WO2010063345A1

WO2010063345A1 - Breakout system and breakout box for measuring signals in a vehicle

Info

Publication number: WO2010063345A1
Application number: PCT/EP2009/007426
Authority: WO
Inventors: Nicola Timoncini; Riccardo Graglia; Mirco Brero
Original assignee: Gm Global Technology Operations, Inc.
Priority date: 2008-12-05
Filing date: 2009-10-16
Publication date: 2010-06-10
Also published as: GB0822195D0; GB2466001A

Abstract

Breakout system for a vehicle adapted to measure signals exchanged between a on-board system under test (4; 4a) and an electronic control unit (2; 2a). The system comprises a breakout box (1; 1a) having first connecting devices (10; 10a) for connecting the box (1; 1a) to corresponding connecting devices (8; 8a) of the electronic control unit (2; 2a) and second connecting devices (16; 16a) for connecting the box (1; 1a) to corresponding connecting devices (14; 14a) of the system under test (4; 4a). The breakout system is characterized in that it further comprises first interfacing devices (18), separated from the breakout box (1; 1a) and adapted to be coupled to said first connecting devices (10; 10a) of the box (1; 1a), said first interface devices (18) having first connecting elements (22) with the connecting devices (8; 8a) of the electronic control unit (2; 2a). The system further comprises second interfacing devices (20), separated from the breakout box (1; 1a) and adapted to be coupled to said second connecting devices (16; 16a) of the box (1; 1a), said second interfacing devices (20) having second connecting elements (26) with the connecting devices (14; 14a) of the system under test (4; 4a).

Description

Breakout system and breakout box for measuring signals in a vehicle

The present invention relates to breakout boxes used to measure signals exchanged between an engine or an on-board system and an electronic control unit of a vehicle.

The development of electronic control units for automotive application requires measurement on input/output pins of the unit itself while it is connected to an equipment under test, like simulated or actual loads, hardware-in-the-loop simulators or the engine in a vehicle. The electronic control unit pins are attached to the wiring harness of the equipment under test or the engine and thus they are not accessible; therefore, it is necessary to design a connection-breaking system, the so called breakout box, which introduces measurement points to tap-off signals between the electronic control unit and the equipment under test, while maintaining the electronic control unit connected to the equipment under test or the engine through the wiring harness. The breakout box shall not interfere with the electronic control unit operations and provide comfortable access to signals. The electrical properties of the connections between the wiring harness and the breakout box should be strictly controlled, thus allowing sufficient precision in measurement operations.

In Figure 1 a typical breakout box 1 is shown. The connections between the breakout box 1 and an electronic control unit (ECU) 2 on a first side and an engine or system under test 4 on a second side are hard-wired: a first wiring harness 6 connects pins 8 of the ECU 2 to first pins 10 of the box 1, while a second wiring harness 12 connects pins 14 of the engine or system under test 4 to second pins 16 of the box 1. Said first pins 10 and second pins 16 are constrained to the design of the pins 8 of the ECU 2 and pins 14 of the engine 4, respectively.

The breakout box 1 comprises medium current jumpers for measuring low and medium current signals.

The drawbacks of such architecture is that if said pins 8 of the ECU 2 or pins 14 of the engine 4 are changed, for example for a change in the design of the electronic control unit 2 , or if the breakout box 1 is used in another system, the breakout box 1 must be redesigned. This leads to waste a huge amount of time and resources, does not guarantee that the result will be compliant with new measurement requirements. Moreover, the new design is not reversible without wasting again the same amount of time and resources. Thus, when developing a system with new connections, the time and resources required for developing a new breakout box can badly impact the project.

Furthermore, the breakout box comprises only one type of jumpers which must be adapted to different signals, and which can not be used for high current signals.

In view of the above, it is an object of the present invention to provide an alternative breakout system which is reusable along the development of a project, which supports changes in connector shape and pin assignment and which supports also high current signals.

These and other objects are achieved according to the present invention by the breakout system of claim 1 and the breakout box of claim 6.

Particular embodiments are the subject of the dependent claims, whose content is to be understood as integral or integrating part of the present description.

Further characteristics and advantages of the invention will become apparent from the following description, provided merely by way of a non-limiting example, with reference to the accompanying drawing, in which: figure 1, which has already been described, is a schematic representation of a breakout system including a breakout box of the prior art; figure 2 is a schematic representation of a system including a breakout box according to the invention; and figure 3 is a schematic representation of a layout of a breakout box according to the invention.

Figure 2 shows a breakout box Ia connected to a first external connecting box 18 and to a second external connecting box 20. The first connecting box 18 is in turn connected to an electronic control unit (ECU) 2a while the second connecting box 20 is in turn connected to a vehicle wiring harness 4a, e.g. from the engine of the vehicle or other system under test.

The first connecting box 18 comprises first own pins 22 matching corresponding pins 8a on the control unit 2a and comprises also a wiring harness 24 matching first pins 10a on the breakout box Ia.

The second connecting box 20 comprises second own pins 26 matching corresponding pins 14a on the engine 4a and comprises also a wiring harness 28 matching second pins 16a on the breakout box Ia.

By way of example, the connecting boxes 18, 20 are depicted as having a different number of connecting elements (pins, wiring harness) according to the part of the system to which they are intended to be coupled.

Figure 3 shows a layout of the breakout box Ia. The box Ia comprises a base and a plurality of low current jumpers 60 for measuring low current signals, a plurality of medium current jumpers 62 for measuring medium current signals and a plurality of high current jumpers 64 for measuring high current signals on the base.

The current jumpers 60, 62, 64 are o a per se known type and they are preferably grouped in ranks so that this design allows a more compact packaging, a larger overall number of jumpers and supports high current paths.

Yhe base has free portions in proximity of the jumpers adapted to receive removable labels 66 so as to mark each signal with the actual name assigned to it in the system under development.

Advantageously, when using the breakout box Ia in a different system, first and second connecting boxes 18 and 20 may be changed so as to connect the breakout box Ia with the new system, and the labels 66 may be easily substituted so as to correctly identify the new signals under measurements.

To achieve a compact layout, the routing of low current signals is carried out within a printed circuit board (PCB) : this allows to get a reduction of series resistance, improving the performance of the breakout box Ia, due to the reduced impact on electrical parameters of the system to analyze. High current signals routing is kept separated from low and medium current signals and it is carried out with wires: this makes easy the handling of high currents while limiting the noise on low current signals due to high current flows.

The breakout box Ia is insulated, therefore allowing to place it on metal tables or inside the hood for in-vehicle measurement, without risking short circuits. Power signals are protected by fuses in a known manner, so protecting the control unit 2a and a vehicle fuses box which is conventionally present on the vehicle.

Clearly, the principle of the invention remaining the same, the embodiments and the details of production can be varied considerably from what has been described and illustrated purely by way of non-limiting example, without departing from the scope of protection of the present invention as defined by the attached claims.

Claims

1. Breakout system for a vehicle adapted to measure signals exchanged between a on-board system under test (4; 4a) and an electronic control unit (2; 2a), the system comprising:

- a breakout box (1; Ia) having first connecting means (10; 10a) for connecting the box (1; Ia) to corresponding connecting means (8; 8a) of the electronic control unit (2; 2a) and second connecting means (16; 16a) for connecting the box (1; Ia) to corresponding connecting means (14; 14a) of the system under test (4; 4a); said breakout system being characterized in that it further comprises first interfacing means (18), separated from the breakout box (1; Ia) and adapted to be coupled to said first connecting means (10; 10a) of the box (1; Ia), said first interface means (18) having first connecting elements (22) with the connecting means (8; 8a) of the electronic control unit (2; 2a) ; and second interfacing means (20), separated from the breakout box (1; Ia) and adapted to be coupled to said second connecting means (16; 16a) of the box (1; Ia), said second interfacing means (20) having second connecting elements (26) with the connecting means (14; 14a) of the system under test (4; 4a) .

2. Breakout system according to claim 1, wherein the first interfacing means (18) is adapted to be coupled to said first connecting means (10; 10a) through a first wiring harness (24) .

3. Breakout system according to claim 1 or 2, wherein the second interfacing means (20) is adapted to be coupled to said second connecting means (16; 16a) through a second wiring harness (28) .

4. Breakout system according to any of the preceding claims, wherein said breakout box (1; Ia) comprises a plurality low current jumpers (60) for measuring low current signals, a plurality of medium current jumpers (62) for measuring medium current signals and a plurality of high current jumpers (64) for measuring high current signals.

5. Breakout system according to claim 4, wherein the breakout box (1; Ia) further comprises at least a label (66) placed near said jumpers (60, 62, 64) for marking a corresponding signal.

6. Breakout box (1; Ia) for measuring signals exchanged between a on-board system under test (4; 4a) and an electronic control unit (2; 2a), the breakout box (1; Ia) having first connecting means (10; 10a) for connecting the box (1; Ia) to corresponding connecting means (8; 8a) of the electronic control unit (2; 2a) and second connecting means (16; 16a) for connecting the box (1; Ia) to corresponding connecting means (14; 14a) of the system under test (4; 4a); said breakout box (1; Ia) being characterized in that it further comprises a plurality of low current jumpers (60) for measuring low current signals, a plurality of medium current jumpers (62) for measuring medium current signals and a plurality of high current jumpers (64) for measuring high current signals.

7. Breakout box (1; Ia) according to claim 1, further comprising at least a label (66) placed near said jumpers (60, 62, 64) for marking a corresponding signal.