NZ779350A - Brake controller with a housing or a loom - Google Patents

Abstract

The present invention relates to a brake controller for a towed vehicle braking system, with a housing or a loom, and including one or more input connectors for electrical connection to a towing vehicle and an output connector for electrical connection to a towed vehicle.

Description

Brake controller with a housing or a loom Technical Field The present invention relates to a brake controller for a towed vehicle braking system. The brake ller includes a housing or a loom including one or more input connectors for electrical connection to a towing vehicle and an output connector for electrical connection to a towed vehicle.

Background of Invention Towed vehicles such as trailers of various classes have different braking systems. Commonly, rs with weights n 750kg and 4.5 tons have electromagnetic braking systems or hydraulic braking systems controlled by electromagnetic actuators. For both of these systems, braking of the trailer is controlled by an ical signal from a towing vehicle.

Brake controllers may be used to generate the electrical signal to better control operation of the towed vehicles braking systems. For example, an existing type of brake controller is mounted in the towing vehicle and hardwired into the towing vehicle wiring system so as to receive a g signal from the towing vehicle and to uently generate an electrical signal instructing the operation of the brakes of the towed vehicle. In another e, another type of existing brake controller is d in the towing e and employs a microprocessor and an accelerometer to determine deceleration of the towing vehicle. This brake controller then generates an electrical signal instructing the operation of the brakes of the towed vehicle based on the deceleration.

It is, however, not always desirable to mount a brake ller in a cabin or engine bay of a towing vehicle – especially where the interior trim of the towing e may be damaged. It may be desirable, for example, to provide a more versatile brake controller that can be mounted on exterior to the towing vehicle or the towed vehicle. However, mounting a brake controller in such a way may cause nges to arise as, for example, the accelerometer may need to be mounted in a particular position and orientation relative to the towing vehicle, and the accelerometer and other components of the brake controller need a readily accessible power supply. Allowing control by the driver is another challenge.

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that nt or matter was known or that the information it contains was part of the common general dge in Australia or ere as at the priority date of any of the disclosure or claims herein.

Such discussion of prior art in this specification is included to explain the context of the present invention in terms of the or’s dge and experience.

Summary of Invention According to one aspect, there is provided a brake controller for a towed vehicle braking system, said brake controller adapted to generate a braking control signal to the towed vehicle braking system, the brake controller including: an inertial sensor including plural sensor axes for generating sensor data associated with each sensor axis; a processor for processing said sensor data to te a deceleration of the towing vehicle; and a housing including an input connector for ical connection to a towing e and an output connector for electrical connection to a towed vehicle, wherein the inertial sensor and the processor are housed within the housing, and the brake controller is electrically connected to the towing vehicle via the input tor and to the towed vehicle via the output connector, and wherein the brake controller including the inertial sensor and the processor receive power from the towing vehicle, whereby the brake ller is adapted to generate and output the braking control signal to control activation of brakes of the towed e braking system based on the deceleration of the towing vehicle estimated by the processor and a brake light signal received by the processor from the towing vehicle via the input connector.

In an embodiment, the brake controller is integrated into AS4471 tor types or AS2513 tor types. Preferably, the brake controller is compatible with chemical encapsulation processes, thereby avoiding the need to provide a sealed housing.

In an embodiment, the input connector includes an input plug adapted to be received in a socket of the towing vehicle thereby electrically and mechanically connecting the brake controller to the towing vehicle, and the output connector includes an output socket adapted to receive a plug connected to the towed vehicle.

In addition, or alternatively, the brake controller is configured to be mechanically connected to the towing vehicle with a captive fixing mechanism of the vehicle to encourage the user to install correctly. In an example, the input plug is a 12-pin plug, such as an AS4471 12-pin plug, the socket of the towing vehicle is a 12-pin , the output socket is a 12-pin socket and the plug connected the towed vehicle is a 12- pin plug. Also, it is likely that the brake controller would be used with an extension/adapter cable, as commonly done in the lian market, to convert from a round to a flat 12-pin plug/socket.

In an embodiment, the brake controller is formed in a socket of the towing vehicle. Alternatively, the brake controller is formed in a plug adapted to be received in a socket of the towing vehicle. The brake controller is therefore packaged in such a way as to be shared between towing vehicles and towed vehicles, such as rs.

As mentioned, in one embodiment, the housing of the brake controller houses the onics of the brake controller within a modified Australian 12-pin trailer connector and has the ability to sense vehicle braking via an inertial sensor or accelerometer and via the brake light signal from the towing e.

In a r embodiment, the brake controller may be designed as a housing with an attached loom for installation with the towbar of the towing vehicle.

In an embodiment, the brake controller is configured to receive power from the towing vehicle via the input connector. Alternatively, the housing includes a further input connector, and the further input connector is d to receive power from the towing vehicle. In both embodiments, the brake controller is configured to supply operating power to the towed vehicle braking system via the output connector from the power received from the towing vehicle.

In another ment, the input connector is adapted to t to an r loom that is adapted to e the power and the brake light signal from the towing vehicle. The adapter loom may include a first adapter connector adapted to receive the brake light signal from the towing vehicle and a second adapter connector adapted to receive the power from the towing vehicle.

As not all Australian connectors have a power feed, alternative implementations are presented with the ability to draw power from lighting circuits or from al power connections. For example, on many vehicles, a direct power supply is not available, and thus embodiments of the brake controller are provided to draw power from lighting circuits. The amount of power ed from each lighting circuit may be regulated, and the regulated amount of power may be configured by the user.

More specifically, in an embodiment, the brake controller further includes a power tap circuit d to supply operating power to the towed vehicle g system from the brake light signal received from the towing vehicle via the input connector and or from a tail light signal received from the towing vehicle via the input connector. The power tap circuit includes a brake light t having at least a brake light transistor adapted to supply the operating power from the brake light signal when a threshold voltage indicative of the brake light signal being turned ON is detected as being exceeded.

In an embodiment, the power tap circuit includes a tail light circuit having at least a tail light transistor adapted to supply the power from the tail light signal when a threshold voltage indicative of the tail light signal being turned ON is detected as being exceeded.

To control the power from lighting circuits, the sor may further include a control loop adapted to determine RMS current drawn from the tail light signal and the brake light , e the RMS current with a RMS current limit, and limit the power supplied from the tail light signal and or the break light signal if the RMS current exceeds the RMS current limit.

In an embodiment, the brake controller further includes power electronics, in communication with the processor, adapted to generate and output the braking control signal to control activation of the brakes of the towed vehicle braking system.

The power tap circuit may r be adapted to supply the power for the power electronics.

In an embodiment, the brake light circuit has an ion transistor adapted to be turned OFF when the braking control signal is outputted by the power electronics to prevent the towing vehicle from detecting that brake lights of the towed vehicle are turned ON. For e, on some new vehicles, a brake controller connected to the towing vehicle wiring while a trailer is not attached must not pull the lighting circuits down below a certain level to avoid tripping towing vehicle faults.

In an embodiment, the brake controller tes the braking control signal to the towed e braking system when a threshold voltage indicative of the brake light signal being turned ON is detected as being exceeded. For example, the brake controller loads the brake light signal with a test load greater than 0.1mA, and substantially disables the test load when voltage of the brake light signal is detected as falling below the threshold voltage, in order to prevent the towing vehicle from detecting connection of the towed vehicle.

In an embodiment, the brake ller further includes s disposed between the input connector and the output connector, and the sor and the inertial sensor are implemented in a module having a d Circuit Board (PCB), wherein connections from the bus-bars terminate at the PCB. The module and the connections from the r that terminate at the PCB are also housed within the housing. Further, the connections from the busbars are pins inserted into the busbars and the connections terminate at the PCB into holes in the PCB being sized to e an interference fit with the connections, thereby providing electrical connection and mechanical support to the PCB.

According to another aspect, there is provided brake controller for a towed vehicle braking system, said brake controller d to generate a braking control signal to the towed vehicle braking system, the brake controller including: a module having an inertial sensor ing plural sensor axes for ting sensor data associated with each sensor axis and a processor for processing said sensor data to estimate a deceleration of the towing vehicle; and a loom including input connections for electrical connection to a towing vehicle and output connections for electrical connection to a towed e, wherein the brake controller is electrically ted to the towing vehicle via the input connections and to the towed vehicle via the output connections, wherein the brake controller including the inertial sensor and the processor receive power from the towing vehicle, and wherein the module is attached to the loom, and whereby the brake controller is adapted to generate and output the braking control signal to control activation of brakes of the towed vehicle braking system based on the deceleration of the towing vehicle estimated by the processor and a brake light signal received by the processor from the towing vehicle via the input connections.

In an embodiment, the processor and the inertial sensor are ented on a Printed Circuit Board (PCB) of the module, and end wires of the loom are encapsulated separately to an enclosure containing the PCB. Further, the module and at least part of the wires of the loom that terminate at the PCB are either sealed in an enclosure, over-moulded or potted, thereby providing insulation and mechanical support to the module.

Brief ption of Drawings Embodiments of the present invention will now be described with reference to the accompanying gs, wherein: Figure 1 is a block diagram showing an embodiment of a brake controller for a towed vehicle braking system; Figure 2 is a block m showing r embodiment of a brake controller for a towed e braking system; Figure 3 is a block diagram showing another embodiment of a brake controller for a towed e braking system; Figure 4 is a block diagram showing another embodiment of a brake controller for a towed vehicle braking system; Figure 5 is a block diagram showing another embodiment of a brake controller for a towed vehicle braking system; Figure 6 is a block diagram showing r embodiment of a brake ller for a towed vehicle braking system; Figure 7 is a block diagram showing an embodiment of a brake controller for a towed vehicle g system in operation; Figure 8 shows an embodiment of a brake/tail light isolation circuit and tap circuit of a brake controller; Figure 9 shows an ment of brake/tail light detection circuits of a brake controller; Figure 10 shows an embodiment of a tail light detection bias circuit of a brake controller; Figure 11 is a flow chart showing an embodiment of operation of a control loop of a brake controller; Figure 12 is a perspective view of an embodiment of a brake controller; Figure 13 is an assembly view of the brake controller of Figure 12; Figure 14 shows a fit pin being ed into a busbar of an embodiment of a brake controller; Figure 15 is a perspective view of an embodiment of an input connector of a brake controller; Figure 16 is an assembly view of an embodiment of an input tor of a brake controller; Figure 17 is a perspective view of an embodiment of a brake controller incorporated with a loom; Figure 18 is an exploded view of an embodiment of a brake controller for installation with a towbar; Figure 19 is a top view of an embodiment of a brake controller for installation with a towbar; Figure 20 is a rear view of an embodiment of a brake controller for installation with a towbar; Figure 21 shows loom details of an embodiment of a brake controller for installation with a towbar having a powered connector; and Figure 22 shows loom details of an embodiment of a brake controller for installation with a towbar having no powered tor.

Detailed Description Figure 1 shows a brake controller 10 for a towed vehicle braking system ing to an embodiment of the present invention. The brake controller 10 is electrically connected to a towing vehicle 11 and to a towed vehicle 13 to control the braking system 15 of the towed vehicle 13. To do so, the brake controller 10 is adapted to generate a braking control signal for the towed vehicle braking system 15.

The brake controller 10 further includes a g 12, and electronic components to generate the braking control signal for the towed vehicle braking system 15. The electronic components include an inertial sensor 14, including plural sensor axes for generating sensor data associated with each sensor axis, and a processor 16 for processing the sensor data to estimate a ration of the towing vehicle. The inertial sensor 14 and the processor 16 are housed within the housing 12.

The housing 12 further includes an input connector 18 for electrical connection to the towing vehicle 11 and an output connector 20 for electrical tion to the towed vehicle 13. Thus, the brake controller 10 is electrically connected to the towing vehicle 11 via the input connector 18 and to the towed vehicle 13 via the output connector 20. The brake controller 10 is also configured to e power from the towing vehicle 11 for its operation via the input tor 18.

In operation, the brake controller 10 is adapted to generate and output the braking control signal to control activation of brakes of the towed vehicle braking system 15 based on the deceleration of the towing e 11 ted by the processor 16 and based on a brake light signal of the towing vehicle 11 received by the processor 16 from the towing vehicle 11 via the input connector 18.

The g control signal can communicate further information to the braking system 15 of the towed vehicle 13, including an output level that is used to control a braking force to be applied to the brakes of the towed vehicle braking system 15. A user can control the output level by controlling the gain for the braking control signal with a remote head 17 associated with the brake controller 10, as shown in Figure 2. The remote head 17 is mounted in the towing vehicle 11, remote from the brake controller 10, and is configured to control the gain for the braking control signal. The remote head 17 may be potentiometer configured to provide gain control or a rotary encoder. Also, the remote head 17 may include other input and output devices so that a user can interface with the brake controller 10, such as a touch screen y or LEDs to display status of the braking system 15.

The remote head 17 may be configured to wirelessly communicate with the brake controller 10 to control the brake controller 10. The remote control may instead be achieved by an application implemented by a computer or smart phone. The remote control may allow a per-vehicle setting for t that may safely be drawn from lighting circuits. Also, the remote control (or application) allows for reporting of warnings when power requirements of the brake controller 10 exceed (or are likely to exceed) the rated power of the supply.

The inertial sensor 14 may also take the form of an accelerometer configured to determine deceleration of the towing vehicle 11. Such an accelerometer is a multi-axis accelerometer for sensing the deceleration of the towing vehicle 11 in multiple directional axes in order to ensure that acceleration can be transformed so that braking deceleration may be ted from other signals. The processor 16 is ured in this embodiment to generate the braking control signal to control activation of the brakes of the towed vehicle braking system 15 based on the determined deceleration of the towing vehicle 11 and the received brake light signal from the towing vehicle 11. The electrical control signals will then be amplified by power electronics of the braking system 15 to control the mechanical components of the braking system 15 via suitable electromagnetic, hydraulic or pneumatic ors. The power electronics may include high-side s and commutating diodes in order to drive the electromagnetic ors, which are commonly highly inductive and e high t.

It will be appreciated by those persons skilled in the art that the processor 16 ents program code to operate the brake controller 10. The program code could be supplied in a number of ways, such as on a memory in data communication with the processor 16. The processor 16 may also be incorporated into a microcontroller that is configured to execute one or more algorithms in the program code, stored in an associated memory, such as RAM and/or ROM (not shown), to te the braking control signal to control activation of brakes of the towed vehicle braking system 15.

The input connector 18 and output connector 20 of the brake ller 10 may also take a number of forms to suit different connector types for different towed and towing es, as exemplified in Figures 3 to 6. In these examples, the connector type is predominantly an AS4471 connector type.

The brake controller 10 is constructed with two 12-pin connectors in Figure 3. The input connector 18 mates with a 12-pin socket on the towing vehicle 11, and the output connector 20 is a 12-pin socket to which the towed vehicle 12-pin plug will t. The input connector 18 in this example is an input plug adapted to be ed in the socket of the towing vehicle 11 to electrically and mechanically connect the brake controller 10 to the towing e 11. Alternatively, the brake controller 10 has an additional connector for power as shown in Figure 4. That is, in this embodiment, the housing 12 includes a further input connector adapted to receive power from the towing vehicle 11. In both es, the brake controller 10 is configured to supply ing power to the towed vehicle braking system 15 via the output connector 20 from the power received from the towing vehicle 11.

In a further example shown in Figure 5, the brake controller 10 is supplied or installed with an adapter loom. The input tor 18 here is adapted to connect to an adapter loom that is adapted to receive the brake light signal from the towing vehicle 11 via a first adapter connector and to receive power via a second adapter connector.

In the example shown in Figure 6, the brake controller 10 is formed in a socket of the towing vehicle 11. The brake controller 10, including the electronics, here is packaged within a modified Australian 12-pin trailer connector and has the ability to sense vehicle braking via the abovementioned accelerometer and brake light signal.

In another embodiment shown in the Figure 17, the brake controller 10 is formed within one or more looms. For example, the brake controller 10 includes a module having the inertial sensor 14 and the processor 16, and a loom including the input tor 18 at one end and the output connector 20 at the opposed end of the loom. The loom, in this manner, provides the electrical connection for the brake controller 10 to the towing vehicle 11 and the towed vehicle 13. The module is disposed n the input tor 18 and the output connector 20 and is integrated with the loom. Within this module, wires of the loom ate at a circuit implemented on a Printed Circuit Board (PCB) of the module. This module could be over-moulded or potted, with wires of the loom going through the encapsulant and terminating at the PCB, thereby providing mechanical support and insulation to the module.

In another ment shown in the Figures 18 to 22, the brake controller is also formed within one or more looms and es a module having the inertial sensor 14 and the processor 16. The loom includes input connections and output connections, and the module is attached to the loom. The processor and the inertial sensor are also implemented on the Printed Circuit Board (PCB) and the ends wires of the loom are encapsulated separately to an enclosure containing the PCB.

In Figure 17, the two connectors shown are standard 12-pin connectors, but any of the other combinations of connectors from Figures 3 through 6 may be used to terminate the loom, or the loom may be left unterminated for the installer to connect. As not all towed vehicle connectors have a power feed, alternative implementations of the brake controller 10 are provided with the ability to draw power from lighting circuits or from external power connections. Figure 2 shows the g 12 containing an electrical power tap circuit 22 to draw power for the brake controller Figure 7 shows a block m of operation of the brake controller 10 shown in Figure 2. The different blocks in this Figure show how the brake controller can operate independently of the towing or towed vehicle, such as the ability to tap power from lighting circuits or from an additional connector, and employing a brake light triggering circuit to sense whether a brake light signal is received from the towing vehicle. These are discussed in more detail below.

In one embodiment, the brake controller 10 draws power from a 12V circuit on a rd Australian 12-pin tor, as per the arrangement in Figures 3, or from a separate vehicle circuit, as per the arrangement in s 4 and 5. For example, 4-wheel drive vehicles often have an “Anderson” type connector at the rear of the vehicle for auxiliary power to a r.

In another embodiment, power for the brake controller 10 is tapped from lighting ts using the power tap circuit 22. In order to maximise compatibility of this brake ller 10 with different es, it is preferable that the brake controller draw powers from lighting circuits. Such circuits, however, may have limitations.

For example, if too much current is drawn (typically > 15A), a fault may be reported or a fuse may blow. Also, if even a small amount of current (e.g. 100uA) is drawn when no trailer is attached, the vehicle may detect attachment of a trailer and disable parking sensors. Furthermore, if brake lights are lit by a brake controller, some vehicles may detect this as a wiring fault. The brake controller 10 prevents these limitations so that it may be more convenient for the driver to leave it connected to the towing vehicle 11 permanently.

The power tap circuit 22 is adapted to supply operating power to the towed vehicle braking system 15 from the brake light signal received from the towing vehicle 11 via the input tor 20 using a brake light t 24. Also, the power tap circuit 22 es operating power to the towed e braking system 15 from the tail light signal received from the towing vehicle 11 via the input connector 20 using a tail light circuit 26.

Figure 8 shows part of the brake light circuit 24 and the tail light circuit 26 in more detail. The brake light circuit 24 includes transistor Q203A adapted to supply the operating power from the brake light signal when a threshold voltage indicative of the brake light signal being turned ON is detected as being exceeded. And, the tail light circuit 26 includes a tail light transistor Q203B adapted to supply the power from the tail light signal when a threshold voltage indicative of the tail light signal being turned ON is detected as being exceeded. That is, Q203A/B of Figure 8 allow the brake controller 10 to draw power from brake and tail light inputs. The substrate diodes allow bootstrap of the system when there is no battery power on VPROT, but prevent current from being drawn by the lights when the system is powered from VPROT. When the brake controller 10 is delivering current to the brake output, Q201B and Q205B may be turned off to allow Q203 to turn on, reducing the heat production in Q203. Q200A may also be turned on. Q200A must be turned off rly, however, to allow the brake light sensing circuit to poll the brake light status.

In order to allow operation from the tail light circuit, which has a limited t capability, the brake controller 10 is configured to control RMS current draw during operation. This may be done via a Proportional/Integral (PI) control loop as shown in Figure 11 and further described below. The control loop is d to determine RMS current drawn from the tail light signal and the brake light signal, compare the RMS current with an RMS current limit, and limit the power supplied from the tail light signal and or the break light signal if the RMS current exceeds the RMS current limit. The RMS current limit for example is nominally 15A and is used as the target value for the control loop. This may further be configurable by a ss remote control of the brake controller 10, such as via the remote head 17, or by a y-set vehicle-specific g if the part is sold as an installation kit for certain vehicle types.

Current is measured by the output control switching circuit, which may be, for instance, a VN7007 from ST microelectronics. The RMS current is estimated cycle-by-cycle from the peak and/or valley current measurements. The difference between the estimated RMS current and the RMS current limit (the “error” signal) is fed to Proportional (P) and Integral (I) calculations. The proportional branch is a gain only, and the integral branch contains: a numerical integrator, a limiter on the integration value (to prevent the t from exceeding the limit for too long when the PWM control value changes), and a gain. The output of the P and I calculations are summed, and then compared with the PWM level set by the accelerometer/input calculations. The minimum value of the two is then used to control the power electronics to the brake output. When the brake ller detects that this control loop is limiting power, or is likely to limit power, it may provide a g to the driver via the wireless remote system that the power supply is not sufficient to drive the brakes safely.

The brake light circuit 24 also has an isolation transistor adapted to be turned OFF when the g control signal is outputted by the power electronics to prevent the towing vehicle from detecting that brake lights of the towed vehicle are turned ON. Figure 8 shows circuitry to prevent vehicle faults from being tripped when the brake controller activates the brake lights independently of the vehicle. When the brake controller is driving the brake light, Q200A can be turned off to prevent the vehicle from sensing the voltage produced by the brake controller. At the same time, Q201A should be turned on to prevent the vehicle sensing disconnection of the trailer and enabling reversing sensors. In a bootstrap condition, the substrate diode of Q200A will allow a trailer lighting module on the vehicle to sense that the brake light circuit of the trailer is attached.

The brake light circuit 24 and the tail light circuit 26 r include lowcurrent nce detection circuits. Many modern vehicles have trailer lighting modules that have very low thresholds for detection of lighting circuits. Any circuit that pulls the output voltage on a high-impedance lighting circuit more than around 6V below the supply voltage will cause such a tow vehicle to detect a trailer. This is undesirable because it will mean that park ance s will be ed while the circuit is attached, and it will also prevent the tow vehicle from detecting faults in lighting circuits. That is, the brake controller 10 generates the braking control signal to the towed vehicle braking system when a threshold e indicative of the brake light signal being turned ON is detected as being exceeded. In one ment, the brake controller 10 loads the brake light signal with a test load r than 0.1mA, and ntially disables the test load when voltage of the brake light signal is ed as falling below the threshold voltage, in order to prevent the towing vehicle 11 from incorrectly detecting connection of a towed vehicle (a phantom of towed vehicle 13).

Figures 9 and Figure 10 show circuits that are used to prevent such faults.

In this circuit, the voltage reference D211 gives a voltage approximately 4V below the supply voltage. This is then used as the gate voltage for the P-channel MOSFETs Q206 and Q207. This means that the light detection circuits (R231, R232, R229, R230, Q209 and Q210) cannot pull the voltage at Brake_in or Tail_in more than approximately 3V below the supply voltage. If the pull-up on the brake light circuits has a high impedance (e.g. a fault ion circuit), then Q206/Q207 will turn off, and no signal will be detected, r, if a low impedance pull-up is used (e.g. lights are switched on), then Q206/Q207 will be able to conduct detectable current to R231/R232, causing the light signal input to be detected. It will be appreciated that Q206/Q207 may be replaced by other voltage-controlled devices such as JFETs.

R231, R232, R229, R230, Q209 and Q210 may be replaced with other current to logic level conversion circuits.

Figures 12 to 16 show embodiments the brake controller 10 within the housing 12. The brake ller 10 includes busbars 30 disposed between the input connector 18 and the output connector 20. The electronics of the brake controller 10 are implemented on a Printed Circuit Board (PCB) 28, and connections 32 from the bus-bars 30 terminate at the PCB 28 at holes 34. In these embodiments, the input connector 18 and the output connector 20 include pins that are machined from the bus-bars 30 to have terminations compliant with .5.

Press-fit pins 32 are inserted into the bus-bars 30. The bus -bars 30 are then inserted into the input tor 18 and the output connector 20, and a circuit assembled onto the PCB 28 is pressed onto the pins 32, with the holes 34 in the PCB 28 being sufficiently small to provide an interference fit with the pins 32, thereby providing an ical connection and a mechanical support to the PCB 28. The PCB is conformally coated, potted or overmoulded for weather tion. The g 12, not shown in these Figures, houses the coated assembly and provides ingress protection against wires, stones, etc. (e.g. IP54 or less). In an alternative configuration, the connectors 18 and 20 of the brake controller 10 are arranged in two rows to connect with a vehicle side connector 38 of the type shown in Figures 15 and 16.

In an alternate embodiment, the rs 30 for the brake ller 10 are machined in two halves, then joined with an insulating segment 36, shown in Figure 13, with press-fit connections at each end. In combination with the circuit designs documented above, this may prevent detection of brake light or trailer brake activation by the towing vehicle 11, as such detection may cause spurious fault indications on some vehicles.

In another alternate embodiment, only the upper 7 pins would be ed, and the tor component would be compliant with the 7-pin variant of AS4177.5.

This variant may also have a separate power supply cable that may attach to the towing vehicle via the common Anderson connector type. Alternatively, it may be ed from the vehicle lighting signals via the circuitry described in this patent.

An alternate embodiment may have the bus-bars 30, moulded into a subassembly with the connectors 32 before fitting the board 28. In this t, the housing 12 may seal (IP66 or better) to the connectors 10 and 20, making coating or potting of the product unnecessary.

An alternate embodiment is shown in Figure 18 to 21, which has the brake controller 10 separate from the input and output connections, and is designed to fit to other parts of the towbar system. In this embodiment, a first 42 and a second housing 46 may be sealed together around electronics 41 using ultrasonic welding, and then connected to a loom via a d connector 44, sealed with o-rings 45 to a recess in one half of the housing 46 where the recess is provided to prevent leakage at parting or weld lines. These features enable survival of stresses seen at the towbar, such as thermal shock, stones and water immersion. The housing has a sizing 48 to fit on common, square hollow sections that are used in towbars, and s 49 to enable fixing with cable ties. The electronics may use a radio connection for control, and therefore the housing has a desired orientation relative to the towbar s.

A curvature of the outer surface 47 and a flat surface 50 may be ed to encourage installation of that face against the metal surface of the towbar elements, thereby ng that the antenna is ng outwards.

This embodiment may have a n of the loom with equal-length wires, from the connector 44 to ends terminated with ferrules 51 for easy installation to a trailer connector. The wires in this loom may be stop lamp, earth, power and brake output wires. It may further include a branch earthing element 56, such as a ring terminal sized for the bolts used in a towbar (e.g. M10). The wires to the trailer connector may be made with a thin insulation (e.g. TXL) for ease of installation. To support the brake light isolation feature, a separate wire may be ed, preterminated to a butt splice 58 with glue-lined rink for the installer’s convenience.

An alternate embodiment is shown in Figure 22 for fitment to a towbar which may have a custom loom with equal lengths of wire from the connector 44 to ends terminated with ferrules 51 for wires which go directly to an red connector (such as an Australian 7-pin trailer connector), being the stop lamp and brake output wires. For the supply wire, it may have a longer wire 52 with a fuse holder 53, suitable for routing along the e to the battery. This supply wire may be bundled in a conduit 57 with a separate supply wire for an ary power connector 54. In this case, the fuse holders for the brake controller and the auxiliary power tor may be bussed together on a bus 55 for the installer’s convenience. atively , the longer loom for the power connection may be supplied separately, together with a butt splice and glue-lined heat-shrink, to allow the installer to cut it to length.

Yet another embodiment for fitment to a towbar may have a custom loom to mate with connectors already existing on the vehicle.

Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

Claims (24)

The claims defining the invention are as follows

1. A brake controller for a towed vehicle braking , said brake controller adapted to generate a g control signal to the towed vehicle g system, the 5 brake ller including: an inertial sensor including plural sensor axes for generating sensor data ated with each sensor axis; a processor for processing said sensor data to estimate a deceleration of the towing vehicle; and 10 a housing ing an input connector for electrical connection to a towing vehicle and an output connector for electrical connection to a towed vehicle, wherein the inertial sensor and the sor are housed within the housing, and the brake controller is electrically connected to the towing vehicle via the input connector and to the towed vehicle via the output connector, and 15 wherein the brake controller including the inertial sensor and the processor receive power from the towing vehicle, whereby the brake controller is adapted to generate and output the braking control signal to control activation of brakes of the towed vehicle braking system based on the ration of the towing vehicle estimated by the processor and a 20 brake light signal received by the processor from the towing vehicle via the input connector.

2. A brake controller according to claim 1, n the brake controller is configured to receive power from the towing vehicle via the input connector.

3. A brake controller according to claim 2, wherein the input connector is d 25 to connect to an adapter loom that is adapted to receive the power and the brake light signal from the towing vehicle.

4. A brake controller according to claim 3, wherein the adapter loom includes a first adapter connector adapted to receive the brake light signal from the towing vehicle and a second adapter connector adapted to receive the power from the towing 30 vehicle.

5. A brake controller according to claim 1, wherein the housing includes a further input connector, and the further input connector is adapted to receive power from the towing vehicle.

6. A brake controller according to any one of claims 2 to 5, wherein the brake 5 controller is configured to supply ing power to the towed vehicle braking system via the output connector from the power received from the towing e.

7. A brake controller according to any one of claims 1 to 5, wherein the brake controller further es a power tap circuit adapted to supply operating power to the towed vehicle braking system from the brake light signal received from the towing 10 vehicle via the input connector and or from a tail light signal received from the towing vehicle via the input connector.

8. A brake controller according to claim 7, wherein the power tap t includes a brake light circuit having at least a brake light transistor adapted to supply the operating power from the brake light signal when a threshold voltage indicative of the 15 brake light signal being turned ON is detected as being exceeded.

9. A brake ller according to claim 7 or 8, wherein the power tap circuit includes a tail light circuit having at least a tail light stor adapted to supply the power from the tail light signal when a threshold voltage indicative of the tail light signal being turned ON is detected as being exceeded. 20

10. A brake controller ing to claim 9, wherein the processor includes a control loop adapted to determine RMS current drawn from the tail light signal and the brake light signal, compare the RMS current with a RMS current limit, and limit the power supplied from the tail light signal and or the break light signal if the RMS current exceeds the RMS current limit. 25

11. A brake controller according to any one of claims 1 to 10, wherein the brake controller further es power electronics, in communication with the processor, adapted to generate and output the g control signal to control tion of the brakes of the towed vehicle braking system.

12. A brake controller ing to claim 11, wherein the brake light circuit has an isolation transistor adapted to be turned OFF when the braking l signal is outputted by the power electronics to prevent the towing vehicle from detecting that brake lights of the towed vehicle are turned ON. 5

13. A brake controller according to any one of claims 1 to 12, wherein the brake controller generates the braking control signal to the towed vehicle braking system when a threshold voltage tive of the brake light signal being turned ON is detected as being exceeded.

14. A brake controller according to claim 13, n the brake controller loads the 10 brake light signal with a test load greater than 0.1mA, and substantially disables the test load when voltage of the brake light signal is detected as falling below the threshold e, in order to prevent the towing vehicle from detecting connection of the towed vehicle.

15. A brake controller according to any one of claims 1 to 14, wherein the brake 15 controller further includes busbars disposed between the input connector and the output connector, and the processor and the inertial sensor are implemented in a module having a Printed Circuit Board (PCB), n connections from the rs terminate at the PCB.

16. A brake controller according to claim 15, n the module and the 20 connections from the bus-bar that terminate at the PCB are housed within the housing.

17. A brake controller according to claim 15 or 16, wherein the connections from the busbars are pins inserted into the busbars and the connections terminate at the PCB into holes in the PCB being sized to provide an interference fit with the 25 connections, thereby providing electrical connection and ical support to the

18. A brake controller according to any one of claims 1 to 17, wherein the brake controller is formed in a socket of the towing vehicle.

19. A brake controller according to any one of claims 1 to 17, n the brake controller is formed in a plug adapted to be received in a socket of the towing vehicle.

20. A brake controller according to any one of claims 1 to 17, wherein the input connector includes an input plug adapted to be ed in a socket of the towing 5 vehicle thereby ically and mechanically connecting the brake ller to the towing vehicle, and the output connector includes an output socket adapted to receive a plug connected to the towed vehicle.

21. A brake controller according to claim 20, wherein the input plug is a 12-pin plug, the socket of the towing e is a 12-pin socket, the output socket is a 12-pin 10 socket and the plug connected the towed vehicle is a 12-pin plug.

22. A brake controller for a towed vehicle braking system, said brake controller adapted to te a braking control signal to the towed vehicle braking system, the brake controller including: a module having an inertial sensor including plural sensor axes for generating 15 sensor data associated with each sensor axis and a processor for processing said sensor data to estimate a ration of the towing vehicle; and a loom including input connections for electrical connection to a towing vehicle and output connections for electrical connection to a towed vehicle, wherein the brake controller is electrically connected to the towing vehicle via 20 the input connections and to the towed vehicle via the output connections, wherein the brake controller including the inertial sensor and the processor receive power from the towing vehicle, and wherein the module is attached to the loom, and whereby the brake controller is adapted to generate and output the braking 25 control signal to l activation of brakes of the towed vehicle braking system based on the deceleration of the towing vehicle estimated by the processor and a brake light signal received by the processor from the towing vehicle via the input connections.

23. A brake controller according to claim 22, wherein the sor and the inertial 30 sensor are implemented on a Printed Circuit Board (PCB) of the module, and end wires of the loom are encapsulated separately to an enclosure containing the PCB.

24. A brake controller according to claim 22 or 23, wherein the module and at least part of the wires of the loom that terminate at the PCB are either sealed in an enclosure, over-moulded, or potted, thereby providing insulation and ical support to the module. 13 13 Towed Vehicle Braking System 5 1 Towed Vehicle Braking System 5 1 20 20 12 al Sensor 4 12 1 1 6