JP2008191098A - Light projection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light projection device for a radar device capable of emitting a beam correctly in a target projection direction. <P>SOLUTION: The projection direction of projection light 61 radiated from a laser diode 31 is set by a projection lens 37 moved by an actuator 40. The position of the projection lens 37 is detected by position detectors 43a, 43b. The projection direction of projection light 61 is followed by movement of the projection lens 37 by movement of the actuator 40 by a scanner control part 25. The scanner control part 25 controls the actuator 40 so that the projection lens 37 is stopped at each position corresponding to a plurality of prescribed directions, while moving the projection lens 37 so that the projection light 61 can scan a prescribed direction range. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light projecting device for an on-vehicle optical radar device that generates a light beam from a light source such as a laser beam, receives reflected light from a target object, and detects a distance from the target object. The present invention relates to an apparatus for controlling the direction of incident light.

  In recent years, efforts have been made to develop technologies aimed at improving driver safety when driving a car. As one of the means, an apparatus for detecting position information of an object existing in front of a preceding vehicle and an automobile using a radar has been put into practical use. Specifically, based on the position detection information of the vehicle front object obtained by the radar device, safety support such as collision avoidance with the vehicle ahead is performed during traveling.

  Various radar systems have been proposed at present, and it is required that sufficient detection performance be obtained while suppressing apparatus costs. Among them, an optical radar device that scans a laser beam and detects an object has been put into practical use.

  For example, as described in Patent Document 1 below, an optical radar scanner device scans a laser beam at a predetermined angle and projects it toward a front object, and detects reflected light generated by the object with a light receiver. There has been proposed an apparatus for calculating the position of a front object by detecting a time difference until light reception is detected.

  FIG. 7 is a block diagram showing a configuration of a conventional optical radar device described in Patent Document 1 below.

  In FIG. 7, the object detection apparatus 1 includes a light projecting unit 2, a light receiving unit 3, an offset position storage circuit 5, and a CPU 4 to which a plurality of tilt sensors 6 are connected. Then, the light that is driven by the oscillation circuit 11 in the light projecting unit 2 and is emitted from the light emitting element 12 is moved in the horizontal or vertical direction by the lens 13, the actuator 14, and the actuator (ACT) driving circuit 15. Change the direction of the projected light.

The CPU 4 gives an instruction of an actuator driving amount necessary for moving the lens 13 to a position corresponding to the projection direction. The lens 13 is scanned by giving an instruction to the ACT driving circuit 15 to sequentially increase or decrease the driving amount of the actuator 14. During scanning of the projection lens 13, projection light is output from the light emitting element 12 via the oscillation circuit 11 from the CPU 4. The reflected light is detected by the light receiving lens 17, the light receiving element 18, and the detection circuit 19 to detect the object.
JP 2002-162470 A

  The above-described light projecting device of a radar apparatus is a method of continuously scanning an outgoing beam by continuously moving a projection lens to a position corresponding to a target projection direction, and emitting a light beam at regular intervals. It is. In the light projecting device in the radar device of Patent Document 1, the projection lens position and the corresponding emission beam angle are estimated from the actuator drive instruction. For this reason, the position of the projection lens that actually exists cannot be detected in real time. Therefore, an abnormality cannot be detected when a vibration disturbance during driving of the automobile is applied to the projection lens and the position of the projection lens deviates from the indicated position.

  In addition, since the beam is emitted even when the position deviation of the light source occurs, there has been a problem that an erroneous ray projection is performed on an object existing in a direction other than the target direction.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light projecting device in a radar device that can correctly emit light rays in a target projection direction.

  That is, the invention described in claim 1 is a light projecting device that projects a light beam emitted from a first light source onto an object, an optical element that sets a projection direction of the light beam emitted from the first light source, An actuator for moving the optical element; position detecting means for detecting the position of the optical element; and direction control means for designating a projection direction of the light beam and controlling the optical element to follow and drive the optical element. The direction control means controls the actuator to stop the optical element at a position corresponding to a plurality of predetermined directions while moving the optical element so that the light beam can scan a predetermined direction range. It is characterized by that.

  According to the first aspect of the present invention, the position of the projection optical element is stopped by feedback control, and a pulse is emitted at the time of stop, so that a constant projection direction can be maintained against disturbance such as vibration. And the position resolution of the detection signal can be improved.

  According to a second aspect of the present invention, in the first aspect of the present invention, the direction control means controls the actuator so that the light beam can move vertically and horizontally.

  According to the second aspect of the present invention, it is possible to detect the vertical / horizontal position information of the object by controlling the movement of the projection optical element in the vertical and horizontal directions and scanning the projection light beam in the vertical and horizontal directions.

  According to a third aspect of the present invention, in the first aspect of the present invention, when the deviation from the projection direction is detected by the position detecting means and is within a predetermined range, the light source emits light. When the projection direction is out of a predetermined range, the light source is notified of light emission stop.

  According to the third aspect of the invention, when the projection direction exceeds the predetermined range, by stopping the light emission, it is possible to prevent erroneous detection that occurs due to erroneous light emission in a direction other than the target projection angle.

  The invention according to claim 4 is the invention according to claim 1, wherein the position detecting means includes a second light source, a light receiving position detecting element, and a slit interlocking with the optical element. A detection output of the optical element position is obtained.

  According to the invention described in claim 4, by always detecting the actual position of the projection optical element, it becomes possible to confirm and project the presence of the projection optical element at the position corresponding to the target projection direction. The projection angle accuracy can be improved.

  The invention according to claim 5 is a first light source that emits a predetermined light beam, a movable optical element for setting a projection direction of the light beam emitted from the first light source, and the first light source. An actuator for moving the optical element two-dimensionally in a direction perpendicular to the optical axis direction of the first light source in order to change the projection direction of the light beam emitted from the light source and scan a predetermined range; The position detection means for detecting the position of the optical element and the projection direction of the light beam are specified, and the optical element is driven and controlled by the actuator so that the light beam can scan the predetermined range. Direction control means for controlling the actuator so as to stop the light beam at a position corresponding to a plurality of predetermined directions while moving the optical element.

  According to the fifth aspect of the present invention, the position of the projection optical element is stopped by feedback control, and a pulse is emitted at the time of stop, so that a constant projection direction can be maintained against disturbance such as vibration. And the position resolution of the detection signal can be improved.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the direction control means is configured such that the light beam is movable in a plane direction perpendicular to the optical axis direction of the first light source. The above actuator is controlled.

  According to the sixth aspect of the present invention, the projection optical element is controlled to move in a plane direction perpendicular to the optical axis direction of the first light source, and the projection light beam is also scanned in the same direction. The distance to the object can be detected.

  The invention according to claim 7 is the invention according to claim 5, wherein the direction control means detects a deviation from the projection direction by the position detection means, and the projection direction is within the predetermined range. In the case of outside, the first light source is notified of light emission stop.

  According to the seventh aspect of the present invention, when the projection direction exceeds the predetermined range, by stopping the light emission, it is possible to prevent erroneous detection caused by erroneous light emission in a direction other than the target projection angle.

  The invention according to claim 8 is the invention according to claim 5, wherein the direction control means detects a deviation from the projection direction by the position detection means, and the projection direction is within the predetermined range. If the light source is within, the first light source is notified that the light emission operation is possible.

  According to the invention described in claim 8, when the projection direction is within the predetermined range, it is possible to emit light safely by notifying that light emission is possible.

  The invention according to claim 9 is the invention according to claim 5, wherein the position detecting means includes a second light source different from the first light source, a light receiving position detecting element, and an optical element. A slit that moves in conjunction with the movement; and a light receiving position detecting element that detects light emitted from the second light source through the slit and detects the position of the optical element. .

  According to the ninth aspect of the present invention, by always detecting the actual position of the projection optical element, the presence of the projection optical element can be confirmed and projected at a position corresponding to the target projection direction. Thus, the projection angle accuracy can be improved.

  In the light projecting device of the present invention, the light beam generated by the light source is incident on the optical element, and the light transmitted through the optical element is projected toward the target object. The optical element refracts incident light and emits it as projection light according to the amount of positional deviation between the center position of the incident light and the center position of the optical element. This projection light is projected in a direction shifted by the refraction angle with respect to the traveling direction of the incident light. The refraction angle increases as the amount of positional deviation between the center position of incident light and the center position of the optical element increases. Then, by moving the optical element in the vertical and horizontal directions, the direction of the projection light can be directed in a desired direction in both the horizontal direction and the vertical direction.

  The amount of movement of the optical element is set in proportion to the angle in the direction in which the projection light is to be directed. The control unit outputs a movement instruction to the optical drive unit according to the movement amount, and moves the optical element. In the moving position detecting element, the light beam from the second light source is incident on the slit that moves in conjunction with the optical element, and the spot center position of the transmitted light to the slit is detected, so that the moving amount of the optical element is reduced. Detected. Then, the control unit performs feedback control so that the optical element is moved in the direction of correcting the deviation with respect to the deviation between the detected position and the target movement value. When the movement is completed so that the deviation between the target position of the optical element and the detected position is within a predetermined range, the optical element is controlled to be held at the target position, and from the control unit to the light source control device, Notification is made.

  In the light source control device, upon receiving a notification from the control unit, the light beam is emitted, the reflected light from the target object is detected, and the distance to the target object is detected from the time difference from the projection to the light reception. After performing the distance detection, the optical element is moved to the next movement position. Next, scanning is performed by repeating movement, stop, and light projection.

  In addition, control is performed to hold the position of the optical element at a predetermined position at the time of beam emission and reception, but if the optical element position is out of the predetermined range due to vibration during driving of the automobile, light is emitted to the beam control device, Notification of light reception stop. As a result, it is possible to prevent erroneous detection due to beam emission and light reception operations outside the target direction.

  ADVANTAGE OF THE INVENTION According to this invention, the light projection apparatus in the radar apparatus which can emit a light ray correctly in the target projection direction can be provided.

  Even when a disturbance such as vibration is applied during light beam scanning by the light projecting device of the present invention, the light is correctly projected in the target projection direction without accidentally projecting in a direction deviating from the target. Can be projected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block configuration diagram showing the overall configuration of a laser radar to which the light projection device of the present invention is applied.

  In FIG. 1, this laser radar forms a light output of a laser control unit 21 that controls the operation of the entire laser radar and a laser diode 31 that is a light emitting element into a beam, and lenses 32 and 33 that are optical elements. And 37, the scanner unit 24 that projects the beam at an arbitrary angle, the output of the position detector of the scanner unit 24 and the target angle indicated by the laser control unit 21 are compared to control the amount of movement of the lens. The scanner control unit 25, a light receiving unit 27 that detects reflected light from the target object 62, and a laser light emitting device 23 that controls the light emitting operation of the laser diode 31 are configured.

  The laser control device 21 instructs to emit light to the laser light emitting device 23, detects reflected light from the target object 62 in the light receiving unit 27, instructs the target angle of the beam projection direction to the scanner control unit 25, and angle offset. An instruction signal is output and a movement completion signal of the scanner unit 24 is input.

  The scanner unit 24 supports a laser diode 31 and relay lenses 32 and 33 fixed in the lens holder 30 and a projection lens 37 for scanning light projected from the laser diode 31 as a first light source. A member 36, a plurality of wire springs 35 connecting the lens holder 30 and the support member 36, and driven members 38 a and 38 b on both sides of the support member 36 for moving the projection lens 37 together with the support member 36. An actuator 40 that directly moves the driven members 38a and 38b, and light sources 41a and 41b and position detectors 43a and 43b, which are second light sources for detecting the positions of the driven members 38a and 38b. Composed.

  In the scanner unit 24, relay lenses 32 and 33 are used to shape the light output from the laser diode 31 into a beam suitable for a laser radar having an appropriate divergence angle. The laser diode 31 emits light by driving the laser light emitting device 23 in accordance with a laser light emission command from the laser control unit 21. The beam projected from the laser diode 31 through the relay lenses 32 and 33 is further projected to the outside of the laser radar through the projection lens 37 mounted on the support member 36.

  The support member 36 is moved in the two-dimensional direction of the horizontal direction (X direction) and the vertical direction (Y direction) together with the driven members 38a and 38b by the actuator 40. Thereby, since the projection lens 37 mounted on the support member 36 is moved in the two-dimensional direction, the beam refracted by the projection lens 37 can be scanned two-dimensionally.

  The driven members 38a and 38b are formed with two slits 39a and 39b extending in the X direction and the Y direction, respectively. Light sources 41a and 41b and position detectors 43a and 43b are disposed on both sides of the driven members 38a and 38b with the slits 39a and 39b interposed therebetween. Although not shown, the position detectors 43a and 43b are composed of photoelectric conversion elements such as PSD (Position Sensing Device) and divided photodiodes.

  The movement of the support member 36 by the actuator 40 is detected by two position detectors provided independently, a position detector 43a that detects movement in the X direction and a position detector 43b that detects movement in the Y direction. And sent to the scanner control unit 25. In this embodiment, since optical position detectors, such as PSD, are used, the light sources 41a and 41b which irradiate each position detector 43a and 43b are arrange | positioned. The light sources 41a and 41b generally use light emitting diodes (LEDs) or laser diodes.

  As shown in FIG. 2, the projection lens 37 and the support member 36 can move in the vertical direction (Y direction) and the horizontal direction (X direction) in a plane perpendicular to the optical axis, and the actuator 40. However, when the projection lens 37 is driven in the direction of moving from the neutral position, a restoring force is applied in the direction opposite to the moving direction by the wire spring 35. The projection lens 37 is held at a position where the driving force of the actuator 40 and the restoring force of the wire spring 35 are balanced.

  The projection lens 37 has a characteristic of emitting with a refraction angle proportional to the amount of deviation of the incident position of the light beam with respect to the lens center. Although not shown, the actuator 40 is composed of an electromagnetic actuator such as a boil coil motor, and the driving force is applied in the horizontal and vertical directions by the attraction and repulsion action of the magnetic field generated by the current supplied to the electromagnetic coil and the magnetic field by the permanent magnet. Arise.

  On both side surfaces of the support member 36 of the projection lens 37, the driven members 38a and 38b are disposed as described above, and slit-shaped light guide members (slits) 39a and 39b are formed, respectively. The 2nd light sources 41a and 41b are arrange | positioned in the position used as the front of each slit 39a and 39b. Light rays emitted from the second light sources 41a and 41b enter the slits 39a and 39b, and the transmitted light rays 42a and 42b enter the position detectors 43a and 43b, respectively.

  As the projection lens 37 moves, the center positions of the transmitted lights 42a and 42b of the slits 39a and 39b change, and the incident spot positions on the position detectors 43a and 43b change. The position detectors 43 a and 43 b receive the incident spot light to convert the movement amount of the projection lens 37 into an electrical signal, and output a detection position signal corresponding to the position of the projection lens 37 to the scanner control unit 25. To do.

  The scanner control unit 25 which is a direction control unit receives a target angle instruction value and an angle offset instruction from the laser control unit 21 and converts them into a moving position of the projection lens 37, and position detectors 43a and 43b. A position sensor calculation unit 51 that calculates the amount of movement of the projection lens 37 from the detection signal, a position deviation detection unit 46 that detects the difference between the position indication value and the position detection result, and a determination unit 47 that compares and determines the amount of positional deviation. The linear motor driver 50 supplies driving power to the actuator 40, and the control calculation unit 48 provides a driving instruction to the linear motor driver 50 based on the positional deviation amount.

  The determination unit 47 is for determining whether or not the positional deviation of the projection lens 37 is within a predetermined range, and outputs the determination result to the laser control unit 21.

  The laser light emitting device 23 turns on and off the laser diode 31 with a predetermined pulse time width according to an instruction from the laser control unit 21. The light beam L1 emitted from the laser diode 31 is transmitted through the relay lenses 32 and 33 to obtain a parallel light beam L2. The parallel light beam L <b> 2 is incident on the projection lens 37, and the projection light 61 that passes through the projection lens 37 is irradiated toward the target object 62. The projection light 61 is a light beam in which the light beam is refracted in the direction of arrow A in FIG. 1 due to the relationship between the optical axis center of the parallel light beam L2 and the incident position of the projection lens 37, and the projection lens 37 is moved in the horizontal direction (X direction). By moving in the vertical direction (Y direction), the projection direction of the emitted light is scanned two-dimensionally in the horizontal direction (Ax direction shown in FIG. 2) and the vertical direction (Ay direction shown in FIG. 2).

  The projection light 61 is applied to the target object 62, and the reflected light 63 reflected here is incident on the light receiving lens 55 in the light receiving unit 27, and the light receiving sensor 56, which is a light detection element, changes the reflected light intensity with time. Is detected. Then, the detected light reception detection signal is output to the laser control unit 21.

  Next, the relationship between the moving direction of the projection lens 37 and the direction of the projection light 61 will be described with reference to FIG.

  When the projection lens 37 is translated in the left-right direction (arrow B direction in the figure), the projection direction in the horizontal direction (Ay direction in FIG. 2) can be changed according to the amount of movement. Similarly, when the projection lens 37 is translated in the vertical direction (arrow C direction in the figure), the projection direction in the vertical direction (Ay direction in the figure) can be changed according to the amount of movement.

  The amount of change in projection angle is proportional to the amount of movement of the projection lens 37 left and right and up and down. The target movement amount of the projection lens 37 is calculated from the target projection direction, the projection lens 37 is driven by the actuator 40, and the movement is controlled so as to coincide with the target position, thereby controlling the projection direction.

  The scanning angle in the horizontal and vertical directions is controlled so as to scan within the irradiation range 65 shown in FIG.

  Next, the projection lens moving operation and the light source emission control timing will be described with reference to the timing charts of FIGS.

  FIG. 3 is a timing chart for explaining the projection lens movement control operation and the light source emission control timing of the laser radar in this embodiment, and FIG. 4 is the projection lens movement timing in the horizontal and vertical directions, and the laser. 5 is a timing chart showing pulse emission timing.

  In FIG. 3A, the horizontal axis represents time, the vertical axis represents the projection lens position and the corresponding projection angle, and the position control instruction curve E and control during the position control operation of the projection lens 37 of the scanner control unit 25 are controlled. The time change of the position response curve F is shown. FIG. 3A shows the control target position and control position response when the projection lens position is moved to the target lens position 1 and stopped and then moved from the target lens position 1 to the target lens position 2 and stopped. ing.

  The graph of FIG. 3B shows the timing of the movement trigger signal, movement completion signal, projection light emission, and reception signal transmitted and received by the scanner control apparatus. The movement trigger signal is a logic signal that is output from the laser control unit 21 to the scanner control unit 25, and starts when the logic of the signal is switched from the “L” level to the “H” level. The position instruction is changed to the target position, and the projection lens 37 is moved to the target position. As for the movement completion signal, the scanner control unit 25 detects the position of the projection lens 37 and sets the “H” level when the deviation from the target position is within a predetermined range, and the “L” level when the deviation is outside the range. The logic signal is output to the laser controller 21.

  When the movement completion signal outputs “H” level, the laser control unit 25 changes the movement trigger signal logic from “H” level to “L” level, assuming that the projection lens position has reached the target position. When the scanner controller 25 notifies the movement completion signal of “H” level, the laser diode 31 is allowed to project light. The laser controller 21 receives the light projection permission and detects the laser emission and the reflected light at the timing shown in FIG.

  After detecting the laser pulse emission and the reflected light, the laser control unit 21 instructs the target position of the next projection lens 37 to the lens position 2 (in FIG. 3) to the scanner control unit 25 and moves it. The logic of the trigger signal is output from “L” level to “H” level. Upon receiving the signal, the scanner control unit 25 starts to move from the lens position 1 to the lens position 2.

  FIG. 3 also shows an operation timing when a position variation exceeding a predetermined deviation range occurs during holding control of the projection lens 37 at the lens position 2. As shown in P1 of FIG. 3A, when the projection lens 37 is located at the lens position 2 and exceeds a predetermined range due to disturbance during laser pulse output, the scanner control unit 25 detects this, and FIG. At the timing indicated by P2 in (b), the movement completion signal is switched from the “H” level to the “L” level and output, and the laser control unit 21 is notified of an abnormality that is out of the target position.

  When the movement completion signal becomes “L” level, the laser control unit 21 receives the abnormality notification and stops the laser output at the timing indicated by P3 in FIG.

  In the abnormality detection, when the position of the projection lens 37 exceeds the movement position determination threshold for a predetermined period (Tmask) or more, the movement completion signal is switched from the “H” level to the “L” level and output. This prevents erroneous detection due to noise in the position detection signal obtained from the position detectors 43a and 43b.

  The scanner control unit 25 detects a deviation of the projection lens 37 from the current target position, performs feedback control so as to match the target position, and once the position of the projection lens 37 is moved within the movement position determination threshold value again. The movement completion signal output is changed from the “L” level to the “H” level, and the laser diode 31 is allowed to project light again.

  FIG. 4 shows horizontal and vertical angle scanning timings and laser pulse emission timings.

  The upper graph in FIG. 4 shows the temporal change in the projection lens position in the horizontal direction, and the lower graph in the vertical direction.

  In response to the horizontal projection lens movement instruction, the movement from the predetermined start position to the target position and the holding stop control to the target position are controlled a predetermined number of times, and laser pulses are emitted to the target position during the holding control. After the movement and holding operation in the horizontal direction is performed up to a predetermined end position, the movement to the start position is performed, and the horizontal scanning is completed.

  The movement of the projection lens position in the vertical direction changes the position instruction of the projection lens 37 for each scanning in the horizontal direction. The vertical movement is performed at the timing when moving from the horizontal scanning end position to the scanning start position. By performing the scanning in the horizontal direction and the vertical direction together, the projection range of the laser pulse becomes as shown in the irradiation range 65 of FIG. The scanning timing in the horizontal direction and the vertical direction may be changed according to the required detection accuracy in each projection direction.

  Next, a processing operation in which the laser radar of the present embodiment configured as described above scans the outgoing optical axis will be described with reference to the flowchart of FIG.

  In FIG. 5, the left side is an operation flow of the laser control unit 21, and the right side is an operation flow of the scanner control unit 25. The processes of the laser control unit 21 and the scanner control unit 25 are performed in parallel.

  First, in step S <b> 11, the scanner control unit 25 executes a subroutine “projection lens position tracking control”. In this process, an additional value control routine (steps S31 to S35 in the flowchart of FIG. 6), which will be described later, is always performed at regular intervals.

  In the additional value control routine, as shown in the flowchart of FIG. 6, first, in step S31, the current projection lens position is detected, and then in step S32, the amount of deviation from the target position is calculated. In step S33, it is determined whether or not the projection lens position is within a predetermined range. In step S34, the operation amount of the actuator 40 is calculated by the control calculation unit 48 from the calculation result of step S32. Next, in step S35, an instruction is given to the linear motor driver 50 from the result of step S34, and drive output is performed to the actuator 40. As a result, the position of the projection lens 37 is controlled to follow the position instruction value.

  As described above, the subroutine “follow-up control” is executed when the interval interrupt is started in step S1 in the flowchart of FIG. 5, and returns to the original routine when the interval interrupt is released.

  Next, in step S1, a movement angle instruction to be the target projection direction is set, and in step S2, a movement start command (Sig. 1) is transmitted from the laser control unit 21 to the scanner control unit 25. In the scanner control unit 25, when a command from the laser control unit 21 is received in step S12, in a subsequent step S13, the movement target position instruction is calculated and set from the movement angle instruction in the lens position instruction calculation unit 45. The

  In step S14, a movement amount with respect to the current designated position of the projection lens 37 is calculated from the movement target position instruction, and a movement profile of the movement position instruction value is calculated according to the movement amount. Next, in step S15, the scanner control unit 25 outputs a position indication value for each fixed time period in accordance with the movement profile calculation result. Then, when the position instruction value coincides with the movement target position in step S16, the process proceeds to step S17 and the position instruction value is fixed to the movement target position.

  In parallel with the processing of steps S15, S16, and S17, the tracking control routine described above (steps S31 to S35 in the flowchart of FIG. 6) is always performed at regular intervals. The position of the projection lens 37 is moved following.

  In step S17, the projection lens 37 is moved to the target position based on the result processed in step S33 (of the flowchart of FIG. 6), and in the subsequent step S18, the position detected by the position sensor calculation unit 51 and the movement are moved. The target position is compared. Then, when the deviation between the two is within the predetermined range, the process proceeds to step S19, and the laser control unit 21 is notified of the movement completion signal (Sig. 2).

  In the scanner controller 25, after the movement completion notification in step S19, the process proceeds to step S20, and the position of the projection lens 37 is controlled to be held at the target position. While this holding control is being performed, the processing result of step S33 described above is confirmed at regular intervals. As a result, in step S21, when the lens displacement amount is within the predetermined range, the process proceeds to step S22, and the movement completion notification (Sig. 4) is constantly output from the scanner control unit 25 to the laser control unit 21. Is done.

  On the other hand, if it is detected from the processing result of step S33 that the lens position deviation amount exceeds the predetermined range in step S21, the process proceeds to step S23, and the scanner control unit 25 moves to the laser control unit 21. The lens position deviation instruction (Sig. 5) is notified.

  In step S6, the laser control unit 21 proceeds to step S7 and stops laser emission when the lens position deviation instruction (Sig. 5) is received. Thereafter, the process proceeds to step S3 and waits until a movement completion notification (Sig. 4) is received from the scanner control unit 25 again. On the other hand, in the scanner control unit 25, the processing operations in steps S20 to S24 described above are repeatedly performed until the next movement command is received from the laser control unit 21 in step S24. And if the next movement command is received, it will transfer to said step S12 and subsequent processing operation will be repeated.

  During the processing, the laser control unit 21 is in a state of waiting for the movement completion signal (Sig. 2). After the movement completion signal is received in step S3, light emission is performed on the laser diode 31 in step S4, and the projection light 61 is irradiated. When the projection light 61 is irradiated onto the target object 62, the reflected light 63 enters the light receiving lens 55 of the light receiving unit 27. In step S <b> 5, the light incident on the light receiving lens 55 is detected by the light receiving sensor 56 as an electric signal corresponding to the light intensity.

  Thereafter, in step S6, the reception state of a movement completion notification (Sig. 3) or a lens position deviation notification (Sig. 5) described later from the scanner control unit 25 is determined. In a state where the lens position deviation amount is within a predetermined range, a movement completion notification (Sig4) is constantly output from the scanner control unit 25 to the laser control unit 21, and the process proceeds to step S8 to emit and receive light from the laser diode 31 described above. It is determined whether or not the processing operation has been performed a predetermined number of times. Then, the processes in steps S4 to S8 are repeated until the predetermined number of times is reached.

  If the processing operation has been performed a predetermined number of times in step S8, the process proceeds to step S9, and the reflected light reception timing from the laser emission start timing is determined based on the electrical signal detected in step S5. Is detected, and the distance from the target object 62 is calculated from the time difference result.

  In the laser control unit 21, after the processing operation up to step S9 described above is completed, the process proceeds to step S1, the subsequent processing operation is performed, and the scanner control unit 25 is instructed for the next projection angle position. . By moving the projection lens 37 in the horizontal and vertical directions and repeating the same operation, the beam angle is scanned in the horizontal and vertical directions.

  As described above, the projection lens 37 is repeatedly moved and stopped a predetermined number of times, then moved to the initial position of the beam scanning angle, and scanning is performed again.

  In the above-described embodiment, the time change, the movement amount, and the trajectory of the target lens position instruction at the time of the movement instruction are constant in each scan, but sequentially, according to the projection range at the time of movement, The time change, the movement amount, and the trajectory of the movement instruction may be changed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

It is a block block diagram which shows the whole structure of the laser radar to which the light projector of this invention was applied. It is a figure explaining the relationship between the moving direction of the projection lens 37, and the direction of the projection light 61. FIG. It is a timing chart for demonstrating the projection lens movement control operation | movement of a laser radar and light source light emission control timing in one Embodiment of this invention. 4 is a timing chart showing the movement timing of the projection lens in the horizontal direction and the vertical direction and the laser pulse emission timing. It is a flowchart for demonstrating the processing operation which the laser radar of one Embodiment of this invention scans an emitted optical axis. 6 is a flowchart for explaining the operation of a subroutine “follow-up control” in step S11 in the flowchart of FIG. 5. It is the block diagram which showed the structure of the optical radar apparatus of a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 21 ... Laser control part, 23 ... Laser light-emitting device, 24 ... Scanner part, 25 ... Scanner control part, 27 ... Light-receiving part, 30 ... Lens holder, 31 ... Laser diode, 32, 33 ... Relay lens, 35 ... Wire spring, 36 ... support member, 37 ... projection lens, 38a, 38b ... driven member, 39a, 39b ... slit, 40 ... actuator, 41a, 41b ... light source, 43a, 43b ... position detector (PSD), 45 ... lens position indication calculation unit , 46 ... Position deviation detection unit, 47 ... Determination unit, 48 ... Control calculation unit, 50 ... Linear motor driver, 51 ... Position sensor calculation unit, 53 ... Memory, 61 ... Projected light, 62 ... Target object, 63 ... Reflected light .

Claims (9)

A light projecting device that projects a light beam emitted from a first light source onto an object,
An optical element for setting a projection direction of a light beam emitted by the first light source;
An actuator for moving the optical element;
Position detecting means for detecting the position of the optical element;
Direction control means for designating the projection direction of the light beam and controlling the optical element to follow-up by the actuator;
Comprising
The direction control means controls the actuator to stop the optical element at a position corresponding to a plurality of predetermined directions while moving the optical element so that the light beam can scan a predetermined direction range. A light projection device characterized by   The light projecting device according to claim 1, wherein the direction control unit controls the actuator so that the light beam can move vertically and horizontally.   When the deviation from the projection direction is detected by the position detection means and is within a predetermined range, the light source is notified that the light emission operation is possible, and when the projection direction is out of the predetermined range, The light projection device according to claim 1, wherein the light emission is notified to the light source.   The said position detection means has a 2nd light source, a light reception position detection element, and a slit interlock | cooperated with the said optical element, The detection output of the said optical element position is obtained, The said output means is characterized by the above-mentioned. Floodlight device. A first light source that emits a predetermined light beam;
A movable optical element for setting a projection direction of a light beam emitted from the first light source;
In order to scan a predetermined range by changing the projection direction of the light beam emitted from the first light source, the optical element is two-dimensionally oriented in a direction perpendicular to the optical axis direction of the first light source. An actuator to be moved,
Position detecting means for detecting the position of the optical element;
The projection direction of the light beam is designated, and the optical element is driven and controlled by the actuator. The optical element is moved so that the light beam can scan the predetermined range, and the optical element corresponds to a plurality of predetermined directions. Direction control means for controlling the actuator to stop the light beam at a position where
A light projection device comprising:   The light projecting device according to claim 5, wherein the direction control unit controls the actuator so that the light beam can move in a plane direction perpendicular to an optical axis direction of the first light source. .   The direction control means detects a deviation from the light projection direction by the position detection means, and notifies the first light source of light emission stop when the light projection direction is outside the predetermined range. The light projecting device according to claim 5, wherein   The direction control means detects a deviation from the light projection direction by the position detection means, and notifies the first light source that light emission is possible when the light projection direction is within the predetermined range. The light projection device according to claim 5.   The position detecting means includes a second light source different from the first light source, a light receiving position detecting element, a slit that moves in conjunction with the movement of the optical element, and light emitted from the second light source. And a light receiving position detecting element for detecting the position of the optical element by receiving light through the slit.

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