Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
  • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
  • G01V3/15—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for use during transport, e.g. by a person, vehicle or boat
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
  • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
  • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
  • G01V3/088—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices operating with electric fields
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
  • B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
  • B60R19/48—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects combined with, or convertible into, other devices or objects, e.g. bumpers combined with road brushes, bumpers convertible into beds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
  • B60W40/02—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to ambient conditions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R19/00—Wheel guards; Radiator guards, e.g. grilles; Obstruction removers; Fittings damping bouncing force in collisions
  • B60R19/02—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects
  • B60R19/48—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects combined with, or convertible into, other devices or objects, e.g. bumpers combined with road brushes, bumpers convertible into beds
  • B60R19/483—Bumpers, i.e. impact receiving or absorbing members for protecting vehicles or fending off blows from other vehicles or objects combined with, or convertible into, other devices or objects, e.g. bumpers combined with road brushes, bumpers convertible into beds with obstacle sensors of electric or electronic type

Definitions

• Proximity detection device for a motor vehicle
• the present invention relates to a device for detecting the presence of an object in a detection zone near a motor vehicle by measuring a capacity variation caused by the presence of said object.
• the invention also relates to a bumper comprising such a detection device, as well as to a motor vehicle comprising such a bumper.
• Such devices are known and allow for example to assist the driver to park his motor vehicle by informing him of the proximity of the obstacles surrounding the vehicle. In general, such a device informs the driver of the presence of obstacles around the vehicle when driving.
• the known devices of the "capacitive" type comprise one or more detection plates functioning as an oscillating circuit. A measurement of the capacitance between the detection plate (s) and the earth is made. The objects entering the detection zone of the device cause a variation of the measured capacity, for example an increase in the capacity, which makes it possible to determine the presence of the object and to evaluate its distance with respect to the vehicle as a function of the variation of the capacity between the plate (s) and the earth.
• Such devices can detect the presence of obstacles only when the vehicle and the obstacle are moving relative to each other, that is to say when the obstacle moves relative to each other. to a stationary vehicle or when the vehicle is moving in relation to a fixed obstacle or when the vehicle and the obstacle are moving. If the obstacle and the vehicle are fixed relative to each other, the measured capacity is constant and the obstacle is not detected.
• the invention aims to overcome these disadvantages by providing a detection device for detecting moving obstacles and obstacles. fixed with respect to the vehicle and providing an enlarged detection area compared to existing devices.
• the invention relates to a detection device of the aforementioned type, comprising an emission element of an electric field, an element for receiving an electric field disposed at a distance from the emission element, and means for measuring the coupling capacitance between the transmitting element and the receiving element, the transmitting element emitting an electrical signal which is then received by the receiving element so that a coupling capacitance a predetermined value is established between the transmitting element and the receiving element when no object is present in the detection zone, a variation of the coupling capacitance between the transmitting element and the receiving element indicating the movement of an object in the detection zone and restoring a capacitance of a value different from the predetermined value indicating the presence of a static object in the detection zone.
• Measuring the capacitance between a transmitter element and a receiver element provides information on moving obstacles and fixed obstacles relative to the vehicle. Indeed, when an obstacle is in motion and approaches the vehicle, the measured capacity increases, as for known devices, and when the obstacle is fixed, the capacity is established at a value different from that which is measured when no obstacle is present in the detection zone contrary to the known devices. Thus, a variation of the capacitance indicates the presence of a moving obstacle, while a capacitance of a value different from the capacitance measured without obstacle indicates a fixed obstacle.
• the detection of a fixed obstacle is particularly advantageous, for example when the vehicle is parked and an obstacle could damage the vehicle when opening the vehicle doors.
• the detection of fixed obstacles is also advantageous before committing the movement of the vehicle, for maneuvers in forward or reverse.
• the detection zone is enlarged because it is easier to supply the emission element with large AC voltages, which makes it possible to have a large signal-to-noise ratio at the receiving element and thus to increase the sensitivity of the device to large distances.
• the electric field extending between the transmitting element and the receiving element has a semicircular shape, which provides a more detection area oriented towards a zone of interest of obstacle detection. According to other characteristics of the detection device:
• the detection device comprises a second emission element and a second element for receiving an electric field, said pair of elements being arranged to calibrate the detection device with respect to the ground and to carry out complementary measurements with the first transmission and reception elements;
• the two pairs of transmission and reception elements are arranged to operate at different frequencies
• the transmission element transmits a modulated signal
• the reception element or a control electronics comprising a synchronous demodulation device making it possible to demodulate the signal received by the reception element
• the detection device comprises a signal generator transmitting a square or sinusoidal signal to the transmission element and a square signal to the demodulation device of the reception element;
• the detection device comprises calculation means arranged to determine the distance of the object with respect to the motor vehicle as a function of the capacitance or the capacitance variation measured on the two pairs of transmission and reception elements.
• the invention also relates to a motor vehicle bumper comprising a detection device as described above. According to other features of the bumper:
• the emission element is fastened to an internal transverse end portion of the bumper and the receiving element is arranged at the other internal transverse end portion of the bumper;
• the emission element and the receiving element are embedded in the material of the bumper;
• the second transmission and reception elements are arranged under the first transmission and reception elements of the detection device.
• the bumper comprises at least one conductive or partially conductive surface disposed on the bumper and interposed between the emission element and the receiving element of the detection device, said surface being connected to the ground of said detection device.
• the invention also relates to a motor vehicle comprising a bumper as described above.
• the motor vehicle comprises a second bumper as defined above, one of the bumper being attached to the front of the motor vehicle and the other bumper being attached to the vehicle. rear of said vehicle.
• FIG. 1 is a schematic representation of a bumper of a motor vehicle comprising a detection device according to the invention
• FIG. 2 is a schematic representation of an equivalent electrical circuit illustrating the operation of the detection device according to the invention when no object is present in the detection zone
• FIG. 3 is a schematic representation of an equivalent electrical circuit illustrating the operation of the detection device according to the invention, when an object is present in the detection zone.
• FIG. 1 With reference to FIG. 1, there is described a bumper 1 intended to be fixed to the front or rear of a motor vehicle (not shown). It should be noted that the invention applies both to the front and to the rear of the vehicle, the detection device of the invention being particularly advantageous when it is installed at the front and at the rear of the vehicle. vehicle to provide a larger detection area.
• the inner face 2 of the bumper 1 is visible.
• the detection device described here can also be applied to the sides of the vehicle, in particular in the side rods, in order to further increase the detection zone. Lateral detection is then achieved by coupling and combining the front, rear and side devices.
• a detection device 4 is shown schematically in FIG. 1.
• This device comprises a transmission element 6 of an electric field, a receiving element 8 of an electric field and a control electronics 10, not shown in detail.
• the emission element 6 is fixed, for example glued, to a transverse end portion 12 of the inner face 2 of the bumper 1, in an upper zone thereof.
• the receiving element 8 is fixed, for example bonded, to the other transverse end portion 14 of the inner face 2 of the bumper, in an upper zone thereof.
• These elements 6 and 8 comprise a conductive material on at least one of their faces or on both their faces.
• the elements 6 and 8 may also be conductive surfaces applied to the inner or outer surface of the bumper or other element of the motor vehicle.
• the elements 6 and 8 can also be embedded in the material of the part to which they are secured. According to one embodiment, the elements 6 and 8 are each formed of a plurality of transmission and reception elements.
• the emission element 6 is connected to the control electronics 10 so as to emit an electric field which will then be received by the receiver element 8.
• the emission element 6 is arranged to emit square modulated electrical signals or sinusoidal.
• the control electronics 10 comprises a signal generator (not shown) transmitting a square or sinusoidal signal to the transmission element 6.
• the emitted signal has, for example, a voltage of a substantially peak-to-peak amplitude. equal to 20V.
• the signal emitted by the transmission element 6 operates for example at a frequency of between 50 KHz and 200 KHz. It will be understood that other frequencies can be used by adapting the control electronics 10.
• the modulation of the emitted signal makes it possible to distinguish it from other surrounding signals, for example coming from devices for detecting other vehicles or the like, so that the receiving element 8 processes the signal emitted by the transmitting element 6 and not another. This avoids the processing of spurious signals.
• the receiving element 8 is arranged to receive the electrical signal emitted by the transmission element 6 and to demodulate it synchronously or to transmit the received signal to the control electronics in charge of the synchronous demodulation in order to extract the signal from the surrounding noise.
• the reception element 8 or the control electronics 10 comprises a synchronous demodulation device (not shown), known in itself, which receives a square signal from the signal generator of the signal generator.
• the signal transmitted to the demodulation device has the same frequency as the signal transmitted to the transmitter element, that is to say between 50 KHz and 200 KHz according to the example mentioned above.
• the receiving element 8 is for example made using an inverting amplifier associated with a tuned circuit.
• the output is connected to the demodulation device, itself connected to a low-pass filter.
• the tuned circuit limits the bandwidth of the receiving element to the frequency of interest of the received signal. This eliminates the large noise components that could disturb the measurement.
• the demodulation device and the low-pass filter act as a narrow-band filter. Synchronous demodulation makes it possible to obtain a very important signal-to-noise ratio, which makes it possible to receive the transmitted signal even when it is very weak. The detection distance can thus be increased, as will be described later.
• the control electronics 10 comprises means for measuring the coupling capacitance between the transmitting element 6 and the receiving element 8 from the signal emitted by the transmitting element 6 and the signal demodulating by the synchronous demodulation device.
• the operation of the device described above is the following: - when no obstacle is in the detection zone, that is to say the emission zone of the electric field by the element of emission, the transmitting element 6 and the receiving element 8 are equivalent to two capacitors in series, respectively Ci and C 2 .
• the coupling capacitance C as shown in FIG. 2, between the transmitting element 6 and the receiving element 8 then has a predefined fixed value measured by the measuring means.
• the device when an obstacle enters the detection zone, it is equivalent to a capacitor C3 connected on the one hand to earth and connected on the other hand between the capacitor Ci of the emission element 6 and the capacitor C 2 the receiving element 8, as shown in FIG. 3.
• the measured coupling capacity varies.
• the coupling capacity is equal to a value different from the preset fixed value measured when no obstacle is in the detection zone.
• the device makes it possible to determine the presence of a fixed or moving obstacle in the detection zone.
• a transmitting element and a receiving element Due to the use of a transmitting element and a receiving element, it is possible to supply the transmission element with large voltages, which improves the quality of the transmitted signal.
• the use of synchronous demodulation optimally isolates the signal received from the noise.
• the transmission elements 6 and reception 8 can operate alternately by means of an electronic tilt device. These elements can also operate in purely capacitive elements.
• the detection device 4 comprises a second pair of transmission elements 16 and reception elements 18.
• This second pair of elements 16 and 18 also makes it possible to calculate the distance of an object in the detection zone and its position.
• the control electronics 10 comprises calculation means arranged to determine the distance of the obstacle with respect to the bumper 1 as a function of the signals emitted by the transmission elements 6 and 16 and received and by the elements of FIG. reception 8 and 18.
• the second pair of elements has the same structure and operates according to the same principle as the transmission element 6 and the receiving element 8 described above.
• the signal generator of the control electronics transmits signals at a different frequency to the second pair. This frequency is also for example between 50 KHz and 200 KHz.
• each pair operates independently of each other and the signals are not mixed.
• the second transmission elements 16 and receiving 18 are each arranged at an end portion 12, 14 of the bumper under the transmission elements 6 and receiving 8. This second pair makes it possible to calibrate the first pair while carrying out the measurement. variations in the ground level so that the driver is not informed of these variations when determining the presence of an obstacle in the detection zone.
• a layer of "primer”, or “primer” or “primer”, conductive is deposited on the bumper to ensure better adhesion of paint or a particular orientation of color particles .
• the presence of this layer may have the consequence that the transmission element 6 transmits a signal to the reception element 8 directly through the primer layer without substantially sending a signal to the outside of the vehicle, which can deteriorate the detection performance of the detection device 4.
• a conductive or partially conductive surface 20 is disposed on the inner face of the bumper 1 between the emission element 6 and the receiving element 8. This surface 20 is connected to the ground of the control electronics.
• the surface 20 extends for example over the entire height of the bumper and is also interposed between the second transmission element 16 and receiving 18.
• the detection device 4 described above comprises an information device of the driver of the vehicle informing it of the presence of a moving or fixed obstacle around the motor vehicle. This device can also inform the distance of this obstacle relative to the vehicle. This device informs the driver as a function of the signal emitted by the detection device, this signal indicating whether a variation of the coupling capacity or an establishment of a capacity of a different value occurs.
• the transmitting and receiving elements may also be disposed on the outer face of the bumper or integrated within the bumper material as previously described. According to other embodiments, the transmitting and receiving elements can be placed on other parts of the vehicle, such as shock absorbers, side sticks, beams, bands, etc.
• the detection device described above is particularly advantageous because it makes it possible to have a large detection zone around the motor vehicle, particularly if two devices are used, namely one at the front of the vehicle and the other at the vehicle. back. In addition, it can detect both moving obstacles and fixed obstacles.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Remote Sensing (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geophysics (AREA)
• General Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Geology (AREA)
• Mechanical Engineering (AREA)
• Electromagnetism (AREA)
• Transportation (AREA)
• Mathematical Physics (AREA)
• Automation & Control Theory (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Radar Systems Or Details Thereof (AREA)
• Geophysics And Detection Of Objects (AREA)
• Emergency Alarm Devices (AREA)
• Switches That Are Operated By Magnetic Or Electric Fields (AREA)
• Traffic Control Systems (AREA)

Applications Claiming Priority (2)

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• 2008
  • 2008-06-06 FR FR0853781A patent/FR2932281B1/fr active Active
• 2009
  • 2009-06-05 EP EP09772701A patent/EP2310881A2/de not_active Withdrawn
  • 2009-06-05 MX MX2010013417A patent/MX2010013417A/es active IP Right Grant
  • 2009-06-05 KR KR1020117000358A patent/KR101551263B1/ko not_active IP Right Cessation
  • 2009-06-05 CN CN2009801282981A patent/CN102099707A/zh active Pending
  • 2009-06-05 US US12/996,476 patent/US8791801B2/en not_active Expired - Fee Related
  • 2009-06-05 WO PCT/FR2009/051063 patent/WO2010001019A2/fr active Application Filing
  • 2009-06-05 JP JP2011512187A patent/JP2011526677A/ja active Pending

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