JP2017078315A - Interference prevention device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the existence of an obstacle's interference in an interference risk region, in a short time.SOLUTION: A prediction unit 121 predicts an obstacle's approach position to an operator cab 31 by using posture information measured by angle sensors 101 to 103. A limitation unit 122 limits a measurement range by selecting a measurement sensor capable of measuring a predicted approach position P1 from measurement sensors 111, 112, as an effective measurement sensor. An interference determination unit 123 determines a risk of interference of the obstacle depending on whether or not the depth of an object measured by an effective measurement sensor selected by the limitation unit 122 enters within a warning area D1 or automated operation area D2. When it is determined by the interference determination unit 123 that the obstacle enters the warning area D1, an interference prevention unit 124 rings a buzzer 130.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an interference prevention device for a construction machine, which includes a working device whose pose can be changed and a cab.

  In the construction machine, an attachment other than the attachment assumed by the manufacturer of the construction machine may be attached by the user. Moreover, in a construction machine such as a dismantling machine, a member such as a dismantled building may be gripped. In these cases, there is an increased possibility that attachments and dismantled building members will become obstacles and interfere with the driver's cab. Therefore, a sensor is attached to the main body of the construction machine to detect the distance between the cab and the obstacle, thereby preventing the obstacle from interfering with the cab.

  For example, in Patent Document 1, a distance of a work tool that approaches the boom hydraulic cylinder is detected using an ultrasonic sensor provided in the boom hydraulic cylinder, and the work tool is predetermined from the boom hydraulic cylinder based on the detection result. An interference prevention device is disclosed that determines whether or not the distance is within a distance range and sounds a buzzer when it is determined that the distance is within a predetermined distance range.

  However, since the ultrasonic sensor has a narrow measurement range, there is a problem that the distance of an obstacle cannot be accurately detected with only one ultrasonic sensor.

  Therefore, Patent Document 2 discloses an interference prevention device that uses a plurality of ultrasonic sensors to determine whether or not a bucket has entered a collision risk area set in front of the cab.

JP-A-2005-248502 JP 2001-64992 A

  However, if a plurality of ultrasonic sensors are simultaneously emitted, the ultrasonic sensors interfere with each other, and there is a problem that the distance of the obstacle cannot be detected accurately. Therefore, it is conceivable to measure the distance of an obstacle by emitting ultrasonic waves from a plurality of ultrasonic sensors in a time-sharing manner. However, since ultrasonic waves are not as fast as light, there is a problem that the measurement time per frame of a plurality of ultrasonic sensors becomes long.

  On the other hand, a distance sensor that measures the distance of an obstacle in pixel units using a stereo image or an infrared image is known. Therefore, it is conceivable to detect the presence or absence of obstacle interference using these distance sensors.

  However, since such a distance sensor requires image processing such as search processing for the closest point and filter processing for increasing the distance measurement accuracy, there is a problem that processing load is large and processing time is long.

  In addition, it is useless to constantly monitor the entire interference risk area using a distance sensor in order to determine the approach of an obstacle that exists only in a part of the interference risk area, reducing the processing time. There is room for further improvement.

  An object of the present invention is to provide an interference prevention device for a construction machine that can detect in a short time whether or not an obstacle interferes with an interference risk area.

An interference prevention device for a construction machine according to an aspect of the present invention is an interference prevention device for a construction machine including a working device capable of changing a posture and a cab.
A measurement unit attached to the front of the cab and measuring a distance from itself to an object located in front of the cab;
Using the distance measured by the measurement unit, an interference determination unit that determines the risk of interference with the driver's cab by an obstacle that is a gripped object of the work device or the work device;
When it is determined by the interference determination unit that there is a risk of the interference, an interference prevention unit that performs at least one of warning to a rider and operation restriction of the construction machine,
An acquisition unit for acquiring posture information indicating the posture of the working device;
A prediction unit that predicts an approach position from the cab to the obstacle using the posture information;
A limiting unit that limits a measurement range by the measurement unit according to a predicted approach position predicted by the prediction unit;
The interference determination unit determines the risk of the interference using the measured distance of the object in the measurement range limited by the limitation unit.

  If the posture of the working device is known, the position of the obstacle that is the gripping object of the working device or the working device can be predicted to some extent from the posture. In this configuration, the approach position from the cab to the obstacle is predicted using the attitude information indicating the attitude of the work device, and the measurement range by the measurement unit is limited according to the predicted predicted approach position. Therefore, useless measurement operations can be omitted, and the presence or absence of interference with an obstacle risk area can be detected in a short time. Furthermore, since the processing range is narrowed down to a limited measurement range, the detection accuracy can be increased and at the same time power consumption can be suppressed.

In the above aspect, the measurement unit includes a plurality of measurement sensors,
The limiting unit may limit the measurement range by selecting a measurement sensor capable of measuring the predicted approach position from the plurality of measurement sensors.

  When the measurement unit is configured with multiple measurement sensors to cover the entire interference risk area, if these measurement sensors simultaneously measure distances, the measurement waves may interfere with each other and the measurement accuracy may deteriorate. . In particular, when a plurality of measurement sensors are configured with measurement sensors that emit infrared rays and receive reflected light, interference between infrared rays becomes a problem. In this aspect, the measurement range is limited by selecting a measurement sensor capable of measuring the predicted approach position from a plurality of measurement sensors. Therefore, the most effective measurement sensor for detecting an obstacle can be selected, and measurement accuracy can be increased and power consumption can be reduced.

  In the above aspect, the limit unit includes a change unit that changes a measurement direction of the measurement unit, and limits the measurement range by directing the measurement direction of the measurement unit toward the predicted approach position using the change unit. May be.

  In this aspect, since the measurement range is limited by changing the measurement direction of the measurement unit toward the predicted approach position, an object near the predicted approach position is measured by the measurement unit without providing a plurality of measurement units. Can be made. Note that the change of the measurement direction of the measurement unit can be easily realized by using, for example, an actuator.

In the above aspect, the measurement unit includes a camera,
The limiting unit may limit the measurement range by extracting a region including the predicted approach position from data indicating an image acquired by the camera.

  In this aspect, since the measurement range is limited by extracting the region including the predicted approach position from the data indicating the image acquired by the camera, the processing target can be narrowed down and the processing time can be shortened.

  The said aspect WHEREIN: The said measurement part may be comprised with a distance sensor provided with the light source which irradiates infrared rays, and the camera which light-receives the reflected light of the said infrared rays.

  A distance sensor including a light source that emits infrared light and a camera that receives reflected light of infrared light has recently been put into practical use as an input interface for consumer games, and has high reliability. In this aspect, since such a distance sensor is employed, highly reliable distance measurement can be realized.

  The said aspect WHEREIN: The said measurement part may be comprised with a distance sensor provided with a stereo camera.

  In recent years, a distance sensor including a stereo camera has been put into practical use for in-vehicle applications and has high reliability. In this aspect, since such a distance sensor is employed, highly reliable distance measurement can be realized.

In the above aspect, the measurement unit includes a plurality of distance sensors installed in the operator's cab so that the entire area of the risk of interference set in the vicinity of the operator's cab can be measured.
The interference determination unit may determine the risk of the interference using distances measured by the plurality of distance sensors in the measurement range limited by the limitation unit.

  The front of the cab is a wide area, and if you consider the risk of interference to the upper surface of the cab, the entire area of the risk of interference can be reached by just providing one distance sensor with a narrow measurement range such as an ultrasonic sensor or millimeter wave sensor. I can't cover it. In this aspect, a plurality of distance sensors are installed in the driver's cab so that the entire area of the risk region of interference set in the vicinity of the driver's cab can be measured. Therefore, the plurality of distance sensors can measure the entire area of the risk of interference without blind spots. Moreover, in this aspect, in the measurement range limited by the limiting unit, the risk of interference is determined using the distances measured by the plurality of distance sensors. Therefore, useless measurement operations can be omitted, and the presence or absence of interference with an obstacle risk area can be detected in a short time. Furthermore, since the processing range is narrowed down to a limited measurement range, the detection accuracy can be increased and at the same time power consumption can be suppressed.

In the above aspect, the limiting unit limits the measurement range by selecting one or more distance sensors capable of measuring the predicted approach position from the plurality of distance sensors.
The interference determination unit may determine the risk of interference using a distance measured by the selected one or more distance sensors.

  In this aspect, the measurement range is limited by selecting a measurement sensor capable of measuring the predicted approach position from a plurality of measurement sensors. Therefore, the most effective measurement sensor for detecting an obstacle can be selected, and measurement accuracy can be increased and power consumption can be reduced.

  In the above aspect, the limiting unit controls the measurement by controlling the phase of the measurement wave radiated from each of the plurality of distance sensors so that the overall directivity of the plurality of distance sensors faces the predicted approach position. The range may be limited.

  In this aspect, the overall directivity of the plurality of distance sensors can be set in an arbitrary direction by controlling the phase of the measurement wave radiated from each of the plurality of distance sensors. Therefore, it is possible to measure the entire interference risk area with a small number of distance sensors. In addition, by controlling the phase of the measurement wave radiated from each of the multiple distance sensors so as to face the predicted approach position, it is possible to pinpoint the presence or absence of obstacle interference to the interference risk area, and the processing speed is high. Can be achieved.

  In the above aspect, the plurality of distance sensors may be arranged in a two-dimensional array.

  In this aspect, since the plurality of distance sensors are arranged in a two-dimensional array, it becomes possible to direct the overall directivity of the plurality of distance sensors in an arbitrary direction combining the vertical direction and the horizontal direction, The entire area of the two-dimensional interference danger area set on the front or upper part of the cab can be covered.

  In the above aspect, the interference determination unit may determine the risk of interference using a minimum distance among the distances measured by the plurality of distance sensors in the measurement range limited by the limitation unit.

  According to this configuration, since the risk of interference is determined using the minimum distance among the distances measured by the plurality of distance sensors in the measurement range limited by the limiting unit, the closest approach position of the obstacle is It is possible to accurately determine whether or not an intrusion danger area has been entered.

  In the above aspect, the plurality of distance sensors may be constituted by ultrasonic sensors arranged on a lattice-like member installed on at least one of the front surface and the upper surface of the cab.

  In general, in an ultrasonic sensor, ultrasonic waves spread concentrically around a radiation direction, so that ultrasonic waves interfere with each other when the ultrasonic sensors are brought close to each other. Therefore, in order to cover the entire area of the risk of interference, it is necessary to arrange the ultrasonic sensors while ensuring a certain distance or more. In this aspect, since the plurality of ultrasonic sensors are arranged on a lattice-like member arranged on at least one of the front surface and the upper surface of the cab, the ultrasonic sensors can be arranged with a certain level or more secured.

  The lattice member may be at least one of a front guard and a head guard.

  Construction machinery such as steel cutting machines, concrete crushers, and demolition grippers are equipped with a front guard for protecting the front of the cab and a head guard for protecting the top of the driver's seat as protective equipment for ensuring safety. Yes. By using these members to arrange the ultrasonic sensors in a grid pattern on the front guard and head guard, it is not necessary to provide a dedicated member for attaching the ultrasonic sensors, and the operator's field of view exceeds that of the protective equipment. No longer gets worse.

In the above aspect, the work device includes a boom that is swingably attached to the cab, an arm that is swingably attached to the boom, and a swingably attached to the arm. With attached attachments,
The acquisition unit may acquire at least one of rotation angles of the boom, the arm, and the attachment as the posture information.

  If at least one of the rotation angles of the boom, arm, and attachment is known, the position of the obstacle can be predicted to some extent. In this aspect, since these rotation angles are acquired as posture information, the predicted approach position can be predicted with a certain degree of accuracy.

  In the above aspect, the prediction unit may predict the distance between the tip of the arm or the tip of the attachment and the cab as the approach position.

  If the position of the tip of the arm or the tip of the attachment is known, the position of the obstacle closest to the cab (closest approach position) can be predicted to some extent. In this aspect, since the distance between the tip of the arm or the tip of the attachment and the cab is predicted as the approach position, the closest approach position is reduced while reducing the processing load compared to the case where the closest approach position is strictly predicted. Can be detected with a certain degree of accuracy.

  In the present invention, the approach position of the obstacle to the cab is predicted using the attitude information indicating the attitude of the work device, and the measurement range by the measurement unit is limited according to the predicted predicted approach position. Therefore, useless measurement operations can be omitted, and the presence or absence of interference with an obstacle risk area can be detected in a short time. Furthermore, since the processing range is narrowed down to a limited measurement range, the detection accuracy can be increased and at the same time power consumption can be suppressed.

1 is an external view of a construction machine to which an interference preventing apparatus according to Embodiment 1 is applied. 1 is a block diagram illustrating an example of a system configuration of a construction machine according to Embodiment 1. FIG. It is explanatory drawing of the process in which a estimation part calculates a prediction approach position. 3 is a flowchart showing the operation of the construction machine in the first embodiment. FIG. 6 is an external view of a construction machine in a second embodiment. 6 is a block diagram illustrating an example of a system configuration of a construction machine according to Embodiment 2. FIG. 6 is a flowchart showing a process of the construction machine in the second embodiment. In Embodiment 3, it is a figure which shows an example of the distance image data which the effective distance sensor acquired. 10 is a flowchart showing a process of the construction machine in the third embodiment. FIG. 10 is an external view of a construction machine in a fourth embodiment. It is a figure of the upper view of the construction machine in Embodiment 4. FIG. FIG. 10 is a block diagram showing a system configuration of a construction machine in a fourth embodiment. 10 is a flowchart showing processing of the construction machine according to the fourth embodiment. FIG. 10 is an external view of a construction machine in a fifth embodiment. FIG. 10 is a block diagram showing a system configuration of a construction machine in a fifth embodiment. FIG. 10 is a diagram for explaining control of an ultrasonic sensor in a fifth embodiment. 10 is a flowchart showing the operation of the construction machine in the fifth embodiment. FIG. 10 is a diagram showing an arrangement of ultrasonic sensor arrays in a first modification of the fifth embodiment. FIG. 10 is an external view of a construction machine in a first modification of the fifth embodiment. FIG. 10 is a top view of a construction machine in a second modification of the fifth embodiment. FIG. 20 is an external view of a construction machine in a sixth embodiment. It is a figure which shows the directivity of an ultrasonic sensor. It is the figure which showed the example of arrangement | positioning of an upper surface lattice member and a front surface lattice member. It is the figure which showed the arrangement | positioning pattern 1 of an ultrasonic sensor. It is the figure which showed the arrangement | positioning pattern 2 of an ultrasonic sensor. It is the figure which showed the arrangement | positioning pattern 3 of an ultrasonic sensor. In Embodiment 6, it is the figure which showed a mode that the ultrasonic sensor attached to the construction machine was radiating | emitting an ultrasonic wave. It is a figure which shows a mode that the construction machine in Embodiment 6 has limited the measurement range.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The following embodiments are examples embodying the present invention, and are not of a nature that limits the technical scope of the present invention.

(Embodiment 1)
FIG. 1 is an external view of a construction machine 1 to which the interference prevention apparatus according to Embodiment 1 is applied. Here, a hybrid excavator is taken as an example of the construction machine 1, but the interference prevention device may be applied to other construction machines such as an excavator car and a crane. Hereinafter, the front side direction of the cab 31 is described as front, the rear side direction of the cab 31 is described as rear, the upper side of the cab 31 is described as upper, and the lower direction of the cab 31 Is described as downward. In addition, the front and rear are collectively referred to as the front-rear direction, and the upper and lower directions are collectively referred to as the vertical direction. Further, when looking forward from the cab 31, the left direction is described as left, and the right direction is described as right. Further, the left side and the right side are collectively referred to as the left-right direction.

  The construction machine 1 includes a crawler type lower traveling body 2, an upper revolving body 3 that is turnably provided on the lower traveling body 2, and a work device 4 that is attached to the upper revolving body 3 and can change its posture. I have.

  The work device 4 includes a boom 15 attached to the upper swing body 3 so as to be able to move up and down, an arm 16 attached so as to be swingable with respect to the distal end portion of the boom 15, and swinging with respect to the distal end portion of the arm 16. And an attachment 17 movably attached thereto.

  The upper swing body 3 is formed of a box and includes a cab 31 in which an operator gets on. In the cab 31, the front surface is described as a front surface 31 a and the upper surface is described as an upper surface 31 c. In the example of FIG. 1, an inclined surface 31 b that gradually increases in height toward the rear is provided between the front surface 31 a and the upper surface 31 c.

  A warning area D1 and an automatic operation area D2 are set in front of the cab 31 in order from the front side. The warning area D1 is an area for notifying the operator that the obstacle is approaching the cab 31 and the danger is imminent or restricting the operation of the work device 4 when an obstacle enters. It is. The automatic operation area D2 is an area for automatically stopping or restricting the operation of the work device 4 when an obstacle enters. The warning area D1 corresponds to an example of an interference danger area.

  The warning area D1 is partitioned by the boundary surface L1 and the boundary surface L2. The boundary surface L1 includes a boundary surface L11 facing the front surface 31a and a boundary surface L12 facing the inclined surface 31b. The boundary surface L11 is a plane set parallel to the front surface 31a at a position d11 away from the front surface 31a. The boundary surface L12 is a plane that is set on the upper side from the upper end K1 of the boundary surface L11 and is set apart from the inclined surface 31b by a distance d11.

  The automatic operation region D2 is partitioned by the boundary surface L2, the front surface 31a, and the inclined surface 31b. The boundary surface L2 includes a boundary surface L21 facing the front surface 31a and a boundary surface L22 facing the inclined surface 31b. The boundary surface L21 is a plane set in parallel with the front surface 31a at a position d12 (<d11) away from the front surface 31a. The boundary surface L22 is a plane that is set on the upper side from the upper end K2 of the boundary surface L21 and is set apart from the inclined surface 31b by a distance d12. The height of the upper end K1 is set at a position higher than the upper end K2.

  Note that the uppermost ends of the warning area D1 and the automatic operation area D2 are provided in the vicinity of the upper end C111_a of the measurement range C111 of the measurement sensor 111, for example. Further, the lowermost ends of the warning area D1 and the automatic operation area D2 are provided, for example, in front of the lower part of the cab 31. Further, the width in the left-right direction of the warning area D1 and the automatic operation area D2 is set to, for example, the width in the left-right direction of the front surface 31a or a width provided with a slight margin. However, these are examples, and the uppermost end, the lowermost end, and the width in the left-right direction of the warning area D1 and the automatic operation area D2 may not be defined. The uppermost ends of the warning area D1 and the automatic operation area D2 may be extended to the rear end of the upper surface 31c of the cab 31. Hereinafter, the three-dimensional coordinate system in which the warning area D1 and the automatic operation area D2 are set is described as the coordinate system of the construction machine 1.

  On the front surface 31a, a measurement sensor 111 is provided at the upper end, and a measurement sensor 112 is provided at the lower end. The measurement sensors 111 and 112 have fan-shaped measurement ranges C111 and C112, respectively, when viewed in the left-right direction. The measurement sensors 111 and 112 are spaced apart in the vertical direction on the front surface 31a so that the measurement ranges C111 and C112 can cover at least the entire boundary surface L2. Thereby, the blind spot of the measurement sensors 111 and 112 does not occur in the warning area D1, and the construction machine 1 can issue a warning to the operator before the obstacle enters the automatic operation area D2.

  The construction machine 1 further includes angle sensors 101, 102, and 103. The angle sensor 101 is provided at the rotation fulcrum of the boom 15 and measures the rotation angle of the boom 15. The angle sensor 102 is provided at the rotation fulcrum of the arm 16 and measures the rotation angle of the arm 16. The angle sensor 103 is provided at the rotation fulcrum of the attachment 17 and measures the rotation angle of the attachment 17.

  FIG. 2 is a block diagram illustrating an example of a system configuration of the construction machine 1 according to the first embodiment. The construction machine 1 includes an engine 210, a hydraulic pump 250 and a generator motor 220 connected to the output shaft of the engine 210, and a control valve 260 that controls supply and discharge of hydraulic oil from the hydraulic pump 250 to the hydraulic cylinders 281, 282, and 283. An electric storage device 240 that can charge the electric power generated by the generator motor 220, an inverter 230 that converts electric power between the electric storage device 240 and the generator motor 220, and an operation by an operator for changing the attitude of the work device 4 And an operation lever 270 for receiving the.

  The hydraulic pump 250 is operated by the power of the engine 210 and discharges hydraulic oil. The hydraulic oil discharged from the hydraulic pump 250 is guided to the hydraulic cylinders 281, 282, and 283 while the flow rate is controlled by the control valve 260.

  The operation lever 270 outputs a signal indicating the operation amount to the controller 270. The control valve 260 sets the opening of the valve to an opening corresponding to the operation amount of the operation lever 270 under the control of the controller 270.

  The hydraulic cylinder 281 expands and contracts with the supply of hydraulic oil, thereby raising and lowering the boom 15 with respect to the upper swing body 3. The hydraulic cylinder 282 swings the arm 16 with respect to the boom 15 by expanding and contracting with the supply of hydraulic oil. The hydraulic cylinder 283 causes the attachment 17 to swing with respect to the arm 16 by expanding and contracting upon receiving the supply of hydraulic oil.

  The generator motor 220 has a configuration as a generator that converts the power of the engine 210 into electric power, and a configuration as an electric motor that converts the electric power stored in the power storage device 240 into power. In the example of FIG. 2, the generator motor 220 is configured by, for example, a three-phase motor, but this is an example and may be configured by a single-phase motor.

  The power storage device 240 is composed of various secondary batteries such as a lithium ion battery, a nickel metal hydride battery, an electric double layer capacitor, and a lead battery.

  The inverter 230 controls switching between the operation of the generator motor 220 as a generator and the operation of the generator motor 220 as an electric motor under the control of the controller 120. The inverter 230 controls the current to the generator motor 220 and the torque of the generator motor 220 under the control of the controller 120. In the example of FIG. 2, the inverter 230 is configured by, for example, a three-phase inverter. However, this is an example, and the inverter 230 may be configured by a single-phase inverter.

  Furthermore, the construction machine 1 includes an acquisition unit 100, a measurement unit 110, and a controller 120.

  The acquisition unit 100 includes the angle sensors 101, 102, 102 described with reference to FIG. 1 and acquires posture information indicating the posture of the work device 4. Here, the rotation angle of the boom 15, the rotation angle of the arm 16, and the rotation angle of the attachment 17 correspond to the posture information.

  The measurement unit 110 includes the measurement sensors 111 and 112 described in FIG. 1, and measures the distance from itself to an object located around the cab 31. In the present embodiment, the measurement sensors 111 and 112 are depth sensors including, for example, a light source that emits infrared light, a camera that can receive infrared light and visible light, and a processor that processes image data captured by the camera. It is configured.

  For example, the measurement sensors 111 and 112 irradiate infrared rays at regular intervals (for example, 30 fps), and measure the time from irradiation of infrared rays to reception of reflected light in units of pixels, from the sensor surface to the object. Measure the distance distribution.

  In recent years, depth sensors that irradiate infrared rays have been increasingly put into practical use as distance measuring means, and are used as an input interface for performing gesture input in games and the like. In addition, since the construction machine 1 may be used at night, a depth sensor using infrared rays is useful for the construction machine 1. In the depth sensor that irradiates infrared rays, the method of measuring the time from when the infrared rays are irradiated until the reflected light is received is known as the ToF (Time of flight) method. In addition, as the depth sensor, a pattern irradiation method for measuring a distance from a light receiving pattern of reflected light when a specific pattern is irradiated is known, and a depth sensor of this pattern irradiation method may be adopted. Since the construction machine 1 often works outdoors, a laser scanning ToF type depth sensor that is resistant to interference with sunlight may be employed.

  Here, although the depth sensor is used as the measurement sensors 111 and 112, the present invention is not limited to this, and may be configured with a stereo camera that is relatively inexpensive as compared to the depth sensor. In this case, the measurement sensors 111 and 112 include, for example, a stereo camera and a processor that calculates a distribution of distances from a plurality of pieces of image data captured by each camera constituting the stereo camera to an object.

  In the present embodiment, the measurement sensors 111 and 112 are not limited to those described above, and any measurement sensor may be used as long as the measurement sensor can calculate the distance from the cab 31 to the object from the attachment position and angle. May be. For example, a measurement sensor described in Non-Patent Document 1 may be employed.

  The controller 120 includes a processor such as a microcontroller and a storage device that stores programs and the like. The controller 120 includes a prediction unit 121, a limiting unit 122, an interference determination unit 123, and an interference prevention unit 124. The prediction unit 121 to the interference prevention unit 124 may be configured by a dedicated hardware circuit, or may be realized by the CPU executing a program.

  The prediction unit 121 predicts the approach position from the cab 31 to the obstacle using the posture information measured by the angle sensors 101 to 103. Hereinafter, the approach position predicted by the prediction unit 121 is described as a predicted approach position. The obstacle corresponds to the work device 4 or the gripping object of the work device 4, but in the following description, the tip of the arm 16 or the tip of the attachment 17 is assumed to be applicable. Note that when the gripping object of the work device 4 is an obstacle, the prediction unit 121 may adopt a position that is separated from the tip of the arm by a predetermined offset distance in the backward direction as the predicted approach position. As the offset distance, a predetermined value in consideration of the assumed size of the grasped object may be adopted.

  When the attachment 17 has been changed by the user, or when the attachment 17 is holding a gripped object, the calculated predicted approach position does not necessarily interfere with the cab 31. Therefore, in the present embodiment, the predicted approach position is utilized as reference information for estimating the approximate position of the obstacle. In other words, the predicted approach position is used to validate the measurement sensor around the calculated predicted approach position and to determine that the measurement sensor away from the calculated predicted approach position is invalid.

  FIG. 3 is an explanatory diagram of a process in which the prediction unit 121 calculates a predicted approach position. In FIG. 3, the boom 15, the arm 16, and the attachment 17 are shown as straight lines to simplify the description. The lengths of the boom 15, the arm 16, and the attachment 17 are known. The distance dα in the front-rear direction between the front surface 31a of the cab 31 and the angle sensor 101 is also known. Therefore, if the rotation angle θ1 of the boom 15 with respect to the front surface 31a, the rotation angle θ2 of the arm 16 with respect to the boom 15, and the rotation angle θ3 of the attachment 17 with respect to the arm 16 are known, a trigonometric function is used to calculate the altitude dy of the predicted approach position P1. And the depth dz can be calculated. Here, the altitude dy refers to the vertical distance from the reference plane SE parallel to the front-rear direction to the predicted approach position P1, for example, and the depth dz refers to the front-rear direction from the front surface 31a to the predicted approach position P1, for example. Refers to the distance. In the example of FIG. 3, the reference plane SE is set so as to pass through the angle sensor 101, but this is an example. In the example of FIG. 3, in the coordinate system of the construction machine 1, the front surface 31 a is set as the origin in the front-rear direction, the reference plane SE is set as the origin in the up-down direction, and the center in the left-right direction of the front surface 31 a is the left-right direction. Set to limited.

  In addition, when the attachment 17 takes the attitude | position shown by the dotted line of FIG. 3, the front-end | tip P1 'of the arm 16 becomes closer to the front surface 31a rather than the front-end | tip P2 of the attachment 17. FIG. In this case, the prediction unit 121 may calculate the tip P1 'of the arm 16 instead of the tip of the attachment 17 as the predicted approach position P1.

  Here, if the posture of the attachment 17 is directed forward with respect to the vertical direction, the tip end P <b> 1 ′ of the arm 16 is closer to the front surface 31 a than the tip end P <b> 2 of the attachment 17. Therefore, the predicting unit 122 determines whether or not the posture of the attachment 17 is directed forward with respect to the vertical direction based on the magnitudes of the rotation angles θ1 to θ3, and if it is directed forward, the tip P1 of the arm 16 is determined. 'May be calculated as the predicted approach position P1, and the tip of the attachment 17 may be calculated as the predicted approach position P1 if it faces backward.

  Alternatively, since the predicted approach position P1 is used to limit the measurement range, it is not necessary to be predicted precisely, and it is only necessary to be able to specify an approximate position. Therefore, the prediction unit 121 may calculate the tip P1 'of the arm 16 as the predicted approach position P1. In this case, the prediction unit 121 can calculate the predicted approach position P1 without using the rotation angle θ3. Alternatively, the prediction unit 121 may calculate the tip of the boom 15 as the predicted approach position P1. In this case, the prediction unit 121 can calculate the predicted approach position P1 without using the rotation angles θ3 and θ2.

  Returning to FIG. The limiting unit 122 limits the measurement range by the measuring unit 110 according to the predicted approach position P1 predicted by the prediction unit 121.

  In the present embodiment, the limiting unit 122 limits the measurement range by selecting a measurement sensor capable of measuring the predicted approach position P1 from the measurement sensors 111 and 112 as an effective measurement sensor. For example, referring to FIG. 1, the limiting unit 122 calculates the distance between the predicted approach position P1 and the center line C111_b of the measurement range C111 and determines the distance between the predicted approach position P1 and the center line C112_b of the measurement range C112. A measurement sensor that calculates and uses a center line with a shorter distance as a measurement range may be selected as an effective measurement sensor. As a result, the most effective measurement sensor for detecting an obstacle can be selected, and the processing time can be shortened, the measurement accuracy can be increased, and the power consumption can be reduced.

  The interference determination unit 123 determines the risk of interference with the cab 31 due to an obstacle using the distance of the object measured by the measurement unit 110. Here, the interference determination unit 123 determines the risk of interference due to an obstacle based on whether or not the depth of the object measured by the effective measurement sensor has entered the warning area D1 or the automatic operation area D2.

  Specifically, the interference determination unit 123 detects the minimum depth of the depths indicated by the measurement data measured by the effective measurement sensor as the depth of the obstacle. In this case, the interference determination unit 123 may store in advance a distance d11 from the front surface 31a to the boundary surface L1 and a distance d12 from the front surface 31a to the boundary surface L2. Then, the interference determination unit 123 converts the minimum depth measured by the effective measurement sensor from the coordinate system of the effective measurement sensor to the coordinate system of the construction machine 1, and the converted depth is changed to the warning area D1 or the automatic operation area D2. What is necessary is just to determine whether it has penetrate | invaded.

  Alternatively, the interference determination unit 123 may determine the risk of interference in consideration of the height of the detected object in addition to the depth. In this case, in addition to the distances d11 and d12, the interference determination unit 123 further heights the uppermost end, the upper end K1, and the lowermost end of the boundary surface L1, and the heights of the uppermost end, the upper end K1, and the lowermost end of the boundary surface L2. Sato may be stored in advance. And the interference determination part 123 converts the coordinate which shows the minimum depth among the depths which the effective measurement sensor measured into the coordinate system of the construction machine 1 from the coordinate system of an effective measurement sensor, and the converted coordinate is warning area | region D1 or What is necessary is just to determine whether it has penetrate | invaded into the automatic driving | operation area | region D2.

  When the interference determination unit 123 determines that there is a risk of interference, the interference prevention unit 124 warns the operator and / or restricts the operation of the work device 4. Specifically, when the interference determination unit 123 determines that the obstacle is located in the warning area D1, the interference prevention unit 124 sounds the buzzer 130.

  When the interference determination unit 123 determines that the obstacle is located in the automatic driving area D2, the interference prevention unit 124 limits the operation of the work device 4 by decelerating or automatically stopping the work device 4. .

  In this case, the interference preventing unit 124 decelerates the work device 4 by correcting the opening degree of the control valve 260 set in accordance with the operation amount of the operation lever 270 in the direction to decelerate the work device 4. You can do it. Further, in this case, the interference prevention unit 124 may increase the deceleration amount of the work device 4 as the depth of the obstacle approaches the cab 31.

  The buzzer 130 is provided, for example, in the cab 31 and rings under the control of the interference prevention unit 124.

  In FIG. 2, the control valve 260 transmits the operation amount of the operation lever 270 via the controller 120, but the present invention is not limited to this. For example, a mode in which a solenoid valve is provided between the operation lever 270 and the control valve 260, the pressure output from the control lever 270 is reduced by the solenoid valve, and the opening degree of the control valve 260 is controlled by the reduced pressure is adopted. May be.

  FIG. 4 is a flowchart showing the operation of the construction machine 1 in the first embodiment. First, when the operation lever 270 is operated by the operator (YES in S401), the prediction unit 121 calculates the predicted approach position P1 using the rotation angles θ1 to θ2 measured by the angle sensors 101 to 103 (S402). On the other hand, if the operation lever 270 is not operated (NO in S401), the process returns to S401.

  Next, the limiting unit 122 selects an effective measurement sensor based on the predicted approach position P1 (S403). Next, the limiting unit 122 measures the depth of the object indicated by the measurement data measured by the effective measurement sensor (S404).

  Next, when the interference determination unit 123 determines that the measured depth of the object has entered the warning region D1 (YES in S405), the interference prevention unit 124 determines that an obstacle has entered the warning region D1, and the buzzer A warning is issued by ringing 130 (S406). On the other hand, when the interference determination unit 123 determines that the measured depth of the object has not entered the warning area D1 (NO in S405), the interference determination unit 123 determines that an obstacle has not entered the warning area D1, and the process proceeds to S401. return.

  Next, when the interference determination unit 123 determines that the measured depth of the object has entered the automatic driving region D2 (YES in S407), the interference prevention unit 124 indicates that the obstacle has entered the automatic driving region D2. It determines and restrict | limits operation | movement of the working apparatus 4 (S408). When S408 ends, the process returns to S401. On the other hand, when the interference determination unit 123 determines that the measured depth of the object has not entered the automatic driving area D2 (NO in S407), the interference determining unit 123 determines that the obstacle has not entered the automatic driving area D2, and performs processing. Return to S401.

  In the flowchart, when it is determined that an obstacle has entered the warning area D1, only the warning is performed, but the work device 4 may be decelerated. And when it determines with the obstruction having penetrate | invaded into the automatic driving | operation area | region D2, the interference prevention part 124 may make the work apparatus 4 stop automatically. Alternatively, when it is determined that an obstacle has entered the warning area D1, the interference prevention unit 124 operates the work device 4 so that the obstacle does not enter the automatic operation area D2, regardless of the amount of operation of the operation lever 270. May be restricted.

  As described above, in the first embodiment, the approach position of the obstacle to the cab 31 is predicted using the posture information indicating the posture of the work device 4, and the measurement by the measurement unit 110 is performed according to the predicted predicted approach position P1. The range is limited. Therefore, useless measurement operation can be omitted, and the presence or absence of interference with the warning area D1 of the obstacle can be detected in a short time. Furthermore, since the processing range is narrowed down to a limited measurement range, the detection accuracy can be increased and at the same time power consumption can be suppressed.

  In FIG. 1, a plurality of measurement sensors are provided, but the number of measurement sensors may be one as long as the warning area D1 and the automatic operation area D2 can be covered.

(Embodiment 2)
The construction machine 1 according to the second embodiment is characterized in that the measurement range of the measurement sensor is directed to the predicted approach position P1. FIG. 5 is an external view of the construction machine 1 according to the second embodiment. In the second embodiment, there is one measurement sensor 111. An actuator 110 a is attached to the measurement sensor 111. The actuator 110a rotates the measurement sensor 111 in the direction in which the elevation angle between the measurement sensor 111 and the front surface 31a is changed (the direction indicated by the arrow YA), and positions the measurement range C111 of the measurement sensor 111 at the predicted approach position P1. As a result, the range that can be measured by one measurement sensor 111 is remarkably increased, and it is not necessary to add a useless measurement sensor to cover the entire warning area D1.

  FIG. 6 is a block diagram illustrating an example of a system configuration of the construction machine 1 according to the second embodiment. 6 is different from FIG. 2 in that the measurement sensor 112 is omitted from the measurement unit 110 and an actuator 110a is provided. The rest is the same as FIG.

  The limiting unit 122 rotates the measurement sensor 111 so that the predicted approach position P1 calculated by the prediction unit 121 is included in the measurement range C111 of the measurement sensor 111. Referring to FIG. 5, for example, if the predicted approach position P1 is calculated at the illustrated position, the limiting unit 122 controls the actuator 110a so that the center line C111_b crosses the predicted approach position P1. Rotate 111.

  FIG. 7 is a flowchart showing processing of the construction machine 1 in the second embodiment. In this flowchart, the same reference numerals are assigned to the same processes as those in the flowchart of FIG.

  In S701 following S402, the limiting unit 122 controls the actuator 110a to change the direction of the measurement range C111 of the measurement sensor 111 so as to go to the predicted approach position P1 (S701).

  Next, the measurement sensor 111 measures the depth of the object in the changed measurement range C111 (S702). Thereafter, the same processing as in FIG. 4 is repeated.

  Thus, in the construction machine 1 according to the second embodiment, since the measurement range C111 of the measurement sensor 111 is changed toward the predicted approach position P1, the vicinity of the predicted approach position P1 without providing a plurality of measurement sensors. The object can be measured by the measurement sensor 111.

  In FIG. 5, the number of the measurement sensors 111 is one. However, when the warning area D1 is large and one measurement sensor 111 cannot cover the entire area of the warning area D1, a plurality of measurement sensors may be provided. In this case, an actuator 110a may be provided for each measurement sensor so that the measurement range of each measurement sensor can be changed individually.

(Embodiment 3)
The construction machine 1 according to the third embodiment extracts a part of the area including the predicted approach position P1 from the distance image data acquired as the measurement data by the effective measurement sensor in the first embodiment, and the object in the extracted area It is characterized by detecting the depth.

  FIG. 8 is a diagram illustrating an example of the distance image data G1 acquired by the effective measurement sensor in the third embodiment. The distance image data G1 includes images of the arm 16 and the attachment 17 as viewed from the front surface 31a side of the cab 31.

  Then, assuming that the predicted approach position P1 is located at the illustrated position, the limiting unit 122 sets a processing region D80 around the predicted approach position P1 in the distance image data G1, and sets the processing region D80 from the distance image data G1. Extract. In this case, the limiting unit 122 may plot the predicted approach position P1 in the distance image data G1 by converting the coordinate system of the predicted approach position P1 from the coordinate system of the construction machine 1 to the coordinate system of the effective measurement sensor.

  Here, as shown in FIG. 3, the predicted approach position P1 is data of two components of the depth dz and the altitude dy, so the position in the left-right direction is not known. Therefore, the limiting unit 122 may set the position in the left-right direction of the predicted approach position P1 to a position determined in advance from the relative positional relationship between the work device 4 and the cab 31. Alternatively, if the work device 4 is configured to be tiltable in the left-right direction, the rotation angle in the left-right direction of the work device 4 is measured by the angle sensor, and the prediction unit 121 determines the position in the left-right direction of the predicted approach position P1. It may be calculated.

  Note that the processing area D80 has a predetermined size in consideration of the type of the attachment 17 and a grasped object. In this case, the limiting unit 122 may change the size of the processing region D80 according to the type of the attachment 17. The limiting unit 122 may recognize the attachment 17 by causing the operator to input the type of the attachment 17.

  FIG. 9 is a flowchart showing processing of the construction machine 1 in the third embodiment. In this flowchart, the same reference numerals are assigned to the same processes as those in the flowchart of FIG.

  In S901 following S403, the limiting unit 122 extracts the processing region D80 from the distance image data measured by the effective measurement sensor. Next, the interference determination unit 123 detects the minimum depth in the processing region D80 as the depth of the obstacle (S902). Thereafter, the same processing as in FIG. 4 is repeated.

  Thus, in the construction machine 1 according to the third embodiment, the measurement range is limited by extracting the processing region D80 including the predicted approach position P1 from the distance image data G1 acquired by the measurement sensor. The processing time can be shortened.

  The third embodiment may be applied to the second embodiment. In this case, the processing region D80 is extracted from the distance image data G1 measured by the measurement sensor 111 positioned so that the measurement range C111 faces the predicted approach position P1.

(Embodiment 4)
The fourth embodiment is characterized in that a plurality of ultrasonic sensors are used so that at least the warning area D1 can be covered.

  FIG. 10 is an external view of the construction machine 1 according to the fourth embodiment. Three ultrasonic sensors 310 are arranged on the front surface 31a of the cab 31 in the vertical direction. FIG. 11 is a top view of the construction machine 1 according to the fourth embodiment. Three ultrasonic sensors 310 in the left-right direction are arranged on the front surface 31a of the cab 31.

  As described above, in the present embodiment, 3 rows × 3 columns = 9 ultrasonic sensors 310 are arranged in an array on the front surface 31 a of the cab 31.

  Here, the ultrasonic sensor 310 is adopted, but if the sensor can measure the distance to the object, a sensor that measures the distance to the object by irradiating a measurement wave such as millimeter wave, radio wave, or light is adopted. May be.

  The ultrasonic sensor 310 cannot measure the depth distribution like the depth sensor shown in the first embodiment, and can measure only the depth of the closest object in the measurement range E310. Therefore, even if the ultrasonic sensor 310 is an object that is approaching the front surface 31a, an object positioned obliquely forward increases the distance from the sensor surface, so that the depth is greatly measured. Therefore, the measurement range E310 of the ultrasonic sensor 310 cannot be set to a wide angle.

  The front surface 31a of the cab 31 is, for example, approximately 2m in length and approximately 1m in width and is wide. Therefore, one ultrasonic sensor 310 cannot cover the entire warning area D1. Therefore, in FIG. 10, a plurality of ultrasonic sensors 310 are provided.

  Specifically, as shown in FIGS. 10 and 11, the ultrasonic sensors 310 are arranged apart in the vertical direction and the horizontal direction so that the measurement range E310 can cover at least the entire area of the boundary surface L2. Thereby, the blind spot of the ultrasonic sensor 310 does not occur in the warning area D1, and the construction machine 1 can issue a warning to the operator before the obstacle enters the automatic operation area D2.

  FIG. 12 is a block diagram illustrating a system configuration of the construction machine 1 according to the fourth embodiment. 12 is different from FIG. 2 in that the measurement unit 110 is configured by a plurality of ultrasonic sensors 310 instead of the measurement sensors 111 and 112.

  For example, the ultrasonic sensor 310 emits an ultrasonic wave at regular time intervals (for example, every several tens of msec), measures the time from when the ultrasonic wave is emitted until it receives a reflected wave, and calculates the speed of sound × time / 2. By doing so, the distance to the object is measured.

  The limiting unit 122 limits the measurement range by selecting one or more ultrasonic sensors 310 capable of measuring the predicted approach position P1 from the ultrasonic sensors 310 as effective measurement sensors. For example, referring to FIG. 10, the limiting unit 122 selects one or more ultrasonic sensors 310 including the predicted approach position P <b> 1 in the measurement range E <b> 310 as an effective ultrasonic sensor in the left-right direction view (side view). Alternatively, the limiting unit 122 may obtain the distance between the predicted approach position P1 and each ultrasonic sensor 310, and may select the ultrasonic sensor 310 whose calculated distance is equal to or less than a threshold as an effective ultrasonic sensor. Here, as the threshold value, for example, a predetermined value expected that the measurement range E310 of the ultrasonic sensor 310 includes the predicted approach position P1 may be adopted.

  Referring to FIG. 11, limiting unit 122 sets one or more ultrasonic sensors 310 whose predicted approach position P1 is included in measurement range E310 as an effective ultrasonic sensor when viewed from above. Since the predicted approach position P1 is two-component data of the depth dz and the altitude dy, the limiting unit 122 predicts and approaches a predetermined position based on the relative positional relationship between the cab 31 and the work device 4. The position in the left-right direction of the position P1 may be set, or if the work device 4 rotates in the left-right direction, the position in the left-right direction of the predicted approach position P1 may be set from the rotation angle.

  Referring to FIG. 12, the interference determination unit 123 detects the minimum depth among the depths measured by the effective measurement sensor selected by the limiting unit 122 as the depth of the obstacle. Then, the interference determination unit 123 may determine that there is a risk of interference if the detected minimum depth has entered the warning area D1 or the automatic driving area D2.

  FIG. 13 is a flowchart showing processing of the construction machine 1 according to the fourth embodiment. In this flowchart, the same reference numerals are assigned to the same processes as those in the flowchart of FIG.

  In S1301 following S402, the limiting unit 122 selects an effective ultrasonic sensor based on the predicted approach position P1. Next, the effective ultrasonic sensor measures the depth of the object (S1302). Next, the interference determination unit 123 specifies the minimum depth among the depths measured by the effective ultrasonic sensor (S1303).

  Next, when it is determined that the minimum depth specified by the interference determination unit 123 has entered the warning area D1 (YES in S1304), the interference prevention unit 124 sounds the buzzer 130 to warn (S406). . If it is determined that the minimum depth specified by the interference determination unit 123 has entered the automatic driving area D2 (YES in S1305), the interference prevention unit 124 restricts the operation of the work device 4 (S408). . If NO in S1304 and NO in S1305, the process returns to S401.

  As described above, in the construction machine 1 according to the fourth embodiment, the plurality of ultrasonic sensors 310 are installed in the cab 31 so that the entire warning area D1 can be measured. Therefore, the plurality of ultrasonic sensors 310 can measure the entire warning area D1 without blind spots. In this aspect, the risk of interference is determined using the depth measured by the effective ultrasonic sensor. Therefore, useless measurement operation can be omitted.

(Embodiment 5)
The fifth embodiment is characterized in that the phase of the ultrasonic wave radiated from each ultrasonic sensor is controlled so that the directivity of the ultrasonic sensor array is directed to the predicted approach position P1.

  FIG. 14 is an external view of the construction machine 1 according to the fifth embodiment. As shown in FIG. 14, the ultrasonic sensor array 1710 is provided in the upper part of the front surface 31a. The ultrasonic sensor array 1710 includes a transmission side array 1711 and a reception side array 1712 as shown in FIG. In the transmission side array 1711, transmission elements 310 </ b> S that emit ultrasonic waves are arranged in an array of predetermined rows × predetermined columns. In the receiving array 1712, receiving elements 310R that receive ultrasonic waves are arranged in an array of predetermined rows × predetermined columns. Here, the transmitting element 310S arranged in the transmitting side array 1711 and the receiving element 310R arranged in the receiving side array 1712 have a one-to-one correspondence between the transmitting element 310S and the receiving element 310R in the same row and the same column. In addition, one ultrasonic sensor 310 is configured by one transmission element 310S and one reception element 310R corresponding thereto.

  FIG. 15 is a block diagram illustrating a system configuration of the construction machine 1 according to the fifth embodiment. 15 is different from FIG. 2 in that the measurement unit 110 includes ultrasonic sensor arrays 1710 and 1720 instead of the measurement sensors 111 and 112. The rest is the same.

  In FIG. 15, two ultrasonic sensor arrays 1710 and 1720 are provided. However, when the ultrasonic sensor array 1710 is configured as shown in FIG. 14, the ultrasonic sensor array 1720 is not necessary.

  FIG. 16 is a diagram for explaining the control of the ultrasonic sensor according to the fifth embodiment. In FIG. 14, the ultrasonic sensor array 1710 is disposed only at one position above the front surface 31 a of the cab 31, but the ultrasonic sensor is controlled by controlling the phase of the ultrasonic wave radiated from each ultrasonic sensor 310. The overall directivity of the array 1710 can be changed. In FIG. 16, in order to simplify the description, it is assumed that an ultrasonic sensor array 1710 is configured by three ultrasonic sensors 311, 312, and 313.

  In section (a) of FIG. 16, the ultrasonic sensors 311 to 313 emit ultrasonic waves in the same phase. In this case, since the phases of the ultrasonic components W1 to W3 in the direction A1 of 90 degrees with respect to the sensor surface S1600 of the ultrasonic sensor array 1710 are aligned, the ultrasonic components W1 to W3 in the direction A1 strengthen each other. As a result, ultrasonic waves having the maximum intensity in the direction A1 are emitted from the ultrasonic sensor array 1710.

  On the other hand, in the section (b), the second ultrasonic sensor 312 from the top and the third ultrasonic sensor from the top so that the phases of the ultrasonic components W1 to W3 are aligned in the direction A2 above the direction A1 by the angle θy. The phase with respect to the ultrasonic sensor 311 is shifted from the ultrasonic sensor 313. Thereby, the ultrasonic components W1 to W3 in the direction A2 are strengthened, and ultrasonic waves having the maximum intensity in the direction A2 are emitted from the ultrasonic sensor array 1710.

  Here, when the phase shift of the nth (n is an integer of 2 or more) ultrasonic sensor 310 from the top with respect to the first ultrasonic sensor 310 is α (n) (rad), α (n) Is represented by Formula (1).

α (n) = 2π (n−1) · d · sin θy / λ (1)
However, d represents the distance between the ultrasonic sensors 310 in meters, and λ represents the wavelength of ultrasonic waves emitted from the ultrasonic sensors in meters.

  Therefore, in the present embodiment, the limiting unit 122 adjusts the directivity of the ultrasonic wave in the entire ultrasonic sensor array 1710 by controlling the phase shift of each ultrasonic sensor 310 based on Expression (1). And limit the measurement range.

  More specifically, it is assumed that the predicted approach position P1 shown in FIG. 14 has an angle θy with respect to the front-rear direction. In this case, the limiting unit 122 sets the phase shift of the ultrasonic sensors 310 in the second and subsequent rows with respect to the phase of the ultrasonic sensor 310 in the first row as follows.

  That is, the limiting unit 122 sets the phase shift α (2) as α (2) = 2π · 1 · d · sin θy / λ for the ultrasonic sensor 310 in the second row, and sets the ultrasonic wave in the third row. For the sensor 310, the phase shift α (3) is set to α (3) = 2π · 2 · d · sin θy / λ,..., For the nth row ultrasonic sensor 310, the phase shift α ( n) is set to α (n) = 2π (n−1) · d · sin θy / λ. Thereby, ultrasonic waves with high intensity are radiated from the ultrasonic sensor array 1710 in the direction of the predicted approach position P1, and the measurement range can be efficiently limited.

  FIG. 17 is a flowchart showing the operation of the construction machine 1 in the fifth embodiment. In this flowchart, the same reference numerals are assigned to the same processes as those in the flowchart of FIG.

  In S1701 following S402, the limiting unit 122 adjusts the phase shift of the ultrasonic sensor 310 using Expression (1) so that the directivity of the ultrasonic sensor array 1710 is directed to the predicted approach position P1.

  Next, the ultrasonic sensor array 1710 measures the depth of the object (S1702). Here, the depth of the object is measured by each of the ultrasonic sensors 310 constituting the ultrasonic sensor array 1710.

  Next, the interference determination unit 123 specifies the minimum depth among the depths measured by the ultrasonic sensors 310 as the depth of the obstacle (S1703). Thereafter, the same processing as in the flowchart of FIG. 13 is repeated.

  Next, Modification 1 of Embodiment 5 will be described. FIG. 18 is a diagram illustrating an arrangement of the ultrasonic sensor array in the first modification of the fifth embodiment. The first modification is characterized in that an ultrasonic sensor array 1720 is provided in addition to the ultrasonic sensor array 1710.

  Although the front surface 31a is covered with the windshield 1703, if the ultrasonic sensor arrays 1710 and 1720 are disposed on the windshield 1703, the operator's field of view is blocked and the operability is deteriorated. Therefore, the ultrasonic sensor array 1710 is disposed on the upper pillar 1705 covering the windshield 1703, and the ultrasonic sensor array 1720 is disposed on the lower pillar 1706.

  Similar to the ultrasonic sensor array 1710, the ultrasonic sensor array 1720 includes a transmission side array 1721 and a reception side array 1722. The transmission-side array 1721 and the reception-side array 1722 have the same configuration as the transmission-side array 1711 and the reception-side array 1712, and thus description thereof is omitted.

  FIG. 19 is an external view of the construction machine 1 according to the first modification of the fifth embodiment. As shown in FIG. 19, in Modification 1, in addition to the ultrasonic sensor array 1710 provided at the upper part of the front surface 31a, the ultrasonic sensor array 1720 is arranged at the lower part of the front surface. Therefore, the measurement range of the entire ultrasonic sensor array 1710, 1720 can be further expanded.

  In the first modification, the limiting unit 122 selects an ultrasonic sensor array having a shorter distance from the predicted approach position P1 from the ultrasonic sensor arrays 1710 and 1720, and predicts the directivity of the selected ultrasonic sensor array. You may point to the position P1. Thereby, the depth of the object can be detected more accurately.

  Next, a second modification of the fifth embodiment will be described. FIG. 20 is a top view of the construction machine 1 according to the second modification of the fifth embodiment. Modification 2 is characterized in that the directivity of the ultrasonic sensor array 1710 is changed in the horizontal direction in addition to the vertical direction.

  For example, it is assumed that the predicted approach position P1 is in the direction A3 of θx from the sensor surface S1600 of the ultrasonic sensor array 1710 with respect to the front-rear direction as a reference. In this case, the limiting unit 122 adjusts the phase shift of each ultrasonic sensor 310 so that the directivity of the ultrasonic sensor array 1710 faces the direction A3. Note that the control of the phase shift that directs the directivity of the ultrasonic sensor array 1710 in the direction A3 can be easily estimated by assuming that the ultrasonic sensors 311 to 313 are arranged in the left-right direction in FIG.

  Specifically, θy in equation (1) is replaced with θx. Then, the limiting unit 122 sets the phase shift of the ultrasonic sensors 310 in the second and subsequent rows with respect to the phase of the ultrasonic sensor 310 in the first row as follows.

  That is, the limiting unit 122 sets the phase shift α (2) to α (2) = 2π · 1 · d · sin θx / λ for the ultrasonic sensor 310 in the second row, and sets the ultrasonic wave in the third row. For the sensor 310, the phase shift α (3) is set as α (3) = 2π · 2 · d · sin θx / λ,..., And the phase shift α ( n) is set to α (n) = 2π (n−1) · d · sin θx / λ. Thereby, ultrasonic waves with high intensity are radiated from the ultrasonic sensor array 1710 in the direction of the predicted approach position P1, and the measurement range can be efficiently limited.

  Furthermore, in the second modification, it is possible to direct the directivity of the ultrasonic sensor array 1710 in a direction that combines the left-right direction and the up-down direction.

  For example, a direction A2 (see FIG. 14) in which the vertical direction is θy with respect to the front-rear direction from the sensor surface S1600 of the ultrasonic sensor array 1710 and a left-right direction with respect to the front-rear direction from the sensor surface 1600 Is the predicted approach position P1 in the direction obtained by vector addition of the direction A3 (see FIG. 20) of the angle θx.

  In this case, the limiting unit 122 first sets a phase shift α (j) with respect to the ultrasonic sensor 310 in the first row and first column to α (j) = 2π (j -1) · d · sin θx / λ. Then, the limiting unit 122 sets the phase shift α (i) of the ultrasonic sensor 310 in the i-th row and j-th column to the ultrasonic sensor 310 in the first row and j-th column, α (i) = 2π (i−1). Set to d · sin θy / λ.

  As a result, the directivity of the ultrasonic sensor array 1710 can be directed in the direction obtained by vector addition of the direction A2 and the direction A3. Note that Modification 2 may be combined with Modification 1.

(Embodiment 6)
The sixth embodiment is characterized in that the ultrasonic sensor 310 is attached to the upper lattice member and the front lattice member in the construction machine 1 in which the plural ultrasonic sensors 310 shown in the fourth embodiment are arranged. In addition, in this Embodiment, the same thing as Embodiment 1-5 attaches | subjects the same code | symbol, and abbreviate | omits description.

  FIG. 21 is an external view of the construction machine 1 according to the sixth embodiment. A front lattice member 2102 and an upper lattice member 2101 are disposed on the front surface 31a and the upper surface 31c of the cab 31 of the construction machine 1, respectively. The ultrasonic sensors 310 are disposed on the front lattice member 2102 and the upper lattice member 2102.

  The ultrasonic sensor 310 receives the reflected waves while emitting ultrasonic waves at intervals of several tens of ms in order to detect the interference of obstacles with the front surface 31a and the upper surface 31c of the cab 31 in advance. Measure the distance.

  FIG. 22 is a diagram illustrating the directivity of the ultrasonic sensor 310. The directivity index of the ultrasonic sensor 310 is represented by the half-value angle β. The half-value angle β indicates an angle at which the sound level is attenuated to ½ of the maximum value when the angle is shifted with reference to the angle having the maximum sound level (sound intensity). If the half-value angle β is too wide, an error in the distance from the cab 31 to the object increases, which is not preferable. Therefore, it is preferable that the half-value angle β of the ultrasonic sensor 310 is small. In this case, since only one ultrasonic sensor 310 cannot cover the entire warning area D1, it is practical to use a plurality of ultrasonic sensors 310.

  Therefore, in the sixth embodiment, as shown in FIG. 23, the upper surface lattice member 2101 and the front surface lattice member 2102 are arranged on the front surface 31a and the upper surface 31c of the cab 31, and a plurality of upper surface lattice members 2101 and front surface lattice members 2102 are arranged on the front surface lattice member 2101 and front surface lattice member 2102. An ultrasonic sensor 310 was arranged.

  FIG. 23 is a view showing an arrangement example of the upper surface lattice member 2101 and the front surface lattice member 2102. As shown in FIG. 23, the upper surface lattice member 2101 is a lattice-like member provided above the upper surface 31c so as to cover the entire area of the upper surface 31c. The front lattice member 2102 is a lattice-shaped member provided in front of the front surface 31a so as to cover the entire area of the front surface 31a. Specifically, the upper surface lattice member 2101 and the front surface lattice member 2102 are configured by combining a plurality of vertical bars 2111 and a plurality of horizontal bars 2112 in a lattice shape.

  FIG. 24 is a diagram showing an arrangement pattern 1 of the ultrasonic sensors 310. In the arrangement pattern 1, the ultrasonic sensor 310 is arranged at a portion where the vertical bar 2111 and the horizontal bar 2112 intersect.

  Note that, based on the half-value angle β of the ultrasonic sensor 310, at least a range that can cover the detection of an object in the warning area D 1 is examined, and the lattice spacing and shape of the top lattice member 2101 and the front lattice member 2102 are determined. That's fine.

  FIG. 25 is a diagram showing an arrangement pattern 2 of the ultrasonic sensors 310. Here, it is assumed that the horizontal bar 2112 corresponds to a row, the vertical bar 2111 corresponds to a column, and the intersection of the horizontal bar 2112 and the vertical bar 2111 is represented by a row and a column. In the arrangement pattern 2, the ultrasonic sensors 310 are arranged at the intersections of the odd columns in the odd rows, and the ultrasonic sensors 310 are arranged at the intersections of the even columns in the even rows.

  FIG. 26 is a diagram showing an arrangement pattern 3 of the ultrasonic sensors 310. In the arrangement pattern 3, the upper surface lattice member 2101 and the front surface lattice member 2102 have a rhombus shape. Specifically, the upper surface lattice member 2101 and the front surface lattice member 2102 are configured by a rectangular frame body 2601 and a plurality of rod bodies 2602 incorporated so that a rhombus lattice is formed inside the frame body 2601. Yes. And the ultrasonic sensor 310 is arrange | positioned at each intersection of a grating | lattice.

  FIG. 27 is a diagram illustrating a state in which the ultrasonic sensor 310 attached to the construction machine 1 emits ultrasonic waves in the sixth embodiment.

  As shown in FIG. 27, the ultrasonic sensors 310 are arranged in a grid so that the measurement range 2201 can cover at least the entire region on the boundary surface L2. The blind spot of the ultrasonic sensor 310 does not occur in the warning area D1, and the construction machine 1 can issue a warning to the operator before the obstacle enters the automatic operation area D2.

  For construction machines equipped with attachments such as steel cutters, concrete crushers, and demolition grippers, front guards (protecting the front of the cab) and head guards (protecting the driver's upper surface) are provided as protective equipment to ensure safety. Is often provided.

  In order to arrange the ultrasonic sensor 310, a dedicated member may be attached to the construction machine 1, but if the front guard and the head guard originally provided as a protective equipment by the construction machine 1 are effectively used, the dedicated member is It becomes unnecessary.

  Therefore, in the present embodiment, the front lattice member 2102 is employed as the front guard, the upper lattice member 2101 is employed as the head guard, and the ultrasonic sensor 310 is disposed on both members. This prevents the operator's field of view from becoming worse than that of the protective equipment. As a result, in the present embodiment, it is possible to prevent an excessive increase in weight and cost of the construction machine 1.

  FIG. 28 is a diagram illustrating a state where the construction machine 1 according to the sixth embodiment limits the measurement range. The predicted approach position P1 is calculated in the same manner as in the fourth embodiment. Then, similarly to the fourth embodiment, the limiting unit 122 selects the ultrasonic sensor 310 that includes the predicted approach position P1 in the measurement range 2201 as an effective ultrasonic sensor.

  In the example of FIG. 28, the predicted approach position P1 is located in the measurement range 2201 of the ultrasonic sensor 310 located in the first row and the second row from the top among the ultrasonic sensors 310 attached to the front lattice member 2102. . Therefore, the limiting unit 122 selects the ultrasonic sensor 310 located in the first row and the second row from the top as an effective ultrasonic sensor. And the interference determination part 123 should just detect the minimum depth as the depth of an obstacle among the depths measured with the effective ultrasonic sensor. Then, the risk of interference is determined in the same manner as in the fourth embodiment.

C111, C112, E310 Measurement range D1 Warning area D2 Automatic operation area D80 Processing area G1 Distance image data P1 Predicted approach position θ1, θ2, θ3 Rotation angle 1 Construction machine 4 Working device 15 Boom 16 Arm 17 Attachment 31 Operation room 31a Front 31b Inclined surface 31c Upper surface 100 Acquisition unit 101, 102, 103 Angle sensor 110 Measurement unit 110a Actuator 111, 112 Measurement sensor 120 Controller 121 Prediction unit 122 Limiting unit 123 Interference determination unit 124 Interference prevention unit 130 Buzzer 310 Ultrasonic sensor 1710 Ultrasonic sensor Array 1720 Ultrasonic sensor array 2101 Top grid member 2102 Front grid member

Claims (15)

An interference prevention device for a construction machine comprising a working device capable of changing a posture and a cab,
A measurement unit that is attached to the cab and measures a distance from itself to an object located around the cab;
Using the distance measured by the measurement unit, an interference determination unit that determines the risk of interference with the driver's cab by an obstacle that is a gripped object of the work device or the work device;
When it is determined by the interference determination unit that there is a risk of the interference, an interference prevention unit that performs at least one of warning to a rider and operation restriction of the construction machine,
An acquisition unit for acquiring posture information indicating the posture of the working device;
A prediction unit that predicts an approach position from the cab to the obstacle using the posture information;
A limiting unit that limits a measurement range by the measurement unit according to a predicted approach position predicted by the prediction unit;
The said interference determination part is the interference prevention apparatus of the construction machine which determines the danger of the said interference using the distance of the said measured object in the measurement range limited by the said limitation part. The measurement unit includes a plurality of measurement sensors,
2. The construction machine interference preventing apparatus according to claim 1, wherein the limiting unit limits the measurement range by selecting a measurement sensor capable of measuring the predicted approach position from the plurality of measurement sensors.   The said limitation part is provided with the change part which changes the measurement direction of the said measurement part, and limits the said measurement range by orient | assigning the measurement direction of the said measurement part to the said prediction approach position using the said change part. The construction machine interference prevention device according to 2. The measurement unit includes a camera,
The construction machine according to any one of claims 1 to 3, wherein the limiting unit limits the measurement range by extracting a region including the predicted approach position from data indicating an image acquired by the camera. Interference prevention device.   5. The construction machine interference prevention device according to claim 1, wherein the measurement unit includes a distance sensor including a light source that emits infrared light and a camera that receives reflected light of the infrared light.   The construction machine interference prevention device according to claim 1, wherein the measurement unit includes a distance sensor including a stereo camera. The measurement unit includes a plurality of distance sensors installed in the operator's cab so that the entire area of the danger zone of interference set in the vicinity of the operator's cab can be measured,
The interference prevention device for a construction machine according to claim 1, wherein the interference determination unit determines the risk of interference using distances measured by the plurality of distance sensors in a measurement range limited by the limitation unit. The limiting unit limits the measurement range by selecting one or more distance sensors capable of measuring the predicted approach position from the plurality of distance sensors.
The construction machine interference prevention device according to claim 7, wherein the interference determination unit determines the risk of the interference using a distance measured by the selected one or more distance sensors.   The limiting unit limits the measurement range by controlling the phase of measurement waves radiated from each of the plurality of distance sensors so that the overall directivity of the plurality of distance sensors faces the predicted approach position. The construction machine interference prevention device according to claim 7.   The construction machine interference prevention device according to claim 9, wherein the plurality of distance sensors are arranged in a two-dimensional array.   The said interference determination part determines the danger of the said interference using the minimum distance among the distances which the said several distance sensor measured in the measurement range limited by the said limitation part. The construction machine interference prevention device according to Item 1.   The plurality of distance sensors according to any one of claims 7 to 11, wherein the plurality of distance sensors are constituted by ultrasonic sensors arranged on a lattice-like member installed on at least one of a front surface and an upper surface of the cab. The construction machine interference prevention device described.   13. The construction machine interference preventing apparatus according to claim 12, wherein the lattice-shaped member is at least one of a front guard and a head guard. The working device includes a boom swingably attached to the cab, an arm swingably attached to the boom, and an attachment swingably attached to the arm. With
The construction machine interference prevention device according to claim 1, wherein the acquisition unit acquires at least one of rotation angles of the boom, the arm, and the attachment as the posture information.   15. The construction machine interference prevention device according to claim 14, wherein the prediction unit predicts a distance between a tip of the arm or a tip of the attachment and the cab as the approach position.