AU2015207894B2 - Vehicle test target for testing autonomous emergency braking systems - Google Patents

Abstract

The present disclosure relates to a vehicle test target for simulating an appearance of a vehicle during testing of collision prevention safety systems. A vehicle test target for simulating an appearance of a motor vehicle from at least one aspect includes an outer cover contoured to resemble at least a portion of an exterior of the motor vehicle. The outer cover includes at least part of an exterior bodywork of the motor vehicle and a frame to support the outer cover. 17/18 103 Measure RCS of a 101 motor vehicle 105 Measure RCS of a vehicle target simulating the motor vehicle Reconfigure radar reflectors 107 113 Compare RCS of motor vehicle with RCS of vehicle target 109 Deviation N between RCS N within acceptable bounds? Yes END 111 Fig. 17

Description

17/18

103 Measure RCS of a 101 motor vehicle

105 Measure RCS of a vehicle target simulating the motor vehicle

Reconfigure radar reflectors

107 113 Compare RCS of motor vehicle with RCS of vehicle target

109

Deviation N between RCS N within acceptable bounds?

Yes

END 111

Fig. 17

Technical Field

[1] The present disclosure relates to a vehicle test target for simulating an appearance of a vehicle during testing of collision prevention safety systems.

Background

[2] Vehicle collisions can cause damage to vehicles and property and more importantly injury and death. One form of vehicle to vehicle collision is known as a 'rear-end collision' where a vehicle collides with another vehicle in front of it. Such a collision may occur if the vehicle in front slows down or stops and the vehicle behind fails to adequately slow or stop to prevent a collision. The failure to slow down or stop may be caused by different factors, including inattention by the driver of the following vehicle, inadequate reaction time of the driver, or inadequate distance between the vehicles.

[3] To avoid or mitigate the risk of collisions, some vehicle manufacturers have incorporated safety technology that anticipates conditions that may lead to a collision. Such safety technology may provide warnings to the driver and/or actively intervene with the driving controls to avoid a collision or reduce the impact of a collision.

[4] Known safety technology include Autonomous Emergency Braking ('AEB') systems that apply braking independently of the driver. An AEB system may include one or a combination of sensors such as radar, lidar, and video (including '3D technology' such as stereo cameras and/or time-of-flight cameras). The AEB system anticipates potential collisions by sensing other vehicles (in particular vehicles ahead of the AEB equipped vehicle), and performing real-time calculations to determine possible future collision conditions based on one or more of the speed and acceleration (or deceleration) of both the AEB equipped vehicle and the vehicle in front, and the distance between the vehicles. If the driver of the AEB equipped vehicle does not apply the necessary driving controls to avoid the collision, the AEB system can apply braking to avoid or reduce the impact of the collision.

[5] It is known that motoring, insurance, standards, and regulatory bodies perform safety test on vehicles. This allows confirmation of manufacturer's claims to safety features as well as allowing comparison between different vehicles types. To test AEB systems, it is known to provide a vehicle target that includes an inflatable balloon structure to simulate the rear portion of a car. The inflatable balloon structure is provided so that if the AEB system of the vehicle being tested ('the test vehicle') fails to avoid a collision with the vehicle target, damage to the test vehicle and the vehicle target is minimised.

[6] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[7] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

Summary

[8] The present disclosure provides a vehicle test target for simulating an appearance of a motor vehicle from at least one aspect including: an outer cover contoured to resemble at least a portion of an exterior of the motor vehicle and wherein the outer cover includes an actual exterior bodywork of the motor vehicle from a rear end to at least a rear most axle; a frame to support the outer cover; and one or more radar reflectors to modify radar reflection characteristics of the vehicle test target to enhance resemblance to the motor vehicle.

[9] The inclusion of at least part of an exterior bodywork of the motor vehicle advantageously assists in providing an accurate appearance of the exterior portion of a real motor vehicle.

[10] In one form, the vehicle test target further includes a set of wheels supporting the frame. Following an impact from a test vehicle, the wheels aid movement of the vehicle test target away from the test vehicle. This promotes an elastic collision between the vehicle test target and the test vehicle, thereby reducing potential damage caused by the impact.

[11] In one form, the vehicle test target includes at least one brake associated with at least one of the wheels, wherein the brake is operative to stop movement of the vehicle test target. In a further form, the control of the brake is by remote control.

[12] In one form, the vehicle test target includes: a bumper located to receive impact from a test vehicle; and an energy absorbing means between the bumper and the frame, wherein at least some of the kinetic energy transferred from the impact of the test vehicle to the bumper is absorbed by the energy absorbing means. In a further form, the energy absorbing means includes at least one spring and at least one damper.

[13] In one form of the vehicle test target, the outer cover resembles the portion of the exterior of the motor vehicle from a rear end to at least a rear most axle.

[14] In one form, the vehicle test target further includes selectively operable lights to resemble brake lights of the motor vehicle.

[15] In one form, the vehicle test target further includes one or more radar reflectors located to modify radar reflection characteristics of the vehicle test target to enhance resemblance to the motor vehicle. A radar reflection characteristic may include, but is not limited to, the radar cross-section ('RCS') of the motor vehicle from a rear aspect.

[16] In one form, the vehicle test target further includes side mirrors extending from the frame to resemble side mirrors of the motor vehicle.

[17] In one form, the vehicle test target further includes one or more bluffs to resemble tyres associated with a rear most axle of the motor vehicle.

[18] In one form, the vehicle test target further includes a wheelie bar to inhibit the vehicle test target from flipping following an impact from a test vehicle.

[19] In one form, the frame comprises a space frame.

[20] The present disclosure also provides a vehicle target system for simulating an appearance of a motor vehicle from at least one aspect, the system allowing simulation of a desired model of motor vehicle selected from a plurality of models of motor vehicles, the system including: a plurality of outer covers for simulating the plurality of models of motor vehicles, each outer cover contoured to resemble at least a portion of an exterior of a respective model of motor vehicle, wherein the outer cover includes an actual exterior bodywork of the motor vehicle from a rear end to at least a rear most axle; a frame provided to support any one of the plurality of outer covers, wherein the outer cover is releasably attached to the frame; and one or more radar reflectors, wherein one or more radar reflectors are releasably attached to the frame to modify radar reflection characteristics of the vehicle test target to enhance resemblance to the motor vehicle, wherein the outer cover contoured to resemble the desired model of motor vehicle is attached to the frame to provide a vehicle test target simulating the appearance of the desired model of motor vehicle, and wherein a configuration of the one or more radar reflectors is attached to the frame to enhance resemblance to the desired model of motor vehicle.

[21] In one form of the vehicle target system, a set of wheels are releasably attached to the frame, wherein following an impact from a test vehicle the wheels aid movement of the vehicle test target away from the test vehicle, the system further including: a plurality of sets of wheels, wherein at least one set of wheels has a different overall diameter to at least another set of wheels; wherein a set of wheels is selected and attached to the frame to provide a height of the vehicle test target that resembles the desired model of motor vehicle.

[22] In one form of the vehicle target system, one or more radar reflectors are releasably attached to the frame to modify radar reflection characteristics of the vehicle test target, the system further including: a plurality of radar reflectors, wherein a configuration of the one or more radar reflectors is attached to the frame to enhance resemblance to the desired model of motor vehicle.

[23] The present disclosure also provides a frame assembly for supporting an outer cover contoured to resemble at least a portion of an exterior of a motor vehicle, the frame assembly and supported outer cover providing a vehicle test target for simulating an appearance of a motor vehicle from at least one aspect, the frame assembly including: a space frame for supporting the outer cover; and a set of wheels supporting the frame, wherein following an impact from a test vehicle, the wheels aid movement of the vehicle test target away from the test vehicle.

[24] In one form, the frame assembly further includes at least one brake associated with at least one of the wheels, wherein the brake is operative to stop movement of the vehicle test target.

[25] In one form, the frame assembly further includes: a bumper located to receive impact from a test vehicle; and an energy absorbing means between the bumper and the frame, wherein at least some of the kinetic energy transferred from the impact of the test vehicle to the bumper is absorbed by the energy absorbing means.

[26] In one form, the frame assembly further includes one or more radar reflectors located to modify radar reflection characteristics of the vehicle test target for enhancing resemblance to the motor vehicle.

Brief Description of Drawings

[27] Fig. 1 is a perspective view of a vehicle test target according to one embodiment with an outer cover separated from a frame;

[28] Fig. 2 is a front perspective view of the vehicle test target with the outer cover attached to, and supported by, the frame;

[29] Fig. 3 is a rear perspective view of the vehicle test target;

[30] Fig. 4 is a side view of the vehicle test target;

[31] Fig. 5 is a rear view of the vehicle test target;

[32] Fig. 6 is a front view of the vehicle test target;

[33] Fig. 7a is a front perspective view of a frame assembly for supporting the outer cover of the vehicle test target, the frame assembly including the frame and a set of wheels supporting the frame;

[34] Fig. 7b is a simplified front perspective view of the frame assembly of Fig. 7a;

[35] Fig. 8a is a rear perspective view of the frame assembly of Fig. 7a;

[36] Fig. 8b is a simplified rear perspective view of the frame assembly of Fig. 8a;

[37] Fig. 9a is a side view of the frame assembly of Fig. 7a;

[38] Fig. 9b is a simplified side view of the frame assembly of Fig. 9a;

[39] Fig. 10 is a rear view of the frame assembly of Fig. 7a;

[40] Fig. 11a is a front view of the frame assembly of Fig. 7a;

[41] Fig. 1lb is a simplified front view of the frame assembly of Fig. 11a;

[42] Fig. 12 is a simplified top view of the frame assembly of Fig. 7a;

[43] Fig. 13 is a top rear view of the frame assembly of Fig. 7a;

[44] Fig. 14 is a close up of a brake associated with one of the wheels of the frame assembly of Fig. 7a;

[45] Fig. 15 is a top side view of a bumper and energy absorbing means of the frame assembly of Fig. 7a;

[46] Fig. 16 is a rear perspective view of an embodiment of an outer cover for the vehicle test target;

[47] Fig. 17 is a flow diagram of a method of adjusting a radar reflection characteristic of a vehicle test target to match that of the motor vehicle that is being simulated; and

[48] Fig. 18 is a side view of a frame assembly according to one embodiment having an outer cover support subassembly separated from a lower frame subassembly.

Description of Embodiments

Overview

[49] An embodiment of a vehicle test target for simulating an appearance of a motor vehicle will now be briefly described with reference to Figs. 1 to 6. The vehicle test target 1 includes an outer cover 3 that is contoured to resemble a portion of an exterior the motor vehicle. The vehicle test target 1 further includes a frame 5 to support the outer cover 3. The appearance of the motor vehicle from an external aspect is provided by the contour of the outer cover 3. The outer cover 3 includes at least part 11, 13, 15 of an exterior bodywork of the motor vehicle.

[50] In the embodiment illustrated in Fig. 1, the vehicle test target 1 has two major assemblies. The first assembly includes the outer cover 3 that resembles an exterior of a model (or type) of motor vehicle. The second assembly is a frame assembly 7 formed by the frame 5 supported by a set of wheels 9 that assist movement of the vehicle test target 1. The outer cover 3 is releasably attached to the frame 5 of the frame assembly 7 to provide the vehicle test target 1. Different outer covers 3, corresponding to different models (or types) of motor vehicles, may be attached to the frame 5. To provide a vehicle test target 1 that simulates the appearance of the desired model of motor vehicle, the outer cover 3 corresponding to the desired model is attached to the frame 5.

[51] The use of the vehicle test target 1 will now be briefly described. The vehicle test target 1 is prepared by attaching an outer cover 3, resembling a desired model of motor vehicle, to the frame 5. A test vehicle (i.e. the AEB equipped vehicle being tested) is driven (remotely or by a person) towards the vehicle test target 1 in a direction such that, from the perspective of the test vehicle, the vehicle test target 1 has the appearance of a real motor vehicle. This allows testing of the AEB system by providing a simulated vehicle for the sensors of the AEB system to detect. In some embodiments of the test, the test vehicle is driven at speeds of between 5-30 km/h at a stationary vehicle test target 1.

[52] The AEB system of the test vehicle may operate to prevent a collision with the vehicle test target 1. However if the AEB systems fails to intervene, the test vehicle will collide with the vehicle test target 1. Following an impact from a test vehicle, the wheels 9 of the vehicle test target 1 allow the vehicle test target 1 to roll away from the test vehicle. This free movement of the vehicle test target 1, along with the light weight of the vehicle test target 1 compared to an actual motor vehicle, promotes an elastic collision. This reduces any damage to both the test vehicle and vehicle test target 1.

[53] The parts of the test vehicle 1 will now be described in further detail.

Outer cover

[54] Referring to Figs. I to 6, and 15, the outer cover 3 includes parts of an exterior bodywork of an actual motor vehicle to provide an accurate representation of the contours of the exterior portion of the motor vehicle. The outer cover 3 in one embodiment has parts of the rear bodywork of a motor vehicle including the rear trunk (boot) lid 11, rear quarter panels 13, and the rear bumper 15. This provides an accurate appearance of the motor vehicle from a rear aspect as best illustrated in Fig 5. In addition to simulating the appearance of the width and height of a motor vehicle, the vehicle test target 1 also simulates prominent features at the rear of the motor vehicle having depth (in the longitudinal axis), such as the bumper 15 and/or trunk that may stand proud from the remainder of the motor vehicle.

[55] Furthermore, use of the actual bodywork may better simulate not only the visual shape, but the material and radar signature of the motor vehicle. This may provide a more realistic target compared to known vehicle targets for testing AEB systems.

[56] The outer cover 3 is provided with an interface means for allowing releasable attachment to the frame 5. In one embodiment, the interface means includes a plurality of apertures (not shown) in the outer cover 3 for receiving corresponding fastening bolts (56) that are inserted through the apertures and secured into threaded sockets (27) of the frame 5. It is to be appreciated other interface means for releasably attaching the outer cover 3 may be used, such as latches, locks, sockets, and other fasteners.

[57] In some embodiments, the outer cover 3 may include substitute or modified parts from those corresponding parts on an actual (donor) motor vehicle. In one embodiment the rear windscreen is removed and replaced with an opaque fabric screen 17. The removal of the rear windscreen reduces the overall weight of the vehicle test target 1 which is advantageous in reducing damage to both the test vehicle and the vehicle test target 1 in the event of a collision. In addition to substitution of parts, it is to be appreciated other weight reduction measures can be made such as carving out parts of the bodywork that would not be visible from the perspective of the test vehicle. This allows reduction in weight whilst maintaining the contour of the exterior of the motor that is detected by sensors of the test vehicle.

[58] The rear bumper 15 is modified with a cut out 19, best illustrated in Fig. 16, to provide clearance for the installation of a bumper 21 (discussed in further detail below).

[59] The rear light cluster 21 of the outer cover 3 are modified to allow selective operation of one or more of the brake lights, tail lights, indicator lights, reverse lights, rear fog lamps, etc. The operation of these lights may be done remotely by an operator through a remote control. Alternatively, the operation of lights may be pre-programed and controlled by a controller on board the vehicle test target, such as a printed circuit board with microcontrollers. The selective operation of the lights allows tests that simulate real life scenarios where the lights of a vehicle would be used, such as when brakes are applied, hazard/indicator lights used, etc. Operation of these lights may be of particular benefit when testing test vehicles with AEB systems that can detect and recognise these lights, and/or are affected by operation of these lights.

[60] A pair of bluffs 22 are provided to resemble rear tyres of the motor vehicle as best illustrated in Figs. 2, 3, and 5. The bluffs 22 include a black surface visible when viewing the vehicle test target 1 from the rear to simulate black tyres of a motor vehicle. The bluffs may further include a metallic material (or other radar reflective material) to simulate the radar signature of metal wheels of a motor vehicle. The bluffs 22 are advantageous as the wheels 9 of the vehicle test target 1 are made of narrow lightweight wheels to reduce weight, and consequently the wheels 9 do not have the appearance of normal motor vehicle wheels.

[61] In the illustrated embodiment, only the rear part of the exterior of the bodywork from the rear end bumper to approximately the rear most axle is provided. For the motor vehicle type illustrated, this provides substantially all of the exterior surface of a motor vehicle that would appear to another vehicle travelling behind the motor vehicle. However, it is to be appreciated that for other vehicle types more, or less, of the exterior bodywork would be required to simulate the appearance of a motor vehicle. For example, a hatchback car, with a rear windscreen and roof terminating close to the very rear of the car may require less of the actual bodywork on the outer cover 3 to simulate the car. On the other hand, a utility vehicle (in particular 'utes' as referred to in Australia) with the cabin terminating well forward of the rear axle, may require more bodywork forward of the rear axle to simulate the utility vehicle. In another embodiment, other portions of the exterior bodywork of the vehicle may be used. For example, the front bumper, bonnet, front quarter panel and front windscreen may be used to simulate a frontal aspect of a motor vehicle. In other embodiments and applications, it may be desirable to include substantially all the exterior body work of a motor vehicle. For example, if the test requires simulation of from other or multiple aspects of a motor vehicle such as from the side, front, or at other angles.

The frame assembly

[62] As discussed in Fig. 1, the frame assembly 7 includes the frame 5 and wheels 9. The frame assembly 7 also includes, in brief, the following components. A brake 31 selectively operable on wheel 9 (as shown in Figs. 2 and 14) to stop movement of the vehicle test target 1. A bumper 21 operatively connected to energy absorbing means 27 that in turn are mounted to the frame 5. The bumper 21 provides an initial impact point with a test vehicle and the energy absorbing means 27 absorbs at least some of the kinetic energy transferred to the bumper 21 from the impact of the test vehicle. Radar reflectors 45 are located on the frame to modify radar reflection characteristics of the vehicle test target 1 to resemble the motor vehicle. Similarly, side mirrors 47 (as shown in Fig. 2) extend from the frame to provide resemblance of side mirrors that would be on a real motor vehicle. Finally, wheelie bars 51 inhibit the vehicle test target from flipping over following an impact from a test vehicle. The components of the frame assembly 7 will now be discussed in detail below.

Frame

[63] Referring to Figs. 7a to 12, the frame 5 provides a supporting structure for components of the vehicle test target 1. The frame 5 includes a space frame of connected members 23 to provide a lightweight and rigid support to the various components. The members 23 may be formed of tubular members 23 with a square hollow section, rectangular hollow section, circular hollow section, or other profiles. In one embodiment, the frame 5 is formed by welding together members 23 made of square hollow sections to ease fabrication and to reduce costs. Appropriate materials may include tubular aluminium, steel, or other metals.

[64] The frame 5 includes outer cover supports 25 that interfaces with and supports the outer cover 3. In one embodiment, the ends of the outer cover supports 25 contain threaded sockets 27 that receive bolts (not shown) inserted through the apertures of the outer cover 3 . To attach the outer cover 3 to the frame 5, the outer cover 3 is located so that the apertures of the outer cover 3 are aligned with the corresponding threaded sockets 27 of the outer cover supports 25. Bolts (not shown) are passed through the apertures of the outer cover 3 and fastened into the threaded sockets 27 to secure the outer cover 3 to the outer cover supports 25. To detach the outer cover 3 from the frame 5, the bolts are removed, and the outer cover 3 lifted away from the outer cover supports 25.

[65] It is appreciated other variations and alternatives for attaching the outer cover 3 to the frame 5 may be used. For example, in one embodiment, threaded rods are secured into threaded sockets 27 instead of bolts. The outer cover 3 is attached to the frame 5 by lowering the outer cover 3 onto the frame 5 so that the threaded rods are aligned with, and pass through, the apertures of the outer cover 3. In one embodiment, the outer cover 3 may be further secured by tightening a nut onto the threaded rod to prevent the threaded rod from sliding out of the apertures of the outer cover 3. In an alternative embodiment, the outer cover supports 25 include spigots and the outer cover 3 includes sockets for receiving corresponding spigots of the outer cover supports. The outer cover 3 is attached to the frame by lowering the outer cover 3 so that the sockets receive the spigots. In yet another alternative embodiment, the spigots are provided at the outer cover 3 and receiving sockets are provided at the outer cover supports 25. In further embodiments, the sockets and spigots may be provided with coaxially aligned lock apertures for receiving a lock pin to lock the outer cover 3 to the frame 5. In another alternative, the outer cover 3 and the frame 5 are fastened together by latches, or other suitable fasteners.

[66] In yet another embodiment, the outer cover supports 25 are adjustable in length to provide a suitable height to match the location of the apertures at the outer cover 3. This is advantageous where outer covers 3 of different types of motor vehicles, with significantly different contours (and consequently a different internal contours of the outer cover), are used for the same frame 3. The outer cover supports 25 may be formed of telescoping members to provide adjustment of length. Alternatively, extension pieces can be secured to the threaded sockets 27 at the ends of outer cover supports 25 to provide additional length of the outer cover support as required.

[67] In yet another embodiment, the frame includes additional sub-assemblies as illustrated in Fig. 18. The frame 205 includes an outer cover support subassembly 204 and a lower frame subassembly 206. The outer cover support subassembly 204 includes outer cover supports 25 to support an outer cover 3. The lower frame subassembly 206 includes support members 23 for supporting various other components of the vehicle target as described above. In this embodiment, the outer cover support subassembly 204 is releasably attached to the lower frame subassembly 206 with releasable fastening means 224, such as a clevis joint and pin. This arrangement allows selective attachment of different outer cover support subassemblies 204 to the lower frame subassembly 206. This may be advantageous as the outer cover support subassembly 204 can be customised with specific outer cover supports 25 to fit with a particular outer cover 3. This may provide additional flexibility in adapting the frame 205 with outer covers 3 of various different models and types of motor vehicles. It may also assist in faster set up of the vehicle test target 1 by reducing, or eliminating, the need to adjust the length of the outer cover supports 25 to match the internal contour of a particular outer cover 3. In yet another embodiment, the outer cover support subassembly 204 may be fixed, permanently or temporarily, to a respective outer cover 3. Changing an outer cover 3 to provide a particular vehicle test target 1 in this embodiment may include firstly releasing the fastening means 224 and separating the outer cover support subassembly 204, fixed to an outer cover 3, from the lower frame subassembly 206. Subsequently, another outer cover support subassembly 204, fixed to another outer cover 3, is fastened to the lower frame subassembly 206.

Wheels

[68] The set of wheels 9 are attached to the frame 5 and allow the vehicle test target 1 to freely roll. This is advantageous to allow the vehicle test target 1 to roll away from the test vehicle after a collision to reduce potential damage to both the vehicle test target 1 and the test vehicle. To enhance free rolling of the vehicle test target 1 after impact, it is desirable to minimise the moment of inertia of the wheels 9. Therefore in one embodiment, spoke wheels such as those from bicycles are used. Use of bicycle wheels are also advantageous as they are commonly available parts and are generally cheaper that actual wheels of cars. Wheel covers 29 are provided on the outwardly facing sides of the wheels 9 to resemble the outward facing surface of real wheels of a motor vehicle.

[69] The set of wheels 9 in the illustrated embodiment is in a tricycle arrangement. This provides the minimum number of wheels 9 whilst providing a stable support for the vehicle test target. However, it is to be appreciated other configurations may be used, including four or more wheels.

[70] The size of the wheels 9 can be changed to vary the height of the vehicle test target 1. For example, a relatively smaller diameter wheel 9 will lower the outer cover 3 relative to the ground. Conversely, a relatively larger diameter wheel 9 will raise the outer cover 3 relative to the ground.

Brake

[71] Referring to Fig. 14 a brake 31 is provided on one of the wheels 9 to operatively slow and stop movement of the vehicle test target 1. In the illustrated embodiment, the brake 31 is based on a cantilever brake of a bicycle that operatively applies friction to the rim of the wheel 9. In one embodiment operation of the brake 31 is by remote control. A remote switch (not shown) is wired to allow selective operation of a solenoid actuator 33 which in turn operates the brake 31. In one form, the remote switch provides an electrical signal to operate one or more relay switches (not shown). The relay switch in turn completes an electrical circuit from battery 35 to the solenoid actuator 33.

[72] It is to be appreciated that in other embodiments, other alternatives and variations of the brake 31 may be used. In one form, the brake is in the form of a linear-pull brake. In a further form, the brake is a disc brake. In a further form, the brake is a hydraulically operated brake. In another form a brake is provide on more than one, or all of the wheels 9. In another variation, the remote control is a wireless system whereby a remote control transmitter provides control signals to a wireless receiver mounted on the vehicle test target 1, and the wireless receiver in turn provides the electrical signals that allow selective operation of the brakes.

[73] In yet another embodiment, the brake may be applied autonomously by the vehicle test target. For example, operation of the brake is pre-programed and controlled by an controller in the vehicle test target 1, such as a printed circuit board with microcontrollers, in conjunction with information from sensors such as accelerometers or rotary encoders coupled to the wheels. In one embodiment, the microcontrollers may be programmed to selectively operate the brakes after detection of a collision. To allow the vehicle test target 1 to roll away from the test vehicle, the microcontrollers may be programed to operate the brake after a delay from the initial acceleration caused by a collision by a test vehicle. Alternatively, the brakes may be programed to operate after determination that the collision has concluded. Such determination may be derived for example, if sensors in the vehicle test target do not detect further acceleration, or if the sensors detect deceleration. Alternatively proximity sensors, such as ultrasonic sensors, may be placed to detect the proximity of the test vehicle and the proximity information used to derive whether the collision has concluded. It is to be appreciated other sensors and methods may be used to determine conclusion of the collision.

Bumper and energy absorbing means

[74] Referring to Fig. 15, a bumper 21 is located to receive impact from a test vehicle. An energy absorbing means 37 is mounted between the bumper 21 and the frame 5, so that at least some of the kinetic energy transferred from the impact of the test vehicle to the bumper 21 is absorbed by the energy absorbing means 37. In the illustrated embodiment, the bumper 21 is mounted directly to a pair of energy absorbing means 37. The energy absorbing means 37 in turn are mounted to members 23 of the frame 5 as shown in Fig. 12.

[75] The bumper 21 includes a foam strip 39 that provides a contact surface to an impacting test vehicle. The foam strip 39 also absorbs some of the kinetic energy from the impact of the test vehicle. In one embodiment the foam strip is made of expanded polypropylene (EPP). The bumper 21 also includes support strip 41 that is relatively more rigid than the foam strip 39 to support the foam strip 39. In one embodiment the support strip 41 is made of aluminium. The support strip 41 is attached to mounts 43 that connect with the energy absorbing means 37.

[76] The energy absorbing means 27 include telescoping tubes 43, which contain a damper (not shown) and a coil spring (not shown). The energy absorbing means absorbs some of the energy to reduce damage to the vehicle test target and the test vehicle. The damper may include, but not limited to a hydraulic damper or a pneumatic damper. In one embodiment, the energy absorbing means are derived from 'shock absorbers' that are commonly used in suspension forks of mountain bikes. Advantageously, shock absorbers are resilient and will return the bumper 21 back to the pre-collision location. The use of commercially available shock absorbers also reduces fabrication costs of the vehicle test target 1. It is to be appreciated that other energy absorbing means 27 may be used, for example, a leaf spring, a gas filled balloon, a further foam element, etc.

Reflectors

[77] Reflectors 45 are located to modify radar reflection characteristics of the vehicle test target 1 to enhance the resemblance to the motor vehicle that the vehicle test target 1 is simulating. For the illustrated embodiment, one important radar reflection characteristic includes the RCS from a rear aspect. The reflectors 45 may include commonly used marine reflectors that are designed to reflect radar waves back towards the radar source. In the one embodiment the reflectors 45 are trihedral comer reflectors.

[78] Referring to the illustrated embodiment, three reflectors 45 are arranged and mounted to the frame 5 to provide enhanced radar reflection. This may be advantageous as the outer cover 3 may not provide all the radar reflection characteristics of a real motor vehicle it is trying to simulate. For example, the bumper 15 may be made of a relatively radar-transparent material. Accordingly in a real motor vehicle, radar waves may travel through the bumper 15 but reflect off the internal metal chassis and back through the bumper 15 toward the radar source. Therefore to simulate the reflection from the internal chassis, one or more reflectors 45 may need to be attached to the frame 5. Similarly, an additional reflector 45 may need to be located behind the fabric screen 17 to provide additional radar reflection to simulate the radar reflection of the area around the rear windshield.

[79] The radar reflection of a motor vehicle will vary depending on the type and model of vehicle. Therefore the location of reflectors 45 mounted on the frame to simulate one model (and corresponding outer cover 3) of motor vehicle may not be appropriate for another model of motor vehicle. Therefore the reflectors 45 are removably attached to the frame 5 so that they can be relocated to other parts of the frame to adjust the radar reflection characteristics. Adjustment of the radar reflection characteristics may also include using more, or less, radar reflectors 45, as well as using different sizes and types of radar reflectors.

[80] The adjustment and location of the reflectors 45 may be based on measurement and comparison of radar reflection characteristics (such as the RCS from a rear aspect) of the vehicle test target with that of a real motor vehicle. Where there are deviations in the radar reflection characteristics of the vehicle test target from that of a real motor vehicle, one or more reflectors 45 may be positioned to enhance radar reflection to match that of the real motor vehicle.

[81] An example of a method 101 of adjusting the radar reflection characteristic, in particular the RCS from a rear aspect, will now be described with reference to Fig. 17. The method 101 includes a first step 103 of measuring the RCS of a real motor vehicle with a RCS measurement device. After the RCS data of the real motor vehicle is obtained at step 103, a subsequent step 105 of measuring the RCS of a vehicle test target simulating the real motor vehicle is performed. After the RCS data of both the real motor vehicle and the vehicle test target 1 is obtained, the RCS data is compared at step 107. If it is determined at the following step 109 that the deviation between the RCS of the real motor vehicle and the vehicle test target 1 is within acceptable bounds, then the radar reflection characteristic of the vehicle test target 1 is correct and no adjustment is required and the method 101 ends at step 111. However, if it is determined at step 109 that the deviation between the RCS of the real motor vehicle and the vehicle test target 1 is not within acceptable bounds, then the method proceeds to step 113. At step 113, the radar reflectors 45 are reconfigured. This step 113 may include providing further reflectors 45, removing reflectors 45, adjusting the location of the reflectors, adjusting the orientation of the reflectors 45, or changing the type and size of reflectors 45. The amount and type of reconfiguration at step 113 may depend on how much deviation of the RCS determined during the comparison step 107. After the step 113 of reconfiguration of the reflectors 45, the method 101 goes back to the step 105 of measuring the RCS of the vehicle test target. The comparison step 107 and determination step 109 described above is then repeated.

[82] In a further embodiment, radar-absorbing material may be located on the frame 5 in cases where there is more radar reflection at particular areas of the vehicle test target 1 when compared to corresponding areas of a real motor vehicle. This may be caused by specific parts of the vehicle test target 1 that are not present in a real vehicle. Radar-absorbing materials may attenuate radar waves coming from the radar source. Alternatively, structures with surfaces designed to disperse radar waves in directions away from the radar source may be used to reduce radar reflection to the test vehicle.

Mirrors

[83] A pair of mirrors 47 is mounted on mirror support members 49 of the frame 5 (as shown, for example, in Fig. 11a). The pair of mirrors 47 may include real mirrors from the motor vehicle being simulated. The mirrors 47 simulate the side mirrors that may be detectable by sensors in an AEB equipped test vehicle.

Wheelie bars

[84] A pair of wheelie bars 51 extends downward and rearward away from the frame 5. At the distal end of the wheelie bars 51 are caster wheels 53 directed towards the ground. The wheelie bars 51 inhibit the vehicle test target 1 from flipping following an impact from a test vehicle. The caster wheels 53 assist in reducing friction of the wheelie bars 51 on the ground should the wheelie bars 51 contact the ground following an impact, thus allowing the vehicle test target 1 to freely roll away from the test vehicle.

[85] Although the illustrated embodiment includes a pair of wheelie bars 51 extending downward and rearward, it is to be appreciated other wheelie bars may be included to stabilise and to prevent flipping of the vehicle test target. For example, wheelie bars may extend downward and forward of the frame 5 to prevent flipping in the opposite direction. In another embodiment bars may extend sideways, similar to outriggers, to prevent sideways tipping of the vehicle test target.

Vehicle target system

[86] A vehicle target system for simulating the appearance of a variety of different models (or types) of motor vehicles is also disclosed. This system includes a plurality of outer covers 3, with each outer cover 3 resembling an exterior portion of a model (or type) of motor vehicle. A frame 5 of a frame assembly 7 is provided to support one or more of the plurality of outer covers 3. The outer covers 3 are releasably attached to the frame 3, so that operators can simulate a desired model of motor vehicle by attaching the outer frame 3, corresponding to the desired model, to the frame 5. If the operator wishes to simulate a different model of motor vehicle, the outer cover 3 of that different model is attached to the frame 5. This system advantageously allows a range of different types of vehicle test targets, so that test vehicles can be exposed to different types of simulated vehicles. This is important to confirm the reliability of AEB systems since in real world conditions, the AEB system will need to detect a wide range of different types, models, colours, and other variations of cars. In addition, this system may allow rapid change of outer covers 3 that may be damaged during a test.

[87] The system also includes sets of wheels 9 with different sizes. This allows the user to adjust the height of the vehicle test target 1 as desired. This adjustment allows simulation of different model of cars that have different heights. In addition, this allows simulation of the same model of cars at different heights to replicate varying wheel and suspension setups.

[88] The system also includes a number of reflectors 45, as well as reflectors having different characteristics. The system allows the user to locate one or more reflectors 45 (including ones with different reflection characteristics) to adjust the radar reflection characteristics of the vehicle test target 1. This may be done with reference to comparison radar characteristics of a real motor vehicle as discussed above. Alternatively, the radar reflectors 45 may be chosen to simulate changed radar reflection characteristics of the vehicle test target 1. For example, from modifications to the motor vehicle or changes in radar reflection due to the contents (such as cargo or luggage) of the motor vehicle.

Other advantages

[89] Known inflatable balloon structures of vehicle targets include a generally prism-like overall structure. Such a structure may not closely represent an actual vehicle and in attempts to better imitate the shape of an actual car for the sensors of an AEB system, it is known to provide the inflatable balloon structure with an outer cover having a two dimensional printed image of a vehicle. However this form of vehicle target may not provide sufficient imitation of the rear of a real vehicle for some sensors of an AEB equipped vehicle. For example, the prism-like structure of the balloon may not provide the necessary imitation of depth (along the longitudinal axis) of structural features of a real vehicle. Furthermore, many vehicles do not have a simple prism-like structure but instead comprise of curves, extensions, recesses and other structural features.

[90] In contrast, embodiments of vehicle test target of the present disclosure include at least part of an exterior bodywork of a motor vehicle. This advantageously assists in providing an accurate appearance of the exterior portion of a real motor vehicle for sensors of an AEB equipped vehicle. In particular, this provides features of depth that would not appear on a two dimensional printed image on the back of a known vehicle target.

[91] In addition to the advantages discussed above, embodiments of the vehicle test target 1 and vehicle target system also include the following advantages. The vehicle test target 1 may be lightweight, and in some embodiments in the order of approximately 80kgs. The vehicle test target 1 may also be easily disassembled into components that can fit in a single truck or utility vehicle (such as a ute). Another advantage of embodiments of the vehicle test target 1 is that the components are readily available off-the-shelf or are easily modified off-the-shelf components. This reduces cost and eases fabrication.

[92] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (14)

CLAIMS:

1. A vehicle test target for simulating an appearance of a motor vehicle from at least one aspect comprising:

- an outer cover contoured to resemble at least a portion of an exterior of the motor vehicle and wherein the outer cover includes an actual exterior bodywork of the motor vehicle from a rear end to at least a rear most axle;

- a frame to support the outer cover; and

- one or more radar reflectors to modify radar reflection characteristics of the vehicle test target to enhance resemblance to the motor vehicle.

2. A vehicle test target according to any one of the preceding claims further comprising a set of wheels supporting the frame,

wherein following an impact from a test vehicle, the wheels aid movement of the vehicle test target away from the test vehicle.

3. A vehicle test target according to claim 2 further comprising at least one brake associated with at least one of the wheels, wherein the brake is operative to stop movement of the vehicle test target.

4. A vehicle test target according to claim 3 wherein the control of the brake is by remote control.

5. A vehicle test target according to any one of the preceding claims further comprising:

- a bumper located to receive impact from a test vehicle; and

- an energy absorbing means between the bumper and the frame, wherein at least some of the kinetic energy transferred from impact of the test vehicle to the bumper is absorbed by the energy absorbing means.

6. A vehicle test target according to claim 5 wherein the energy absorbing means includes at least one spring and at least one damper.

7. A vehicle test target according to any one of the preceding claims further comprising selectively operable lights to resemble brake lights of the motor vehicle.

8. A vehicle test target according to any one of the preceding claims further comprising side mirrors extending from the frame to resemble side mirrors of the motor vehicle.

9. A vehicle test target according to any one of the preceding claims further comprising one or more bluffs to resemble tyres associated with a rear most axle of the motor vehicle.

10. A vehicle test target according to any one of the preceding claims further comprising a wheelie bar to inhibit the vehicle test target from flipping following an impact from a test vehicle.

11. A vehicle test target according to any one of the preceding claims wherein the frame comprises a space frame.

12. A vehicle target system for simulating an appearance of a motor vehicle from at least one aspect, the system allowing simulation of a desired model of motor vehicle selected from a plurality of models of motor vehicles, the system comprising:

- a plurality of outer covers for simulating the plurality of models of motor vehicles, each outer cover contoured to resemble at least a portion of an exterior of a respective model of motor vehicle, wherein the outer cover includes an actual exterior bodywork of the motor vehicle from a rear end to at least a rear most axle;

- a frame provided to support any one of the plurality of outer covers, wherein the outer cover is releasably attached to the frame; and

- one or more radar reflectors, wherein one or more radar reflectors are releasably attached to the frame to modify radar reflection characteristics of the vehicle test target to enhance resemblance to the motor vehicle,

wherein the outer cover contoured to resemble the desired model of motor vehicle is attached to the frame to provide a vehicle test target simulating the appearance of the desired model of motor vehicle, and

wherein a configuration of the one or more radar reflectors is attached to the frame to enhance resemblance to the desired model of motor vehicle.

13. A vehicle target system according to claim 12 wherein a set of wheels are releasably attached to the frame, wherein following an impact from a test vehicle the wheels aid movement of the vehicle test target away from the test vehicle, the system further comprising:

- a plurality of sets of wheels, wherein at least one set of wheels has a different overall diameter to at least another set of wheels;

wherein a set of wheels is selected and attached to the frame to provide a height of the vehicle test target that resembles the desired model of motor vehicle.

14. A vehicle target system according to any one of claims 12 to 13 comprising a vehicle test target according to any one of claims 1 to 11.