Construction machine

Abstract

To provide a construction machine capable of determining whether or not a sensor for detecting an object functions normally before starting work.SOLUTION: A construction machine has an object detection sensor that is installed in a vehicle and detects a position of an object existing around the vehicle, a control device that outputs an object detection signal indicating that the object exists around the construction machine when the position of the object detected by the object detection sensor is within a predetermined first range, and a notification device to notify an operator of the detection of the object responding to the object detection signal output from the control device. The control device outputs a detection abnormal signal indicating the abnormality of the object detection sensor when the object detection sensor does not detect the object within a second range that is a detection range wider in lower direction than the first range when starting the construction machine. The notification device notifies the operator of the abnormality of the object detection sensor responding to the detection abnormal signal output from the control device.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a construction machine. [Background technology]

[0002] Known construction machines operating at work sites include those equipped with a function for detecting objects around the machine body for the purpose of improving safety, as described in Patent Document 1. Patent Document 1 describes a dirt determination device for an obstacle detection sensor in a work machine equipped with an obstacle detection sensor and a vehicle body information detection sensor, which calculates an undetected period during which the number of obstacles detected by the obstacle detection sensor is a predetermined number or less, and if the calculated undetected period is equal to or greater than a predetermined value, determines that the work machine is dirty if at least one of the following conditions is satisfied: the travel distance of the work machine during the undetected period and the steering duration period during which a steering amount equal to or greater than a predetermined value continues. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-179554 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above conventional technology, it is determined that the obstacle detection sensor is dirty when the driving distance or steering duration during a period in which the number of detected obstacles is below a predetermined number exceeds a predetermined value, that is, when the number of detected obstacles is less than expected despite driving or steering. However, because driving or steering is required before it is determined that the obstacle detection sensor is dirty, there is a concern that the operator may start or continue work without realizing that there is a high possibility that obstacles are not being detected.

[0005] The present invention has been made in consideration of the above, and aims to provide a construction machine that can determine whether a sensor that detects an object is functioning normally before starting work. [Means for solving the problem]

[0006] The present application includes multiple means for solving the above problem. One example is a construction machine equipped with an object detection sensor installed on a vehicle body for detecting the position of an object present around the vehicle body, a control device for outputting an object detection signal indicating that an object is present around the construction machine when the position of an object detected by the object detection sensor is within a predetermined first range, and an alarm device for notifying an operator that an object has been detected in response to the object detection signal output from the control device. When the object detection sensor does not detect an object within a second range which has a wider detection range downward than the first range, when the construction machine is started, the control device outputs a detection abnormality signal indicating that the object detection sensor is abnormal to the alarm device, and the alarm device notifies the operator that the object detection sensor is abnormal in response to the detection abnormality signal output from the control device. Effect of the Invention

[0007] According to the present invention, it is possible to determine whether or not a sensor that detects an object is functioning normally before starting work. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in a normal use mode. [Diagram 2] FIG. 1 is a rear view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in a normal use mode. [Diagram 3] FIG. 1 is a top view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in a normal use mode. [Figure 4]FIG. 1 is a side view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in an operation confirmation mode. [Diagram 5] FIG. 1 is a rear view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in an operation confirmation mode. [Figure 6] FIG. 1 is a top view showing a schematic external view of a hydraulic excavator, which is an example of a construction machine, together with a detection range in an operation confirmation mode. [Figure 7] FIG. 2 is a functional block diagram showing the processing functions of a controller together with related configurations. [Figure 8] 13 is a flowchart showing the contents of an object detection process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 8. In this embodiment, a hydraulic excavator will be described as an example of a construction machine, but the present invention can be applied to any machine equipped with a sensor for detecting surrounding objects. The present invention can also be applied to other construction machines, such as construction machines driven by power other than hydraulic power, such as electrically driven construction machines, and construction machines other than hydraulic excavators, such as wheel loaders.

[0010] Figures 1 to 6 are schematic diagrams showing the appearance of a hydraulic excavator, which is an example of a construction machine to which the present invention can be applied, with Figures 1 and 4 being side views, Figures 2 and 5 being rear views, and Figures 3 and 6 being top views.

[0011] 1 to 6, the hydraulic excavator 100 is roughly composed of a lower running body 101, an upper rotating body 102 which is rotatably mounted on the upper part of the lower running body 101 and which, together with the lower running body 101, constitutes the body of the hydraulic excavator 100, and an articulated front working machine 103 which is mounted in front of the upper rotating body 102.

[0012] The front working implement 103 is configured by rotatably connecting a plurality of driven members (boom 31, arm 32, and bucket 33) that each rotate in a vertical direction. A base end of the boom 31 is rotatably supported via a boom pin at the front of the upper rotating body 102, and one end of the arm 32 is rotatably connected to the tip of the boom 31 via an arm pin. In addition, a bucket 33 is rotatably connected to the other end (tip) of the arm 32 via a bucket pin. The boom 31 is driven by a boom cylinder 34, the arm 32 is driven by an arm cylinder 35, and the bucket 33 is driven by a bucket cylinder 36. Hereinafter, the boom cylinder 34, the arm cylinder 35, and the bucket cylinder 36 may be simply referred to as hydraulic actuators.

[0013] A crawler belt 11 stretched in the front-rear direction and a hydraulic motor 12 for traveling that drives the crawler belt 11 are provided on the left and right sides of the lower traveling body 101. A blade 13 that is driven to rotate in the vertical direction by a hydraulic actuator (not shown) is provided on one side of the front-rear direction of the lower traveling body 101. With the blade 13 lowered, it is possible to perform tasks such as pushing soil and leveling the ground.

[0014] The upper rotating body 102 is rotatably attached to the upper part of the lower traveling body 101, and is driven to rotate by a swing hydraulic motor (not shown). Hereinafter, the swing hydraulic motor may be simply referred to as a hydraulic actuator. Although not shown, an engine serving as a prime mover, a hydraulic pump driven by the engine, and a control valve for controlling the flow rate and direction of pressure oil discharged from the hydraulic pump and supplied to each hydraulic actuator in response to a signal output by a vehicle control device that controls the overall operation of the hydraulic excavator 100 are arranged on the vehicle body frame of the upper rotating body 102.

[0015] An operator's seat 104 is provided on the upper part of the upper rotating body 102, and the operator who operates the hydraulic excavator 100 sits on it. The operator's seat 104 is provided with a seat 21 on which the operator sits, a key switch 25 (see FIG. 7 below) for starting the engine (in other words, starting up the hydraulic excavator 100), and an operating lever device 22 for outputting an operating signal for operating each hydraulic actuator. A monitor 24 for notifying the operator of various information is provided in front of the operator's seat 104 at a position that does not obstruct the operator's view when the operator sits on the seat 21 is working with the front work implement 103. A stacked signal light (warning light) 23 for notifying the operator of information by turning on, off, flashing, or the like of a plurality of lamps of different colors arranged in a row is provided at a position that is assumed to be within the range of the operator's view when the operator sits on the seat 21 and does not obstruct the operator's view.

[0016] In addition, a buzzer 26 (see FIG. 7 below) that notifies the operator of various information by sound, and a speaker 27 (see FIG. 7 below) that notifies the operator of various information by voice are disposed in or around the driver's seat 104.

[0017] An object detection sensor 105 for detecting whether or not an object is present within a predetermined detection range is provided behind the driver's seat 104 of the upper rotating body 102 constituting the body of the hydraulic excavator 100 (for example, at the upper rear end of the body cover and above the counterweight, in other words, on the upper surface of the upper rotating body 102). The object detection sensor 105 is, for example, a distance measuring sensor such as an infrared sensor, and measures the distance and position of an object present within a range that can be detected according to specifications. The detection result of the object detection sensor 105 is sent to a controller 200 described later, and the position or distance of the detected object is compared with a predetermined detection range to determine whether or not an object is present within the detection range. The rear of the upper rotating body 102 is covered by an engine cover that is disposed continuously with the body cover and is provided so as to be able to slide open and close or turn open and close in the vertical direction. When the engine cover is in the closed position, it is outside the detection range of the object detection sensor 105, and when it is in the open position, it overlaps with the detection range of the object detection sensor 105.

[0018] In this embodiment, an infrared sensor is described as an example of object detection sensor 105, but the present invention is not limited to this. For example, the present invention can be applied to any distance measurement sensor such as LiDAR (Light Detection and Ranging), which measures distance by measuring scattered light from an object when irradiated with a laser, or millimeter wave radar, which measures distance by measuring reflected waves from an object when irradiated with millimeter waves.

[0019] FIG. 7 is a functional block diagram showing the processing contents of the controller.

[0020] The controller 200 controls the object detection process that detects objects around the hydraulic excavator 100 and notifies the operator based on the detection results from the object detection sensor 105, and is disposed at a predetermined position on the upper rotating body 102.

[0021] 7, the controller 200 includes a detection mode control unit 201, a detection range setting unit 202, an object detection unit 203, and a notification control unit 204.

[0022] The detection mode control unit 201 selectively switches the state (detection mode) of the controller 200 between an operation confirmation mode for confirming whether the object detection sensor 105 is operating normally or a normal use mode for detecting objects around the hydraulic excavator 100 using the object detection sensor 105, based on a start signal from the key switch 25 for starting the engine (in other words, for starting the hydraulic excavator 100) and a detection result from the object detection unit 203. Specifically, when a start signal is output from the key switch 25, the detection mode control unit 201 switches the detection mode to the operation confirmation mode, and when an object is detected by the object detection unit 203 in the operation confirmation mode (in other words, when an object detection signal indicating that an object has been detected is received from the object detection unit 203), the detection mode control unit 201 determines that the object detection sensor 105 is operating normally in the operation confirmation mode and switches to the normal use mode. Furthermore, when an object detection signal is not received from the object detection unit 203 in the operation confirmation mode, the operation confirmation mode is continued.

[0023] The detection range setting unit 202 sets the object detection range according to the detection mode set by the detection mode control unit 201. Figures 1 to 3 show an example of setting the detection range 105a (first range) in the normal use mode, and Figures 4 to 6 show an example of setting the detection range 105b (second range) in the operation confirmation mode.

[0024] 1 to 3, the detection range 105a in the normal use mode extends diagonally downward and spreads in a planar manner in the left-right direction when viewed rearward from the object detection sensor 105, and is set so as not to include the ground 300 (the contact surface of the tracks 11) surrounding the hydraulic excavator 100 at the work site. In other words, the detection range 105a is set closer to the object detection sensor 105 than the ground 300.

[0025] 4 to 6, the detection range 105b in the operation confirmation mode is set so as to extend diagonally downward and spread in a plane in the left-right direction when viewed rearward from the object detection sensor 105, and to include the ground surface 300 (the contact surface of the tracks 11) around where the hydraulic excavator 100 is located at the work site. The detection range 105b is set based on, for example, the maximum distance that is measurable based on the specifications of the object detection sensor 105.

[0026] Although not shown in the drawings, in the normal use mode and the operation check mode, from the viewpoint of ensuring detection accuracy and suppressing erroneous detection, the vicinity of the object detection sensor 105 is excluded from the detection range. Specifically, for example, the range of the distance to the nearest structure of the hydraulic excavator 100 in the direction along the detection ranges 105a, 105b of the object detection sensor 105 (for example, a pillar supporting the roof disposed above the driver's seat 104) is excluded from the detection range.

[0027] The object detection unit 203 determines whether or not an object is present within the detection ranges 105a, 105b based on the detection result of the object detection sensor 105 and the detection ranges 105a, 105b set by the detection range setting unit 202, and outputs the determination result to the detection mode control unit 201 and the notification control unit 204.

[0028] When the detection mode control unit 201 switches to the normal use mode and the detection range setting unit 202 sets the detection range 105a, it is determined whether or not the position of the object detected by the object detection sensor 105 is within the detection range 105a, that is, whether or not an object is present within the detection range 105a. If it is determined that an object is present within the detection range 105a, an object detection signal indicating that an object has been detected is output as a detection result to the detection mode control unit 201 and the notification control unit 204. Note that in this embodiment, a case will be described in which no signal is output when no object is present within the detection range 105a, but it may be configured to output a signal indicating that an object is not detected.

[0029] Furthermore, when the detection mode control unit 201 switches to the operation confirmation mode and the detection range setting unit 202 sets the detection range 105b, the object detection sensor 105 judges whether or not the position of the object detected by the object detection sensor 105 is within the detection range 105b, that is, whether or not an object is present within the detection range 105b. At this time, since the detection range 105b is set so as to include the ground 300 surrounding the hydraulic excavator 100 at the work site, if the object detection sensor 105 is operating normally, it judges that the ground 300 as an object is present within the detection range 105a, and outputs an object detection signal indicating that an object has been detected as a detection result to the detection mode control unit 201 and the notification control unit 204.

[0030] On the other hand, if the ground 300 as an object is not detected due to an abnormality in the object detection sensor 105, it is determined that no object is present within the detection range 105b. For example, if the object detection sensor 105 is an infrared sensor, possible abnormalities in the object detection sensor 105 include a malfunction of the infrared sensor itself, as well as the adhesion of dirt such as water droplets, dust, or mud to the lens surface of the infrared emitting section or the reflected wave receiving section. In this case, the infrared rays emitted from the infrared sensor are blocked by the dirt on the lens surface before they reach the target object, and the infrared rays are not emitted correctly.

[0031] In this embodiment, a case will be described as an example in which no signal is output when no object is present within detection range 105a, but the configuration may be such that a signal indicating that no object is detected is output.

[0032] Depending on the detection mode set by the detection mode control unit 201 and the detection result from the object detection unit 203, the notification control unit 204 outputs an object detection signal indicating that there is an obstacle (object) behind the hydraulic excavator 100, or a detection abnormality signal indicating that the object detection sensor 105 is not operating normally, to notification devices such as the monitor 24, stacked signal light 23, buzzer 26, speaker 27, etc.

[0033] For example, when the detection mode set by the detection mode control unit 201 is the operation confirmation mode, if the object detection unit 203 determines that no object is present in the detection range 105b, it outputs to the alarm device a detection abnormality signal indicating that the object detection sensor 105 is not operating normally. Also, when the detection mode control unit 201 determines that an object is present in the detection range 105b in the operation confirmation mode, it switches to the normal use mode, and when an object is present in the detection range 105a, it outputs to the alarm device an object detection signal indicating that there is an obstacle (object) behind the hydraulic excavator 100.

[0034] The processing principle of the notification control unit 204 is as follows. That is, for example, when the operation confirmation mode is switched to in response to a start signal from the key switch 25 and the detection range 105b is set, if the object detection sensor 105 is operating normally, it is determined that at least the ground 300 (object) is within the range of the detection range 105b. Also, if the hydraulic excavator 100 is placed in, for example, a hangar, it is determined that an object such as a wall or a pillar is within the range of the detection range 105b. That is, if it is determined that an object exists within the detection range 105b in the operation confirmation mode, it can be said that the object detection sensor 105 is operating normally. In other words, if it is determined that no object exists within the detection range 105b, it can be said that the object detection sensor 105 is not operating normally.

[0035] When no signal is output from the notification control unit 204, the stacked signal light 23, which is a notification device, has a lamp (e.g., a green lamp) indicating that the device is in operation lit, and the buzzer 26 is in a muted state. When a detection abnormality signal is output from the notification control unit 204, the stacked signal light 23 flashes a lamp (e.g., a red lamp) indicating that an abnormality has occurred, and the buzzer 26 emits a continuous warning sound, thereby notifying the operator that some abnormality has occurred in the object detection sensor 105 and that the object detection sensor 105 is not operating normally. When an object detection signal is output from the notification control unit 204, the stacked signal light 23 lights a lamp (e.g., a red lamp) indicating that an abnormality has occurred, and the buzzer 26 emits an intermittent warning sound, thereby notifying the operator that there is an obstacle, such as earth and sand, a structure, or a worker, behind the hydraulic excavator 100, which is likely to be in the blind spot of the operator operating the excavator in the driver's seat 104.

[0036] The monitor 24 is a display device that displays images and text according to the notification content, and when a detection abnormality signal is output from the notification control unit 204, the monitor 24 notifies the operator by displaying information (images and text) that some abnormality has occurred in the object detection sensor 105 and that it is not operating normally. In addition, when an object detection signal is output from the notification control unit 204, the monitor 24 notifies the operator by displaying information indicating that there is an obstacle, such as a worker, behind the hydraulic excavator 100.

[0037] Similarly, when a detection abnormality signal is output from the notification control unit 204, the speaker 27 notifies the operator by voice that some abnormality has occurred in the object detection sensor 105 and that the object detection sensor 105 is not operating normally. Moreover, when an object detection signal is output from the notification control unit 204, the speaker 27 notifies the operator by voice that there is an obstacle, such as a worker, behind the hydraulic excavator 100.

[0038] In the present embodiment, the case where an object detection signal or a detection abnormality signal is output to an alarm device to notify an operator of information has been described as an example, but the present invention is not limited to this. For example, when the controller 200 outputs an object detection signal or a detection abnormality signal, it may output a deceleration control signal for decelerating the operating speed of the hydraulic excavator 100 (construction machine) or a stop control signal for stopping the operation to a vehicle body control device that controls the overall operation of the hydraulic excavator 100, and a signal may be output from the vehicle body control device to a control valve or the like in response to the deceleration control signal or the stop control signal, thereby stopping the operation of the hydraulic excavator 100 or slowing down the operating speed. Also, it may be configured such that the controller 200 outputs an object detection signal or a detection abnormality signal to the vehicle body control device, and a signal is output from the vehicle body control device to a control valve or the like in response to the object detection signal or the detection abnormality signal, thereby stopping the operation of the hydraulic excavator 100 or slowing down the operating speed. It is also possible to consider the controller 200 and the vehicle body control device as an integrated control device, and to consider that this control device outputs a signal to a control valve or the like in response to the detection result of the object detection sensor 105.

[0039] FIG. 8 is a flowchart showing the contents of the object detection process.

[0040] In FIG. 8, when the key switch 25 is operated and a start signal is output (step S100), the controller 200 starts up in a state switched to the operation confirmation mode, and determines whether or not any object has been detected in the detection range 105b (step S120).

[0041] If the determination result in step S120 is NO, i.e., if an object is not detected in the detection range 105b, the alarm device notifies the operator that the object detection sensor 105 is malfunctioning (i.e., not operating normally) (step S121), and the process ends.

[0042] If the determination result in step S120 is YES, that is, if an object is detected in detection range 105b, the system transitions to normal use mode (step S130). In the normal use mode, it is determined whether the position of the object detected by object detection sensor 105 is within detection range 105a (step S140), and if the determination result is NO, that is, if it is determined that there is no object within detection range 105a, the process of step S140 is repeated and the system waits.

[0043] Furthermore, if the determination result in step S140 is YES, that is, if it is determined that an object is present within detection range 105a, an alarm device is activated to notify the operator that there is an obstacle, such as a worker, behind the hydraulic excavator 100 (step S150), and the process returns to step S140.

[0044] The effects of the present embodiment configured as above will be described.

[0045] If the object detection sensor is not working properly due to dirt or other reasons, there is a high possibility that obstacles will not be detected, and it is necessary to prevent the operator from starting or continuing work without realizing this condition.

[0046] Therefore, in this embodiment, when the hydraulic excavator 100 is started, it is determined whether or not the object detection sensor 105 has detected an object, and if it is determined that an object has not been detected, a detection abnormality signal indicating that the object detection sensor 105 is abnormal is output to an alarm device (e.g., stacked signal light 23, monitor 24, buzzer 26, speaker 27), and the alarm device is configured to notify the operator that the object detection sensor 105 is abnormal in response to the detection abnormality signal output from the controller 200, so that it is possible to determine whether the sensor that detects objects is functioning normally before work begins.

[0047] <Additional Notes> The present invention is not limited to the above-described embodiment, but includes various modifications and combinations within the scope of the present invention.

[0048] For example, in this embodiment, a case has been described in which one object detection sensor 105 is installed so that the detection range is behind the hydraulic excavator 100, but this is not limited to this. For example, multiple object detection sensors may be provided whose detection ranges are on the left and right sides of the hydraulic excavator 100, and configured to perform similar processing.

[0049] Furthermore, the present invention is not limited to those having all the configurations described in the above embodiments, and includes those in which some of the configurations are omitted. Furthermore, the above-mentioned configurations, functions, etc. may be realized in part or in whole by designing, for example, an integrated circuit. Furthermore, the above-mentioned configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. [Explanation of symbols]

[0050] 11...track, 12...traveling hydraulic motor, 13...blade, 21...seat, 22...operating lever device, 23...stacked signal light, 24...monitor, 25...key switch, 26...buzzer, 27...speaker, 31...boom, 32...arm, 33...bucket, 34...boom cylinder, 35...arm cylinder, 36...bucket cylinder, 100...hydraulic excavator, 101...lower running body, 102...upper rotating body, 103...front work machine, 104...driver's seat, 105...object detection sensor, 105a, 105b...detection range, 200...controller, 201...detection mode control unit, 202...detection range setting unit, 203...object detection unit, 204...alert control unit, 300...ground

Claims

1. An object detection sensor installed on a vehicle body for detecting the position of an object existing around the vehicle body; A control device that outputs an object detection signal indicating that an object exists around the vehicle body when the position of the object detected by the object detection sensor is within a predetermined first range; In a construction machine comprising a notification device that notifies an operator that an object has been detected in response to the object detection signal output from the control device, When starting the vehicle body, if the object detection sensor does not detect an object within a second range where the detection range downward from the first range is wider, the control device outputs a detection abnormality signal indicating that the object detection sensor is abnormal to the notification device. The construction machine is characterized in that the notification device notifies an operator that the object detection sensor is abnormal in response to the detection abnormality signal output from the control device.

2. In the construction machine according to Claim 1, The first range is set to a range that does not include the ground contact surface of the construction machine, The construction machine is characterized in that the second range is set to a range that includes the ground contact surface.

3. In the construction machine according to Claim 2, A lower traveling body; An upper swing body rotatably provided on the upper part of the lower traveling body; Comprising, The construction machine is characterized in that the object detection sensor is attached to the upper surface of the upper swing body and is installed so that the detection direction extends obliquely downward.

4. In the construction machine according to Claim 1, The notification device is at least one of a buzzer that emits a sound according to a signal output by the control device, a stacked signal lamp in which a plurality of electric lamps of different colors that light up or blink according to a signal output by the control device are arranged side by side, and a speaker that outputs a voice according to a signal output by the control device. The construction machine is characterized by this.

5. In the construction machine according to Claim 1, A working machine; A hydraulic actuator that drives the working machine; A control valve that controls the flow rate and direction of the pressure oil supplied to the hydraulic actuator according to a signal output by the control device Comprising, When outputting the detection abnormality signal, the control device outputs a deceleration control signal for decelerating the operating speed of the construction machine or a stop control signal for stopping the operation to the control valve. The construction machine is characterized by this.

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