IMPACT TUBE FOR PEDESTRIAN PROTECTION SENSOR FOR A MOTOR VEHICLE

Abstract

Detection and injury mitigation system for a vehicle (10) to identify an object in an impact event, characterized in that the system comprises: an impact sensor (20) comprising a first and a second tube (66, 68), wherein at least one section of each of the tubes (66, 68) has a common axis; a first pressure sensor (30) to which the first pipe (66) is attached; a second pressure sensor (32) to which the second tube (68) is attached; and a housing (23) in which the sensors are located.

Description

TECHNICAL AREA

[0001] The disclosed inventive concept relates generally to pedestrian protection sensors for motor vehicles. More specifically, the disclosed inventive concept relates to a pedestrian protection sensor for a vehicle with an impact tube attached to a sensor unit. GENERAL STATE OF THE ART

[0002] Pedestrian-vehicle collisions are regrettable but known occurrences, as are collisions between vehicles and non-pedestrian objects. Vehicle-object collision mitigation systems are known that can identify the location and size of an object with which the vehicle has collided. If such systems are related to the front of the vehicle, the width and location of the impacting object help the vehicle's collision mitigation system determine which, if any, active restraint devices should be deployed. Such systems can cause the vehicle to react differently depending on whether the impacting object is a pedestrian or a non-pedestrian object.

[0003] In the previous scenario, the vehicle's impact mitigation system identifies a pedestrian and actively responds to the impact event. Active responses can be both external and internal. External responses could include, but are not limited to, bumper-mounted and hood-mounted airbags and hood-lift systems. Internal responses could include, but are not limited to, the activation of steering wheel, dashboard, and seatbelt airbags, or side curtain airbags.

[0004] On the other hand, if the vehicle impact mitigation system determines that the disputed impact is not a pedestrian, no external reaction is required, although one or more of the aforementioned internal reactions may still be ordered.

[0005] In practice, detecting a pedestrian impact requires complete sensor coverage of the vehicle's front end to minimize potential pedestrian injury and allow for impacts from other objects, not pedestrians, without system detection or response. One known method for achieving this is to use two pressure sensors at opposite ends of the vehicle's front end, connected by a sealed tube. However, this architecture is not the most cost-effective, as it requires a pressure sensor at each end of the tube.

[0006] Accordingly, there is a need for a simple, cost-effective device to detect the severity, location, and width of an impact. This information can be integrated by a control system with other sensor outputs to provide an intelligent collision mitigation system.

[0007] DE 10 2011 108 627 A1 discloses an impact sensor consisting of two deformable hollow bodies and a pressure sensor in each for detecting the pressure change in the respective hollow body,

[0008] As in so many areas of vehicle technology, there is always room for improvement regarding the protection of pedestrians in a pedestrian-vehicle collision event.

[0009] The invention is therefore based on the technical problem of providing an improved detection and injury mitigation system for a vehicle to identify an object in an impact event.

[0010] This problem is solved by a detection and injury attenuation system according to claim 1 and by a detection and injury attenuation system according to claim 6. The dependent claims relate to further embodiments of the invention. In particular, the prior art does not disclose any subject matter according to claim 1 or claim 6 with an impact sensor comprising a first and a second tube, wherein at least one section of each of the tubes has a common axis. BRIEF SUMMARY OF THE INVENTION

[0011] The disclosed inventive concept overcomes the problems associated with known impact detection systems. In particular, the disclosed inventive concept provides a detection and injury mitigation system for a vehicle to identify an object in an impact event, overcoming the limitations of known systems. Specifically, the system of the disclosed inventive concept includes an impact detection unit comprising an impact sensor and a pressure detection unit. The impact sensor comprises a first pipe section and a second pipe section. The pressure detection unit comprises a housing. Within the housing are a first pressure sensor and a second pressure sensor. One end of the first pipe section is fluidly connected to the first pressure sensor. One end of the second pipe section is fluidly connected to the second pressure sensor.The pipe sections are filled with a fluid, such as a gas. The pressure sensing unit detects a change in the fluid pressure in one or both of the pipe sections.

[0012] According to a first embodiment of the disclosed inventive concept, the first and second pipe sections form a loop pressure tube. In this embodiment, one of the pipe sections is located at the front of an energy absorber, and the other pipe section is located either at the top or the rear of the energy absorber. This ensures that, in the event of an impact, only the pipe section at the front of the energy absorber is crushed. As a result, one part of the loop tube absorbs the pressure wave caused by the impact, and the other part of the loop tube carries the pressure wave. If the distance between the crushed area and a sensor is small, the propagation of the pressure wave is relatively fast. If the distance between the crushed area and a sensor is large, the propagation of the pressure wave is relatively slow.By providing a sensor at each open end of the loop, a determination regarding the location of the impact at the front of the vehicle can be easily made.

[0013] According to a second embodiment of the disclosed inventive concept, the first pipe section and the second pipe section are separate pipes. In the first embodiment, the first and second pipe sections of the loop pressure pipe are straight and parallel. In the second embodiment, at least a portion of the first pipe section and at least a portion of the second pipe section share a common axis.

[0014] The system includes a control unit to which the pressure sensing unit is attached. The system also includes a deployable protective element to protect a person. This deployable protective element can be external, in the form of bumper-mounted and hood-mounted airbags and hood lift systems. Alternatively, the deployable protective element can be internal, in the form of one or more steering wheel, dashboard, and seatbelt airbags, or side / head airbags.

[0015] The above advantages and other advantages and features will become readily apparent from the following detailed description of the preferred embodiments when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For the purpose of a more complete understanding of this invention, reference will now be made to the embodiments which are shown in more detail in the accompanying drawings and are described below by means of examples of the invention, wherein: Fig. 1 a simplified perspective view of the front section of a motor vehicle which includes a pedestrian impact detection system according to a preferred embodiment of the disclosed inventive concept; Fig. 2 one of the Fig. 1. Similar view, but shows a top view of the front of the motor vehicle; Fig. 3 shows a view of the impact detection unit according to a preferred embodiment of the disclosed inventive concept, shown in relation to the bumper and energy absorber of a vehicle; Fig. 4 shows a sectional view along line 4-4 from Fig. 3 was undertaken; Fig. 5 is a top view of the impact detection unit according to an alternative embodiment of the disclosed inventive concept, which is positioned in the front section of a motor vehicle; Fig. Figure 6 shows a sectional view of an alternative embodiment of the arrangement of the pressure tube in relation to the energy absorber and the bumper of a vehicle, extending along line 6-6 of Fig. 5 was undertaken; Fig. 7 shows a top view of an alternative embodiment of the pedestrian impact detection system according to a preferred embodiment of the disclosed inventive concept; Fig. 8 a rear view of the pressure tubes attached to the energy absorber according to the embodiment of the in the Fig. 6 and Fig. 7 pedestrian impact detection systems are positioned; Fig. Figure 9 shows a sectional view of the assembly of pressure pipes and energy absorber, extending along line 9-9 from Fig. 8 was undertaken; and Fig. Figure 10 shows a sectional view of the assembly of pressure pipes and energy absorber, which extends along line 10-10 from Fig. 7 was carried out. DETAILED DESCRIPTION OF THE PREFERRED EXECUTION FORM

[0017] In the following figures, the same reference numbers are used to refer to identical components. The following description details various operating parameters and components for different designed embodiments. These specific parameters and components are included as examples and are not intended to be limiting.

[0018] The disclosed invention generally provides a detection and injury mitigation system for a vehicle which, by using a single housing for both pressure sensors, offers a more cost-effective solution compared to known technologies. In this way, a single connection to the pressure pipe and a single mounting component on the vehicle are provided.

[0019] The disclosed inventive concept works to determine a pedestrian impact based on the pressure wave generated at a specific point in the loop pressure tube by an impact. By using a pressure sensor attached to one open end of a leg of the loop pressure tube and another pressure sensor attached to the other open end of the other leg of the loop pressure tube, the difference in signal time and distance traveled can be measured, and the impact position can thus be determined. The measurement relies on the assumption that only one leg of the loop pressure tube experiences an impact, while the other leg is isolated and protected from impact by an energy absorber.

[0020] With reference to Fig. Figure 1 is a simplified perspective view of the front section of a motor vehicle, generally represented as Figure 10, which includes a pedestrian impact detection system according to a preferred embodiment of the disclosed inventive concept. With reference to Fig. 2 is one of the Fig. Figure 1 shows a similar view, but a top view of the motor vehicle 10. A bumper assembly 12 is shown in the foremost section of the vehicle 10. The bumper assembly 12 is covered by a relatively thin front fairing 14 to provide an aerodynamic profile and to enhance the appearance of the underlying bumper components. The shape and overall configuration of the vehicle 10 and the bumper assembly 12, which are shown in the Fig. 1 and Fig. The figures shown in 2 are for illustrative purposes only and are not intended to be restrictive.

[0021] In the vehicle 10, an energy absorber 16 is generally embedded between the bumper assembly 12 and the interior of the vehicle. The energy absorber 16 can be composed of a variety of materials, but preferably of an impact-resistant foam or a molded polymerized material. The energy absorber 16 is designed to absorb kinetic energy when the bumper assembly 12 experiences an impact event by being crushed, flattened, or otherwise deformed. The energy absorber 16 can be made of a variety of materials, including a foamed or a thin-walled polymerized material.

[0022] The bumper assembly 12 further includes a bumper 17. The bumper 17 is preferably, but not necessarily, made of an extruded metal, such as an aluminum extrusion. Alternatively, the bumper 17 can be made of a soft, rigid material.

[0023] Adjacent to and extending from the energy absorber 16 towards the interior of the vehicle is an impact detection unit 18. The impact detection unit 18 includes an impact sensor 20 and a pressure sensing unit 22. The pressure sensing unit 22 is attached to an electronic control unit 24. The electronic control unit 24 can receive a signal from the pressure sensing unit 22 indicating that an impact event has occurred, as determined by the extent of the pressure change in the impact sensor 20 of the impact detection unit 18, as discussed in more detail below.

[0024] The electronic control unit 24 is attached to other components of the vehicle 10's pedestrian protection system. For example, the electronic control unit 24 can be attached to hood lift actuators 26 and 26', which lift the vehicle's hood to create greater separation between the underside of the hood and rigid components beneath it. This additional separation allows the hood to deflect downwards under the impact of a pedestrian collision. Accordingly, signals from the electronic control unit 24 can trigger the hood lift actuators 26 and 26' to lift the hood at an appropriate time.

[0025] The hood lift actuators 26 and 26' are examples of active pedestrian protection. Other forms of pedestrian protection that could be triggered by the electronic control unit 24 include external airbags (not shown) for pedestrian protection.

[0026] It is possible that the type of impact determined by the electronic control unit 24 in response to the pressure sensing unit 22 is not a pedestrian impact, but rather an impact not involving a pedestrian. In such a case, the electronic control unit 24 would, if necessary, signal an internal airbag control module 28 to initiate the deployment of one or more interior airbags (not shown), including, but not limited to, dashboard and steering wheel airbags and head airbags. It is understood that the interior airbags can also be initiated in the event of a pedestrian impact.

[0027] With reference to Fig. The pressure sensing unit 22 includes a pressure sensing unit housing 23. The pressure sensing unit housing 23 contains a first pressure sensor 30 and a second pressure sensor 32. The impact sensor 20 includes a loop pressure tube 33 with a first leg or pressure tube section 34 and a second leg or pressure tube section 36. The loop pressure tube 33 and the associated pressure sensors 30 and 32 contain a fluid, such as a gas. The loop pressure tube 33 is preferably, but not necessarily, made of a flexible or semi-flexible polymerized material. Accordingly, the loop pressure tube 33 can be used in a wide variety of packaging options.

[0028] The pressure sensing unit 22 of the disclosed inventive concept may optionally include a bidirectional, self-testing accelerometer 35 for safety (to prevent system malfunction) and a temperature sensor 37. The temperature sensor 37, if provided, detects the temperatures of the fairing 14 and the energy absorber 16, insofar as the temperatures of these components are subject to changes in the ambient air temperature. The pressure sensing unit 22 may further include a piezoelectric transducer 39 for testing the pressure sensitivity of the loop pressure tube 33 by generating a pressure pulse. The piezoelectric transducer 39, if provided, checks the pressure sensitivity each time the vehicle is started.

[0029] The first pressure pipe section 34 includes an open end 38, while the second pressure pipe section 36 includes an open end 42. The first pressure pipe section 34 and the second pressure pipe section 36 are fluidically connected by a loop 44, such that the loop pressure pipe 33 is continuous between the first open end 38 and the first open end 42. The open end 38 of the first pressure pipe section 34 is fluidly connected to the first pressure sensor 30, while the open end 42 of the second pressure pipe section 36 is fluidly connected to the second pressure sensor 32.

[0030] The loop pressure tube 33 of the impact detection unit 18 is attached to the vehicle 10 by a mounting clamp 46 and the pressure sensor housing 22. The impact sensor 20 may also be attached to the vehicle 10.

[0031] With reference to Fig. 4 shows a sectional view of Fig. Figure 3, drawn along line 4-4 of this figure, shows the relative position of the first pressure pipe section 34, which is installed adjacent to the front of the energy absorber 16, while the second pressure pipe section 36 is installed on the top of the energy absorber 16. It should be noted that the second pressure pipe section 36 could also be installed on the bottom of the energy absorber 16.

[0032] An alternative to the one in the Fig. The arrangement shown and discussed in relation to figures 1 to 4 is in the Fig. 5 and Fig. 6 shown. Fig. Figure 5 shows a top view of the impact detection unit according to an alternative embodiment of the disclosed inventive concept, which is positioned in the front section of a motor vehicle, and Fig. Figure 6 shows a sectional view of the acquisition unit, which extends along line 6-6 from Fig. 5 was carried out.

[0033] Like the ones in the Fig. The embodiment of the pedestrian impact detection system shown in Figures 1 to 4 includes the components described in the Fig. 5 and Fig. In the embodiment shown in Figure 6, the vehicle 10 has the bumper assembly 12, which is covered by the thin front fairing 14. The bumper 17 is in turn part of the bumper assembly 12.

[0034] A loop pressure tube 48 with a first leg or pressure tube section 50 and a second leg or pressure tube section 52 is provided. The first pressure tube section 50 and the second pressure tube section 52 are connected by a loop 54. The open ends of the loop pressure tube 48 are fluidically connected to the pressure sensing unit 22 in the same manner as described above with respect to the Fig. The embodiment shown in Figures 1 to 4 is described. An energy absorber 56 is provided between the trim panel 14 and the bumper 17. Like the energy absorber 16 described above, the energy absorber 56 can be composed of a variety of materials, but preferably consists of an impact-resistant foam or a molded polymerized material.

[0035] As in the Fig. 5 and Fig. As shown in Figure 6, the first pressure pipe section 50 is installed adjacent to the front of an energy absorber 56, while the second pressure pipe section 52 is installed in a channel 58 formed on the rear of the energy absorber 52. In this way, the second pressure pipe section 52 is protected against direct impact.

[0036] The loop pressure tubes 33 and 48 discussed above represent one approach to the pressure tube of the impact detection unit of the disclosed inventive concept. However, this is not the only possible arrangement, and an alternative pressure tube configuration is described in the Fig. Numbers 7 to 10 are shown.

[0037] With reference to Fig. Figure 7 shows an alternative embodiment of the pedestrian impact detection system according to the disclosed inventive concept, which is generally represented as 60. The pedestrian impact detection system 60 includes a pressure assembly 62, which is generally positioned adjacent to an energy absorber 63, which itself is positioned adjacent to the trim 14. The bumper 17 is positioned adjacent to the pressure assembly 62.

[0038] The pressure assembly 62 comprises a pressure pipe system 64, which includes a first pressure pipe 66 and a second pressure pipe 68. The first pressure pipe 66 and the second pressure pipe 68 each contain a fluid, such as a gas. The pipe arrangement is in Fig. Figure 8 shows a rear view of the energy absorber 63 and the pressure tube system 64. A pressure sensor housing 70 is provided, which includes a first pressure sensor 72 and a second pressure sensor 74. The open end of the first pressure tube 66 is attached to the second pressure sensor 74, and the open end of the second pressure tube 68 is attached to the first pressure sensor 72.

[0039] Fig. Figure 9 shows a sectional view of the energy absorber 63, the first pressure tube 66, the second pressure tube 68, the first pressure sensor 72 and the second pressure sensor 74, which are located in the pressure sensor housing 70 (in the Fig. 7 and Fig. (shown in 8) are included. Fig. The section view shown in Figure 9 is along line 9-9 of Fig. 8. The pressure sensor housing 70 is installed in a recessed area 71 formed in the energy absorber 63.

[0040] Fig. 10, which runs along line 10-10 from Fig. Figure 7 shows a sectional view of the pedestrian impact detection system 60 according to the present embodiment. As shown, the first pressure tube 66 and the second pressure tube 68 are positioned behind the energy absorber 63, but in front of the bumper 17.

[0041] During operation, the impact detection unit reacts to an impact event by sending a signal to the electronic control unit 24. This signal is generated by the pressure detection unit 22 (or 22') and is itself a response to a change in pressure detected in the pressure tube 33 or in one or both pressure tubes 66 and 68. This is made possible by a pressure transducer (not shown) that is connected to the pressure sensor 30 (or 72) and the second pressure sensor 32 (or 74) and continuously generates an electrical or electronic signal representative of the detected pressure.The signals generated by the first pressure sensor 30 (or 70) and the second pressure sensor 32 (or 74) are sent to the electronic control unit 24, where they can be digitized, integrated, measured, compared, or otherwise processed electronically and / or mathematically to determine characteristics such as the magnitude, time, and location of an impact on the impact detection unit 18 (or 18' or 70). It is also understood that it may be possible to use the raw signals generated by the first pressure sensor 30 (or 72) and the second pressure sensor 32 (or 74) to actuate either a pedestrian protection element or a passenger protection element without significant processing by the electronic control unit 24.

[0042] The disclosed inventive concept provides for the packaging of the two pressure sensors 30 and 32 (or 72 and 74) adjacent to each other in the same pressure sensing unit housing 23 (or 70) and contributes to the efficiency of the design of the entire impact sensing unit 18 (or 18') compared to arranging multiple sensors at separate, spaced-apart locations. The manufacturing, installation, and maintenance of the impact sensing unit 18 (or 18') are all improved by the unified design of the pressure sensing unit 22 (or 22').

[0043] It is further described as follows: A. Detection and injury attenuation system for a vehicle to identify an object in an impact event, wherein the system comprises the following: an impact sensor comprising a first and a second tube, wherein at least one section of each of the tubes has a common axis; a first pressure sensor to which the first pipe is attached; a second pressure sensor to which the second pipe is attached; and a housing in which the sensors are located. B. Detection and injury attenuation system for a vehicle according to A, wherein the first tube includes a curved section and a straight section, and the second tube includes a curved section and a straight section, the straight sections having the common axis. C. Detection and injury attenuation system for a vehicle according to B, wherein the straight section of the first tube extends from the curved section of the first tube and the straight section of the second tube extends from the curved section of the second tube. D. Detection and injury attenuation system for a vehicle according to C, wherein the curved section of the first tube is connected to the first pressure sensor and the curved section of the second tube is connected to the second pressure sensor. E. Detection and injury attenuation system for a vehicle according to C, wherein a section of the curved section of the first tube overlaps with a section of the curved section of the second tube. F. Detection and injury attenuation system for a vehicle according to A, further comprising a bumper and an energy absorber, wherein the energy absorber has a front and a back, with the first and second tubes being installed adjacent to the back. G. Detection and injury attenuation system for a vehicle according to F, wherein the energy absorber has a pocket formed in the rear, the housing being built into the pocket. H. Detection and injury attenuation system for a vehicle according to F, wherein the energy absorber has a long axis and wherein the common axis shared by the sections of the tubes is parallel to the long axis of the energy absorber. I. Detection and injury mitigation system for a vehicle according to E, wherein the tubes are filled with a fluid and the pressure sensors detect changes in the fluid pressure in the first and second tubes. J. Detection and injury attenuation system for a vehicle to identify an object in an impact event, wherein the system comprises: an impact sensor comprising a first tube with a curved and a straight section and a second tube with a curved and a straight section; a first pressure sensor to which the first pipe is attached; a second pressure sensor to which the second pipe is attached; and a housing in which the sensors are located. K. Detection and injury attenuation system for a vehicle according to J, wherein the straight section of the first tube and the straight section of the second tube have a common axis. L. Detection and injury attenuation system for a vehicle according to J, wherein the straight section of the first tube extends from the curved section of the first tube and the straight section of the second tube extends from the curved section of the second tube. M. Detection and injury attenuation system for a vehicle according to J, wherein the curved section of the first tube is connected to the first pressure sensor and the curved section of the second tube is connected to the second pressure sensor. N. Detection and injury attenuation system for a vehicle according to J, wherein a section of the curved section of the first tube overlaps with a section of the curved section of the second tube. O. Detection and injury attenuation system for a vehicle according to J, further comprising a bumper and an energy absorber, wherein the energy absorber has a front and a back, with the first and second tubes being installed adjacent to the back. P. Detection and injury attenuation system for a vehicle according to O, wherein the energy absorber has a pocket formed in the rear, the housing being built into the pocket. Q. Detection and injury attenuation system for a vehicle according to P, wherein the energy absorber has a long axis and wherein the common axis shared by the sections of the tubes is parallel to the long axis of the energy absorber. R. Detection and injury mitigation system for a vehicle according to J, wherein the tubes are filled with a fluid and the pressure sensors detect changes in the fluid pressure in the first and second tubes. S. Detection and injury mitigation system for a vehicle to identify an object in an impact event, wherein the system comprises the following: an impact sensor that includes a first and a second tube; a first pressure sensor to which the first pipe is attached; a second pressure sensor to which the second pipe is attached; an energy absorber with a pocket and a housing for storing the pressure sensors, the housing being essentially built into the pocket. T. Detection and injury attenuation system for a vehicle according to A, wherein the first tube includes a curved section and a straight section extending therefrom, and the second tube includes a curved section and a straight section extending therefrom, the straight sections having the common axis.

Claims

[1] Detection and injury attenuation system for a vehicle (10) to identify an object in an impact event, characterized by , that the system includes the following: an impact sensor (20) comprising a first and a second tube (66, 68), wherein at least one section of each of the tubes (66, 68) has a common axis; a first pressure sensor (30) to which the first pipe (66) is attached; a second pressure sensor (32) to which the second tube (68) is attached; and a housing (23) in which the sensors are located. [2] Detection and injury mitigation system for a vehicle (10) according to claim 1, wherein the first tube (66) includes a curved section and a straight section and the second tube (68) includes a curved section and a straight section, wherein the straight sections have the common axis. [3] Detection and injury mitigation system for a vehicle (10) according to claim 2, wherein the straight section of the first tube (66) extends from the curved section of the first tube (66) and the straight section of the second tube (68) extends from the curved section of the second tube (68). [4] Detection and injury mitigation system for a vehicle (10) according to claim 3, wherein the curved section of the first tube (66) is connected to the first pressure sensor (30) and the curved section of the second tube (68) is connected to the second pressure sensor (32). [5] Detection and injury mitigation system for a vehicle (10) according to claim 3, wherein a section of the curved section of the first tube (66) overlaps with a section of the curved section of the second tube (68). [6] Detection and injury attenuation system for a vehicle (10) to identify an object in an impact event, characterized by , that the system comprises: an impact sensor (20) comprising a first tube (66) with a curved and a straight section and a second tube (68) with a curved and a straight section; a first pressure sensor (30) to which the first tube (66) is attached; a second pressure sensor (32) to which the second tube (68) is attached; and a housing (23) in which the sensors are located, wherein the straight section of the first tube (66) and the straight section of the second tube (68) have a common axis. [7] Detection and injury mitigation system for a vehicle (10) according to claim 6, wherein the straight section of the first tube (66) extends from the curved section of the first tube (66) and the straight section of the second tube (68) extends from the curved section of the second tube (68). [8] Detection and injury mitigation system for a vehicle (10) according to claim 6, wherein the curved section of the first tube (66) is connected to the first pressure sensor (30) and the curved section of the second tube (68) is connected to the second pressure sensor (32). [9] Detection and injury mitigation system for a vehicle (10) according to claim 6, wherein a section of the curved section of the first tube (66) overlaps with a section of the curved section of the second tube (68).

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