GB2339482A - Engine controller with random wiring connections - Google Patents

Description

2339482 A Vehicle This invention relates to vehicles and in particular to

a vehicle which includes an engine under the control of an engine controller.

It is becoming increasingly common to provide electronic immobilisation of the engine of a vehicle and to include such electronic immobilisation in an engine controller. In an attempt to bypass this security feature, a car thief might well take a replacement electronic controller of their own to replace to the electronic controller on the vehicle.

It is an object of this invention to provide an improved vehicle.

According to the invention there is provided a vehicle comprising an engine under the control of a controller, the controller being arranged in use to communicate with one or more sensors and actuators of the engine and to control the operation of the engine at least in part from that communication, wherein the connection of control lines between the controller and one or more of the sensors or actuators is randomly made and the controller is arranged in use to configure itself to the routing of the control lines in order to communicate with said sensors and actuators.

The controller may be arranged to perform a sequence of operations and to monitor the results of those operations to obtain feedback information as to the routing of the control lines. The controller may be arranged to memorise the routing of the control lines.

Upon an incorrect response to said sequence of operations, the controller may be arranged to disable one or more functions of the engine so that the engine cannot be started. The controller may be reset and the or each function may remain in a disabled state until the controller is reset.

The engine may comprise a spark ignition engine and the actuators may comprise spark plugs of said engine and the sensor may comprise a knock sensor, the controller being arranged to configure itself by fuelling at least one cylinder of the engine and by providing an ignition pulse to each spark plug in turn, until the knock sensor detects a signal corresponding to ignition in said cylinder.

The actuator may alternatively comprise a throttle valve motor arranged to move a throttle valve of the engine and the sensor may comprise a throttle position sensor arranged to provide feedback to the controller of the position of said throttle valve, wherein the random connection is made between the controller and the throttle valve motor and the controller is configured to the routing of the control lines making said connection by sending a sequence of instructions to the throttle valve motor and monitoring feedback of the movement of said throttle valve motor in response to said instructions.

The connection may be randomly made during manufacture of the vehicle by a random connection of wiring.

The controller may be configured to the routing of the or each control line by programming the controller using a programming means such that the controller determines the actual routing of the control lines and alters its internal logic in order to connect the control lines in a predetermined manner in response to said actual routing.

The vehicle may further comprise a limp home facility in which the controller is arranged to communicate with another control unit of the vehicle in order to establish that it is the correct controller for the vehicle and thereafter not to disable any functions of the vehicle, so that in the event of a failure of one or more systems of the vehicle a user may still operate the vehicle to the extent that it has only partially failed.

The invention also provides an engine controller for a vehicle according to the invention.

The invention will now be described by way of example with reference to the accompanying drawing, in which:

Figure 1 is a schematic diagram of a vehicle according to the invention.

Referring to the figure, a vehicle -10 includes an engine 12 whose operation is controlled by an associated engine controller 14. The engine controller 14 controls the operation of a throttle valve motor 16 to move a throttle valve 18 to control the volume of air entering an inlet manifold 20 of the engine 12. The controller 14 also provides the low tension drive to a spark ignition circuit 24.

The controller 14 operates under closed loop feedback control and is supplied with information about the position of the throttle valve 18 by a throttle potentiometer 22 and information about the performance of the ignition circuit 24 from the signals detected by a knock sensor 26.

The drive to the motor 16 is provided on a number of output lines a, b, 15 c, d from the engine controller 14. The motor 16 has a series of inputs A, B, C, D which correspond to the outputs a, b, c, d of the controller 14.

In similar fashion a series of outputs comprising a set of ignition system low tension control lines w, x, y, z from the engine controller 14 are connected to a corresponding set of inputs W, X, Y, Z of the ignition circuit 24.

During manufacture of the vehicle 10, the wires forming the control lines from the controller 14 to the motor 16 and to the ignition circuit 24 are crossed randomly so that the connection is randomly made and therefore scrambled. For example, in Figure 1 the connection from the controller 14 to the motor 16 is made aD, bA, cC, dB and the connection from the controller 14 to the ignition circuit 24 is made wX, xY, yW, zZ.

When the vehicle 10 is initially manufactured, a programming means (not shown) is used to cause the controller 14 to configure itself to the particular and random routing of the control lines in order for it to communicate with the motor 16 and the ignition circuit 24 and thereby to control operation of the engine 12. The self-configuration is achieved by altering logic connections to the outputs a, b, c, d, w, x, y, z so that the control lines are re-routed inside the controller 14 in order to achieve an effective connection of aA, bB, X, dD and wW, xX, yY, zZ regardless of the physical connection in the wiring between the controller 14 and the actuators 16, 24.

In order to unscramble the wiring and to configure itself to the desired routing of the control lines, the controller 14 is arranged to perform a sequence of operations and to monitor the results of those operations to obtain feedback information as to the scrambled routing of the control lines.

The controller 14 is arranged to output a known series of instructions along its throttle valve motor output lines a, b, c, d. The throttle potentiometer 22 provides feedback information about the movement of the throttle valve 18 and thereby feedback information about the movement of the motor 16. By outputting a series of motor drive instructions, the controller 14 can use the feedback from the potentiometer 22 to derive the physical routing of the control lines despite their random connections and then memorises that arrangement so that it can internally rearrange the routing to the correct arrangement aA, bB, cC, dD for future operation.

To derive the particular routing of the wiring forming the ignition control lines w, x, y, z, the controller 14 is arranged to provide fuelling for one known cylinder and an ignition pulse is sent down each of the ignition control lines w, x, y, z. The knock sensor 26 provides feedback to the engine controller 14 when the cylinder has achieved ignition and in this manner, by indexing through the cylinders and the ignition lines w, x, y, z, the controller 14 can derive the physical routing of those ignition lines and internally rearrange its logic to match the routing to the correct arrangement wW, xX, yY, zZ, memorising the rearranged routing for future operation.

The controller 14 is arranged to disable itself by turning off all outputs a, b, c, d, w, x, y, z in the event that there is a later mismatch amongst the control lines when the controller 14 is powered-up from a turned-off condition. The controller 14 can be reset by a programming means (not shown) and, once disabled under the above described circumstances, the controller 14 is arranged to remain in a disabled state until it is reset. In this way, when a controller which has not been configured to the vehicle 10 is used, the chance of a mismatch is greatly increased and after such a mismatch the mismatched controller is less useful to a potential thief. For example, for the eight lines illustrated above the chance of a mismatch for the control lines to the throttle valve motor 16 and ignition circuit 24 is 23 out of 24 for each case. In this manner a thief would have to carry a large number of engine controllers in order to stand a reasonable chance of stealing the vehicle 10 and thus security is improved.

To cover the case of a genuine fault, so that it does not cause a mismatch and complete disabling of the vehicle 10, a limp home mode is provided. In this manner, if the engine controller 14 is able to communicate with other controllers (not shown) on the vehicle network and is able to confirm its vehicle identification number (VIN), the failure of a vehicle network function or a controller 14 function will not render the vehicle 10 inoperative. For example, if there is a break on the line zZ, it is still possible for the vehicle to limp home on three cylinders, rather than automatically declaring a mismatch and shutting down completely.

The random connection of wiring could be extended to one or more further circuits under the control of the controller 14 and could include scrambling the wiring to one or more sensors. For example, in a vehicle including a camshaft sensor and a crankshaft sensor, the wiring to the crankshaft sensor could be scrambled and the wiring to the camshaft sensor kept constant between vehicles. In this manner, a signal from the camshaft sensor could be used to start the engine under a limp-home facility supported by the camshaft sensor which is normally only used in the event of a crankshaft sensor failure. This allows the controller to unscramble the correct wiring sequence to the crankshaft sensor under the direction of a diagnostic aid temporarily connected during manufacture of the vehicle or during servicing by an approved agent. A replacement controller could not then be satisfactorily fitted as it would not be able to synchronise its operation beyond the limp home facility provided by the camshaft sensor.

Claims (12)

1. A vehicle comprising an engine under the control of a controller, the controller being arranged in use to communicate with one or more sensors and actuators of the engine and to control the operation of the engine at least in part from that communication, wherein the connection of control lines between the controller and one or more of the sensors or actuators is randomly made and the controller is arranged in use to configure itself to the routing of the control lines in order to communicate with said sensors and actuators.

2. A vehicle according to Claim 1, wherein the controller is arranged to perform a sequence of operations and to monitor the results of those operations to obtain feedback information as to the routing of the control lines.

3. A vehicle according to Claim 2, wherein the controller is arranged to memorise the routing of the control lines.

4. A vehicle according to Claim 2 wherein, upon an incorrect response to said sequence of operations, the controller is arranged to disable one or more functions of the engine so that the engine cannot be started.

5. A vehicle according to Claim 4, wherein the controller can be reset and the or each function remains in a disabled state until the controller is resqt.

6. A vehicle according to any preceding claim, the engine comprising a spark ignition engine and wherein the actuators comprise spark plugs of said engine and the sensor comprises a knock sensor, the controller being arranged to configure itself by fuelling at least one cylinder of the engine and by providing an ignition pulse to each spark plug in turn, until the knock sensor detects a signal corresponding to ignition in said cylinder.

7. A vehicle according to any one of Claims 1 to 5, the actuator comprising a throttle valve motor arranged to move a throttle valve of the engine and the sensor comprising a throttle position sensor arranged to provide feedback to the controller of the position of said throttle valve, wherein the random connection is made between the controller and the throttle valve motor and the controller is configured to the routing of the control lines making said connection by a sequence of instructions to the throttle valve motor and feedback of the movement of said throttle valve motor in response to said instructions.

8. A vehicle according to any preceding claim, wherein the connection is randomly made during manufacture of the vehicle by a random connection of wiring.

9 A vehicle according to any preceding claim, wherein the controller is configured to the routing of the control -lines by programming the controller using a programming means such that the controller determines the actual routing of the control lines and alters its internal logic in order to connect the control lines in a predetermined manner in response to said actual routing.

10. A vehicle according to Claim 4 or any other claim when dependent thereon, further comprising a limp home facility in which the controller is arranged to communicate with another control unit of the vehicle in order to establish that it is the correct controller for the vehicle and thereafter not to disable any functions of the vehicle, so that in the event of a failure of one or more systems of the vehicle a user may still operate the vehicle to the extent that it has only partially failed.

11. A vehicle substantiallk as described herein with reference to the accompanying drawing.

12. Aja engine controller for a vehicle according to any preceding claim.