GB2349469A

GB2349469A - An ultrasonic ranging sensor mounted in a fixed orientation in a housing

Info

Publication number: GB2349469A
Application number: GB0010379A
Authority: GB
Inventors: Heong Jong
Original assignee: MOTOSONICS Ltd; Sung Bo Ind Co Ltd
Current assignee: MOTOSONICS Ltd; Sung Bo Ind Co Ltd
Priority date: 1999-04-30
Filing date: 2000-05-02
Publication date: 2000-11-01
Anticipated expiration: 2020-05-02
Also published as: GB0010379D0; GB9910130D0; GB2349469B

Abstract

An ultrasonic sensor apparatus is provided, for mounting in the bumper of a vehicle to indicate proximity to obstacles. The apparatus comprises a housing 10 designed to be fitted in a vehicle bumper, within which is held a sensor module 24 surrounded by a rubber potting compound 18. The sensor module 24 is held at a predetermined angle by a combination of the potting compound 18 and an angled pedestal 26. Manufacture of sensor apparatus with different angles of sensor module 24 is easily achieved with standardised components by replacing the angled pedestal 26 with a pedestal of a different angle during manufacture.

Description

SENSOR APPARATUS The present invention relates to a sensor apparatus suitable for mounting on a motor vehicle, in order to determine the distance between the vehicle and an object.

The invention may also be used to produce an audible or visible warning to alert the user of the vehicle's proximity to an object.

Systems for indicating the presence of an obstruction behind a reversing vehicle to the vehicle driver are well known. Such systems typically rely on mounting one or more distance sensors at the rear of the vehicle. The sensors may be ultrasonic or electromagnetic, or may use some other sensing method.

It is common for such sensors to be mounted on the vehicle bumper or fender, as this is typically at a suitable height for detection of the majority of likely obstacles. Further, bumpers of vehicles without preinstalled sensors may often be readily modified to enable retrofitting of a sensor to the bumper.

In order for such systems to function properly, the sensors must be aligned at a predetermined orientation.

As the configuration of bumpers varies from vehicle model to vehicle model, this necessitates the production of a range of sensors, the orientation of which may be suitable for only one specific model of vehicle. This also applies if the sensor is to be mounted elsewhere than on the bumper.

Systems are under development which are relatively insensitive to the orientation of the sensor, but such systems require more complex signal processing or more sensitive electronic components in order to compensate for their tolerance to misalignment. Such systems are therefore likely to be relatively expensive and less robust than conventional sensors.

It is among the objects of embodiments of the present invention to obviate or alleviate these and other disadvantages of conventional vehicle sensors.

According to one aspect of the present invention, there is provided a sensor apparatus comprising a housing and a sensor module, the sensor module being potted within the housing to maintain the sensor module in a predetermined fixed orientation with respect to the housing.

This apparatus has the advantage that the potting may be used to provide a sensor apparatus with a sensor module in any desired fixed orientation relative to the housing both rapidly and inexpensively. Further, the housing may be standardised in order to enable rapid and simple retrofitting of the apparatus to a vehicle bumper, and also minimise production costs, while still enabling the orientation of the sensor to be optimized for each particular model of vehicle.

Preferably, the sensor module is potted within the housing by means of a settable rubber compound. This provides strength to the apparatus while the resilience of the rubber compound will protect the sensor module components in the event of knocks and the like.

Alternative potting compounds may of course be utilized, for example, epoxy resin, or plastics materials.

Preferably, the apparatus further comprises a pedestal for location between the sensor module and a mounting face of the housing and on which the sensor module may be positioned prior to setting of the potting compound. Most preferably, a surface of the pedestal is angled relative to the mounting face such that the sensor module itself is also angled. Thus, the angle at which the sensor module is fixed may be easily varied by selecting alternative pedestals.

According to a preferred aspect of the present invention, there is provided a sensor apparatus comprising a housing and a sensor module, the sensor module being retained in the housing in a predetermined fixed orientation with respect to the housing by means of an orientation member.

Preferably the orientation member is in the form of a sleeve surrounding the sensor module. However, alternative orientation members may be used, for example, a number of fingers of varying lengths in contact with the sensor module, or a base member in contact with the lower portion of the sensor module.

Preferably the orientation member is formed from a rubber compound, to provide resilience. Alternative materials may be used, for example, epoxy resins or plastics materials. Preferably also the orientation member is moulded, most preferably injection moulded. A number of different configurations of orientation member may be made available, in order to retain the sensor module at different orientations relative to the housing. This provides a simple and inexpensive means of mass-producing sensor apparatus in a range of preferred orientations.

Preferably, the sensor module is an ultrasonic sensor, and in particular a module which transmits and then analyses a reflected signal.

Preferably, the housing is adapted to be retrofitted into a vehicle rear bumper. Preferably, the housing is generally cylindrical, and thus may be located in a drilled hole. Alternatively, the sensor housing may be fitted in the bodywork of a vehicle if the rear bumper is considered unsuitable; or the housing may be mounted on a bracket to be mounted on the vehicle.

Preferably, the sensor module is retained at an angle to a front face of the housing. Most preferably, the angle is between 5 and 15 .

Preferably, the sensor apparatus further comprises a control unit and display unit. Most preferably, control and display functions are combined in a single unit.

Preferably also, the control/display unit is located remotely from the sensor module. Most preferably, the control/display unit is located in the cabin of a vehicle.

Preferably, the apparatus generates one or both of an audible warning and a visual warning which varies according to the distance of the sensor module from an object.

According to a further aspect of the present invention there is provided a method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: providing a housing; locating an orientation member within the housing; and locating a sensor module within the housing, such that the orientation member retains the sensor module within the housing in a fixed predetermined orientation relative thereto.

The sensor module may be located relative to the orientation member prior to locating the member in the housing.

According to another aspect of the present invention there is provided a method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: providing a housing; locating a sensor module at least partially within the housing in a predetermined position relative thereto; providing a settable material between the sensor module and the housing; and allowing the settable material to set to fix the position of the sensor module relative to the housing.

According to a further aspect of the present invention there is provided a method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: locating an angled pedestal in a housing; locating a sensor module on the angled pedestal; and potting the sensor module in a rubber potting compound.

These and other aspects of the present invention will now be described by way of example only and with reference to the accompanying figures, in which : Figure 1 shows a plan view of a sensor apparatus in accordance with an embodiment of the present invention; Figure 2 shows a side view of the sensor apparatus of Figure 1; Figure 3 shows a front view of the housing of an embodiment of the present invention; Figure 4 shows a sectional side view on line A-A of Figure 3; Figure 5 shows a schematic diagram of the location of the sensor apparatus of Figure 1 in a vehicle; and Figure 6 shows an example of the apparatus of Figure 5 in use.

Referring first of all to Figures 1 and 2, these show plan and side views of the housing 10 of a sensor apparatus 11 according to an embodiment of the present invention, the housing 10 containing an ultrasonic sensor module 24 (Figures 3 and 4), as will be described. The housing 10 is generally cylindrical and includes a lip 12, and two diametrically opposed spring fingers 13, each defining a series of ramped teeth 14, which serve to aid retention of the housing 10 in a vehicle bumper; if a hole of slightly large diameter than the housing 10 is drilled in the bumper, the housing 10 may be located in the hole with the rear face of the lip 12 engaging the bumper outer surface and the teeth 14 engaging the wall of the hole or the bumper inner surface. Extending from the rear of the housing 10 is a cable 16, which links the sensor module 24 to other parts of the system, including a control and display unit 54 (Figure 5) for location in a vehicle cab.

Figure 3, a front view of the apparatus of Figure 2, shows additionally a region of rubber sleeve 18 surrounding the sensor module 24, with a window 22 of the sensor module 24 being located clear of the sleeve 18.

Further details of the device may be seen in Figure 4, a longitudinal cross-section of the apparatus taken on line A-A of Figure 3. It will be observed that the sensor module 24 is located within a chamber 25 defined by the housing side wall 27 and an end wall 29 of an electrical component housing 31. The chamber 25 is substantially filled by the sleeve 18.

The sensor module 24 is mounted on a circular pedestal 26 with a module support surface 28 oriented at an angle A (in this example 10 ) to the pedestal surface 33 in contact with the wall 29. Accordingly, the module 24 lies at angle A to the front surface of the housing 10, and at corresponding angle B to the longitudinal axis of the housing 10, this orientation being maintained by the sleeve 18. In an alternative embodiment of the invention, pedestal 26 may be omitted from the apparatus, with sensor module 24 being retained in the correct orientation by the sleeve 18 alone. In a further alternative embodiment, the sleeve 18 may be replaced by a potting compound which, once set, will retain the module 24 in the orientation determined by the pedestal 26. As noted above, the rear of the housing 10 contains a component housing 31 occupied by signal transmission and receiving components 30,32 connected to the sensor module 24, and to the cable 16.

Turning now to Figure 5, this shows an articulated truck 40 fitted with sensor apparatus 11 according to the present invention. Two sensor units 11 are mounted on the rear of the truck 40, spaced at least one metre apart. A cable 16 leads from each unit 11 to a respective connector 44, and then to a Y-junction 46 which connects to a power supply connection 48. Power for the units 11 is obtained via a power line 49 from the vehicle reversing light 52.

The output from the units 11 is carried to the display/control unit 54, mounted in the cab 56 of the truck 40, by a main cable 50.

In use, engaging reverse gear supplies power to the reversing light 52, and thus also to sensor units 11, so ensuring that the units 11 are active on reversing. The display/control unit 54 may also send and receive signals along control cables 50 and 16 to the sensor units 11, in order to adjust operating parameters of the units.

An example of the operation of the apparatus is illustrated in Figure 6.

When the apparatus is activated, it can detect obstacles at least up to 300cm to the rear of the vehicle.

At distances of 300-200cm from the truck, the control/display unit 54 emits a series of pulses of low frequency sound, and may have a visual warning as well, such as coloured lights (typically a green light). From 200-lOOcm distances, the frequency of the sound produced gradually rises as does the frequency of pulses, and the displayed light may change to amber, and from 100-60cm from the obstacle a very high frequency sound is produced, and the unit 54 displays a red light.

Once the truck reaches 60cm from the obstacle, the apparatus produces a high frequency continuous sound, indicating that the driver should stop the vehicle.

The control/display unit 54 may be used to activate or deactivate the sensor units 11 or to disable either or both of the visual and aural distance indicators.

In the above example, the sensor module 24 is located an angle of 10 to the horizontal (assuming the face of the truck bumper is vertical). However, for other applications it may be preferred that the sensor module 24 is mounted at a different angle relative to the housing 10. To achieve this, an alternative pedestal 26 is provided, with an appropriately angled surface 28; the sensor module 24 will assume the desired orientation, which will be fixed by an appropriate sleeve 18 being fitted around the module 24. Alternatively, it is merely necessary to provide an alternative sleeve 18 formed such as to hold the module 24 in a different orientation. In another embodiment, an alternative pedestal 26 may be used in conjunction with a potting compound; the orientation of the sensor module 24 will be fixed once the potting compound has been injected into the chamber 25 and has solidified.

Also, the provision of a single control and display unit 54 facilitates fitting of the apparatus.

It will be clear that the foregoing is for illustrative purposes only, and that various modifications and improvements may be made to the apparatus and method described herein without departing from the scope of the invention.

Claims

CLAIMS 1. A sensor apparatus comprising a housing and a sensor module, the sensor module being potted within the housing to maintain the sensor module in a predetermined fixed orientation with respect to the housing.
2. The sensor apparatus of claim 1 wherein the sensor module is potted within the housing by means of a settable rubber compound.
3. The apparatus of claim 1 or claim 2 comprising a pedestal for location between the sensor module and a mounting face of the housing and on which the sensor module may be positioned prior to setting of the potting compound.
4. The apparatus of claim 3 wherein a surface of the pedestal is angled relative to the mounting face such that the sensor module itself is also angled.
5. A sensor apparatus comprising a housing and a sensor module, the sensor module being retained in the housing in a predetermined fixed orientation with respect to the housing by means of an orientation member.
6. The apparatus of claim 5 wherein the orientation member is in the form of a sleeve surrounding the sensor module.
7. The apparatus of claim 5 wherein the orientation member comprises a number of fingers of varying lengths in contact with the sensor module.
8. The apparatus of claim 5 wherein the orientation member comprises a base member in contact with the lower portion of the sensor module.
9. The apparatus of claims 5 to 8 wherein the orientation member is formed from a resilient rubber compound.
10. The apparatus of claims 5 to 9 wherein the orientation member is moulded.
11. The apparatus of claim 10 wherein the orientation member is injection moulded.
12. The apparatus of claims 5 to 11 wherein the sensor module is an ultrasonic sensor.
13. The apparatus of claim 12 wherein the sensor module transmits and then analyses a reflected signal.
14. The apparatus of claims 5 to 13 wherein the housing is adapted to be retrofitted into a vehicle rear bumper.
15. The apparatus of claims 5 to 14 wherein the housing is generally cylindrical.
16. The apparatus of claims 5 to 15 wherein the sensor module is retained at an angle to a front face of the housing.
17. The apparatus of claim 16 wherein the angle is between 5 and 15 .
18. The apparatus of claims 5 to 17, further comprising a control unit and display unit.
19. The apparatus of claim 18 wherein control and display functions are combined in a single unit.
20. The apparatus of claim 18 or 19 wherein the control and display units are located remotely from the sensor module.
21. The apparatus of claim 20 wherein the control and display units are located in the cabin of a vehicle.
22. The apparatus of claims 5 to 21 wherein the apparatus, in use, generates one or both of an audible warning and a visual warning which varies according to the distance of the sensor module from an object.
23. A method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: providing a housing; locating an orientation member within the housing; and locating a sensor module within the housing, such that the orientation member retains the sensor module within the housing in a fixed predetermined orientation relative thereto.
24. The method of claim 23 comprising the further step of locating the sensor module relative to the orientation member prior to locating the member in the housing.
25. A method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: providing a housing ; locating a sensor module at least partially within the housing in predetermined position relative thereto; providing a settable material between the sensor module and the housing; and allowing the settable material to set to fix the position of the sensor module relative to the housing.
26. A method of manufacturing a sensor apparatus for vehicles and the like, the method comprising the steps of: locating an angled pedestal in a housing; locating a sensor module on the angled pedestal; and potting the sensor module in a rubber potting compound.