintenance purposes at low cost using standard devices. The data provided to the device 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 for sending and receiving data in a wireless format; the microcontroller is adapted to operate with an optional display as described above and also with the onboard diagnostics.

Figures 3 to 5 show a display screen of a portable electronic device such as a smart phone with touch screen control, which displays a representation of the trailer's rear tyres in figures 3 and 4 and the front tyres in Figure 5. Figure 3 shows the tyre pressures at the rear outside tyres. Figure 4 shows the tyre pressure at the inside rear tyres and Figure 5 shows the tyre pressures at the front tyres. The user can use gestures such as sliding a finger laterally across the screen to switch between the inside and outside tyres and longitudinally across the screen to switch between the tyres 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 the trailer electronic brake control unit. The trailer electronic brake control unit receives thc operational data from the sensor outputs but would need to have an additional communication interfitce to be able to provide the interfitce to the standards compliant browser or client.

Claims

Claims 1. A tyre pressure monitoring system for a trailer comprising a microcontroller connected to a standards compliant communication bus on said trailer and is adapted to receive data inputs from tyre pressure sensors on the trailer, wherein the system further comprises means to interface to trailer electronics and a communications interface, wherein the system is further adapted to transmit a trailer identifier, such that the trailer identifier can be paired with a further device, which further device is adapted to display a tyre pressure on the trailer.
2. A tyre pressure monitoring system according to Claim 1, wherein the further device is provided with a touch screen and tyre pressure of a second wheel can be displayed by the further device in place of the first tyre pressure by means of a touch gesture on the touch screen.
3. A tyre pressure monitoring system according to Claim 2 for a trailer having front and rear axles, in which the display of the tyre pressure for the respective front and rear axles is changed by means of a touch gesture along a longitudinal axis of the device screen.
4. A tyre pressure monitoring system according to Claim 2 or Claim 3 for a trailer having two or more tyres on a wheel end of an axle, in which the display of the respective tyre pressures of the said tyres is changed by means of a touch gesture along a lateral axis of the device screen.
5. A tyrc pressure monitoring system according to any one of Claims I to 4, wherein the communication interface comprises a 802.11 wireless card, which card is adapted to transmit an SSID, the trailer identifier comprising the SSTD.
6. A tyre pressure monitoring system substantially as described herein with reference to and as illustrated in the accompanying drawings.