Truck trailer interface

Abstract

A pneumatic brake system for a towing vehicle and a towed vehicle wherein the brake system comprises means for providing a supply pressure and means for providing a control pressure to the towed vehicle; an electrical connection is provided between respective ECUs on the towing vehicle and the towed vehicle, the ECUs being capable of exchanging information and determining whether brake systems in both the towed vehicle and the towing vehicle are compatible with electronic brake signals and whether the brake systems are compatible with secondary supply pressure applied via a control pressure line. If both conditions are met, the braking system actuates one or more switching devices on the towing vehicle and the towed vehicle to direct air from the device for providing the control pressure to a second pneumatic supply circuit of the towed vehicle.

Description

Technical Field

[0001] The present invention relates to a pneumatic interface between a trailer and a tractor, and in particular, but not exclusively, to an interface between a heavy truck and a trailer. Background Art

[0002] As motor vehicles move towards highly automated driving, their digitalization and automation levels continue to increase, and functions traditionally performed by the driver are at least partially replaced by vehicle automation systems. This automation requires the integration of additional functions, sensors, and other electrical subsystems. It is expected that as vehicles become automated, the acceptance or tolerance of road traffic accidents by users and legislators will decrease significantly, as road deaths and injuries caused by machines are less acceptable than driver errors.

[0003] Furthermore, as the value of trailers increases, trailer availability becomes more critical to operators, which means there is pressure to improve safety levels, ensure availability and performance of key functions, and reduce error rates compared to existing vehicles.

[0004] To operate in a commercially viable manner, logistics operators need to be able to flexibly use trailers. The key to this flexibility is the ability to pair a trailer with virtually any tractor in the fleet. The requirements are known in the industry as compatibility and interoperability, and they cover couplings, pneumatic and electrical connectors, and communication protocols.

[0005] These requirements have hampered technological progress in these areas to some extent, as the age of vehicles in the fleet varies and all vehicles must be compatible and interoperable.

[0006] Taking the existing design of pneumatic couplings as an example, there are two couplings: a red coupling for supply pressure and a yellow coupling for brake or control pressure. The supply pressure is usually supplied by the third pneumatic circuit of the tractor, while the first and second circuits are used for the first and second brake circuits respectively. This design has proven to be very reliable all over the world. In Europe, there is a redundant form of brake pressure signal, which is also transmitted via CAN messages on the ISO7638 connector. However, there is no redundancy for the supply pressure, and a rupture, disconnection in the supply line, or a failure in the relevant pneumatic circuit of the tractor will trigger the emergency brake function. This will cause some or all wheels of the towed vehicle to brake automatically.

[0007] In the case of autonomous driving, this would force the vehicle combination to an immediate and uncontrolled stop.

[0008] A pragmatic approach would be to simply add another supply line. However, this is costly, as new vehicles require new interfaces in addition to the old interfaces if compatibility and interoperability are to be maintained. Similar interface attachments have been introduced in Europe in the past, such as dual auto connectors, but low installation rates indicate that the market is price sensitive. Summary of the invention

[0009] The present invention is therefore directed to providing redundancy for the pneumatic supply line from the truck to the trailer.

[0010] According to a first aspect of the present invention, there is provided an embodiment according to the features of claim 1 .

[0011] The idea of ​​the invention is to use the two existing pneumatic couplings to provide a redundant pneumatic supply from two independent circuits of the tractor. This is not only applicable to the connection between a truck and a trailer, but more generally to the connection between a tractor (which can also be a trailer in a multiple trailer or road train combination) and a towed vehicle.

[0012] Preferred aspects are stated in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0014] · Figure 1 The head plate of a semi-trailer is schematically shown;

[0015] · Figure 2 A first embodiment of a pneumatic connection between a tractor and a towed vehicle is shown;

[0016] · Figure 3 A second embodiment of the pneumatic connection between the towing vehicle and the towed vehicle is shown;

[0017] · Figure 4 A third embodiment of the pneumatic connection between the towing vehicle and the towed vehicle is shown;

[0018] · Figure 5 Another embodiment is shown having multiple electrical connections. DETAILED DESCRIPTION

[0019] Figure 1 The schematic diagram shows a semitrailer head panel in accordance with European standards, which has a red line pneumatic connection 1 for emergency brake and a yellow line pneumatic connection 2 for service brake. Four electrical connectors are arranged between the pneumatic connections, namely a 15-pin ISO12098 connector 3 with CAN bus, a 7-pin ISO7638-01 connector 4 for EBS function, a 7-pin ISO1185 connector 5 and a 7-pin ISO3731 connector 6.

[0020] Figure 2 A first exemplary embodiment is shown in which the electrical connection between the tractor vehicle and the towed vehicle can be used to transmit the brake pressure signal in digital or analog form.

[0021] exist Figure 2 In the embodiment of FIG. 1 , the tractor is shown as a truck, and its braking system is shown schematically. The truck braking system includes a compressor 20 connected to an air handling unit 21, which provides air to first and second air tanks 22, 23. The outlet of each air tank 22, 23 is pneumatically connected to a foot brake valve 24 and provides supply pressure for the first and second brake circuits on the truck. The air handling unit 21 is also connected to a third air tank, the output of which is connected to a trailer control module 25. The trailer control module receives inputs from the first and second brake circuits and is pneumatically connected to the trailer via a (red) supply line 26.

[0022] The trailer control module 25 is also pneumatically connected to a solenoid valve 27, providing a (yellow) control line pressure connection 28 to the trailer. The solenoid valve 27 receives a further pneumatic input from the air tank 22. The ECU 29 is arranged to control the operation of the solenoid valve 27 and receives an electrical signal on line 30.

[0023] Also schematically shown is a trailer brake system with a trailer brake module 40 which receives supply pressure from a first trailer air tank 41 via line 26. The trailer brake module 40 also receives electrical signals on line 30 which is connected to the truck via a connector 32 conforming to a standard.

[0024] A solenoid valve 42 is provided which is controlled by an ECU 43 which receives a control signal from the trailer brake module via line 44. The solenoid valve is pneumatically connected to the control line 28 and has a control line 45 and a supply line 36 output to the trailer brake module. A further air reservoir 47 is also provided in line 36.

[0025] The presence of an electrical signal on line 30 means that the brake pressure signal on the yellow coupling 28 is redundant. In this case, the pneumatic connection can be used to provide a second air supply to the brake system of the trailer or towed vehicle. In the towing vehicle, the ECU 29 is connected to the ECU 43 in the towed vehicle. The two ECUs can exchange information and determine:

[0026] a. Are the brake systems of both vehicles compatible with electronic brake signals?

[0027] b. Is the vehicle compatible with receiving / providing auxiliary supply pressure via the yellow coupling?

[0028] If the answer to both questions is yes, the vehicle can activate the pneumatic switching device:

[0029] Provide air supply from brake circuit supply 1 or 2 to the yellow coupling in the towing vehicle;

[0030] Redirect the air from the yellow coupling to the second pneumatic circuit of the towed vehicle.

[0031] Figure 2 The ECU in the control system can be an independent ECU, or its functions can be integrated into the brake system ECU, vehicle control ECU or other existing ECUs of the towed / traction vehicle.

[0032] exist Figure 3 In the drawings, the same reference numerals are used for the same parts. In the present embodiment, the supply of the valve 27 can be switched between the first and second brake circuits. The switching device is shown as a selector valve 31, such as a high selector valve or a double check valve. However, it can be any type of valve or redirection mechanism for the above-mentioned purpose. Figure 2 Similar to the embodiment of the present invention, when a fault occurs or other situations occur where the yellow coupling head needs to transmit a brake pressure signal, the switching mechanism can be restored to the default position, so that the yellow coupling head on the tractor is connected to the brake pressure signal from the brake system again, and the coupling head on the towed vehicle is connected to the brake system.

[0033] The difference between this embodiment and the first embodiment is that the pneumatic supply is supplied to the yellow coupling head. In this embodiment, at least two pneumatic supply circuits are used, and the two pneumatic supply circuits are combined with the high-select valve. Figure 3 The case where the brake circuit supplies two circuits 1 and 2 is shown, but additional circuits can also be used. The high selector valve can be used either in cascade or in an integrated version to support more inputs.

[0034] Figure 4 Another embodiment is shown in which the brake pressure comes from multiple supply circuits via a 2 / 3-way valve 35. This embodiment also uses multiple supply circuits to feed the yellow coupling head. The main difference from the second embodiment is that the supply source can be actively selected using information collected by the towing vehicle and / or information received from the towing vehicle. The selection can be done by ECU 29 or another ECU connected thereto. Figure 4 In the embodiment, the selector valve is an electrically controlled two-position three-way valve. It can be any other valve or device used for this purpose.

[0035] Figures 2 to 4 The selection / switching device shown can be an independent component as shown in the figure, or it can be integrated into an existing component, such as a trailer control module of the tractor or a braking system of the tractor / towed vehicle.

[0036] Figure 5Another embodiment is shown having a plurality of electrical connections for facilitating communication between ECUs in the towing and towed vehicles. Figure 5 The case of a first embodiment is shown, but it is compatible with all design variants.

[0037] In each case, in a first mode of operation, when the trailer is connected to the truck and the truck ignition is switched on, the ECU 29 or equivalent checks whether the corresponding capability is available on the trailer. In this mode, once it is determined that the two vehicles are compatible, the supply will switch to the redundant supply mode; if a fault is detected that makes the towed / tractor vehicle incompatible with the redundant supply, the supply will switch back to the normal mode.

[0038] The alternate mode defaults to normal mode and switches the control pressure to supply pressure only if a failure of the main supply on the red coupling is detected.

[0039] Currently, the valid standards are ISO1185:2003, ISO7638-1 / 2:2018, ISO11992:2021, ISO12098:2020 and SAE560:2020.

Claims

1. A pneumatic braking system for a tractor and a towed vehicle, wherein: The brake system includes a device for providing a supply pressure and a device for providing a control pressure to the towed vehicle; wherein an electrical connection is provided between the towing vehicle and the towed vehicle, and each of the towing vehicle and the towed vehicle is equipped with a corresponding ECU; the ECU is capable of exchanging information and determining a first condition: whether the brake systems in the towed vehicle and the towing vehicle are both compatible with electronic brake signals; and a second condition: whether the brake system is compatible with the auxiliary supply pressure applied via the device for providing a control pressure; when both conditions are met, the brake system actuates one or more switching devices to direct air from the device for providing a control pressure to a second pneumatic supply circuit of the towed vehicle.

2. The pneumatic brake system according to claim 1, wherein: The device for providing a control pressure is switchable so as to receive a brake pressure signal or supply pressure from a brake system of the towed vehicle.

3. The pneumatic brake system according to claim 1 or 2, wherein: The switching device is an electrically or pneumatically controllable two-position three-way valve.

4. The pneumatic brake system according to claim 1, wherein: The pressure is supplied from multiple supply circuits via selector valves.

5. The pneumatic brake system according to claim 4, wherein: The supply source can be actively selected using information collected by the towed vehicle and / or information received from the towing vehicle.

6. The pneumatic brake system according to any one of claims 1 to 5, wherein: When the trailer is connected to the truck and the truck ignition is turned on, the ECU on the tractor checks whether the towed vehicle has the corresponding capability.

7. The pneumatic brake system according to claim 6, wherein: When it is determined that the towed vehicle and the towing vehicle are compatible, the supply pressure is switched.

8. The pneumatic brake system according to claim 7, wherein: The supply pressure is switched only when a failure of the main supply is detected.

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