Work machine

Abstract

The invention provides a work machine. The present invention provides a technique capable of detecting, with high precision, the proximity of an object to a work unit on the basis of image data captured by an imaging unit even when a work machine is used outdoors. The work machine disclosed in this specification may be provided with: a work unit; a prime mover that drives the working unit; an imaging unit that captures an image of a range in the vicinity of the working unit; and a control unit. The work machine can operate in a normal mode in which the work machine operates as usual and a safe mode in which the work machine operates more safely than in the normal mode. The control unit may be configured to operate the work machine in the safe mode when it is determined that an object approaches the work unit on the basis of the number of pixels, among the pixels included in the image data captured by the imaging unit, of which the hue when expressed in an HSV format is within a predetermined range.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a working machine. Background Art

[0002] Japanese Patent Application Laid-Open No. 2010-23186 discloses a working machine, which includes: a working unit; a prime mover that drives the working unit; a camera that captures a range near the working unit; and a control unit. The working machine can operate in a normal mode in which the working machine operates as usual and a safe mode in which the working machine operates more safely than in the normal mode. The control unit is configured to cause the working machine to operate in the safe mode when it is determined that an object is approaching the working unit based on the number of pixels whose color values ​​when expressed in YUV format are specified values ​​among the pixels included in the image data captured by the camera. Summary of the invention

[0003] Problem that the invention aims to solve

[0004] When a work machine is used outdoors, image data is sometimes captured in a bright environment and sometimes in a dark environment. If the image data is represented in YUV format or RGB format, even when capturing objects of the same color, different color values ​​may be obtained depending on the brightness at the time of capturing. Therefore, when a work machine is used outdoors, it may be difficult to accurately detect the approach of an object such as the user's body to the work unit. This specification provides a technology that can accurately detect the approach of an object to the work unit based on image data captured by a camera unit, even when a work machine is used outdoors.

[0005] Solutions for solving problems

[0006] The working machine disclosed in this specification may also include: a working unit; a prime mover that drives the working unit; a camera that captures a range near the working unit; and a control unit. The working machine may also be capable of operating in a normal mode in which the working machine operates as usual and a safe mode in which the working machine operates more safely than in the normal mode. The control unit may also be configured to cause the working machine to operate in the safe mode when it is determined that an object is approaching the working unit based on the number of pixels whose hue when expressed in HSV format is within a predetermined range among the pixels included in the image data captured by the camera.

[0007] When the image data captured by the camera unit is expressed in the HSV format of hue, saturation, and brightness, objects of the same color have the same hue even if the brightness at the time of capturing is different. Therefore, according to the above configuration, even when the working machine is used outdoors, it is possible to detect the approach of an object to the working unit with high accuracy based on the image data captured by the camera unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a block diagram showing a schematic configuration of a working machine 2 according to the embodiment.

[0009] Figure 2 This is a perspective view of the working unit 8 of the working machine 2 according to the embodiment as viewed from the upper right front.

[0010] Figure 3 It is a longitudinal sectional view of a state where the movable blade 34 of the working unit 8 of the working machine 2 of the embodiment is opened relative to the fixed blade 32 .

[0011] Figure 4 This is a perspective view of the internal structure of the working unit 8 of the working machine 2 of the embodiment as viewed from the upper right front.

[0012] Figure 5 It is a longitudinal sectional view of a state where the movable blade 34 of the working unit 8 of the working machine 2 of the embodiment is closed relative to the fixed blade 32 .

[0013] Figure 6 This is a perspective view of the working unit 8 of the working machine 2 according to the embodiment as viewed from the upper left front.

[0014] Figure 7 This is a perspective view showing a state of cutting a branch 82 using the working machine 2 of the embodiment as viewed from the rear upper side.

[0015] Figure 8 This is a flowchart of the approach determination process performed by the control unit 14 of the working machine 2 of the embodiment.

[0016] Fig. 9 This is an example of the image data ID captured by the camera 74 when the camera 74 is not blocked in the working machine 2 of the embodiment.

[0017] Fig.10 This is an example of image data ID captured by the camera 74 when the camera 74 is blocked by the obstacle 84 in the working machine 2 of the embodiment. DETAILED DESCRIPTION

[0018] With reference to the accompanying drawings, representative and non-limiting specific examples of the present invention are described in detail below. This detailed description is intended only to show the details of preferred examples for implementing the present invention to those skilled in the art, and is not intended to limit the scope of the present invention. In addition, the disclosed additional features and technical solutions can be used separately or together with other features and technical solutions to provide further improved working machines, methods of use thereof, and methods of manufacturing thereof.

[0019] In addition, the combination of features and processes disclosed in the following detailed description is not necessary in the broadest sense for practicing the present invention, but is only recorded for the purpose of specifically illustrating the representative specific examples of the present invention. Moreover, when providing additional and useful embodiments of the present invention, the various features of the following representative specific examples and the various features described in the claims do not necessarily have to be combined in the specific examples or the order in which they are listed.

[0020] Different from the structures of the features described in the embodiments and / or claims, all the features described in this specification and / or claims are intended to be disclosed individually and independently of each other as limitations on the original disclosure and the specific matters described in the claims. In addition, all numerical ranges and records involving groups or groups are intended to disclose their intermediate structures as limitations on the original disclosure and the specific matters described in the claims.

[0021] In one or more embodiments, the control unit may be configured to determine whether the object is close to the working unit based on the number of pixels whose hue is within the predetermined range and whose saturation is above a threshold when expressed in HSV form, among the pixels contained in the image data captured by the camera unit.

[0022] When the image data captured by the camera unit is expressed in HSV format, the hue of a color with low saturation, such as white, black, and gray, may have the same value as the hue of another color with high saturation (e.g., purple). Therefore, when determining whether a pixel corresponds to an object based only on the hue of the pixel, it is possible that a pixel with a low saturation color is mistakenly determined as a pixel corresponding to the object. According to the above configuration, since it is determined whether the object is close to the working unit based on the number of pixels whose hue is within a predetermined range and whose saturation is above a threshold, it is possible to suppress false detection caused by the reflection of a color with low saturation.

[0023] In one or more embodiments, the control unit may set the threshold value to a lower value as the brightness of pixels included in the image data captured by the imaging unit when expressed in HSV format is higher.

[0024] Generally speaking, when the image data is captured in a bright environment, the saturation of the pixels corresponding to the object tends to be low, and when the image data is captured in a dark environment, the saturation of the pixels corresponding to the object tends to be high. According to the above configuration, since the saturation threshold is set to a lower value as the brightness of the pixels included in the image data is higher, it is possible to more reliably detect the approach of the object to the working unit.

[0025] In one or more embodiments, the predetermined range may be a range of 230° to 360°.

[0026] When the working machine is used outdoors, the blue of the sky, the green of leaves and grass, and the brown of branches and trunks may be reflected in the image data captured by the camera unit. The hues of these colors are within the range of 0° to 230°, and colors with hues within the range of 230° to 360° (e.g., purple) are hardly reflected in the image data. According to the above configuration, by setting the hue of the color of the object within the range of 230° to 360°, it is possible to detect the approach of the object to the working unit with high accuracy.

[0027] In one or more embodiments, the working machine may further include a housing that supports the working unit and the camera unit and is held by a user. The working unit may include a fixed tool and a movable tool that can rotate relative to the fixed tool around a rotation axis extending in the left-right direction and is driven by the prime mover.

[0028] The above-mentioned working machine functions as a pruning shear for cutting branches, etc. When using the above-mentioned working machine to cut branches, the user sometimes performs the operation while holding the housing with one hand and holding the branch with the other hand. According to the above-mentioned configuration, by wearing a glove with a color (e.g., purple) within a predetermined range of hues on the other hand, the working machine can be operated in a safe mode when the glove as an object approaches the working part. The safety of the user can be ensured.

[0029] In one or more embodiments, the imaging unit may be arranged on the upper surface side of the housing.

[0030] In a structure in which the working part has a fixed tool and a movable tool, if the camera part is on the right surface side (or left surface side) of the shell, although the area on the right side (or left side) of the working part enters the field of view of the camera part, the area on the left side (or right side) of the working part is blocked by the working part and does not enter the field of view of the camera part, so it is difficult to shoot the areas on the left and right sides of the working part. In addition, if the camera part is on the lower surface side of the shell, although the areas on the left and right sides of the working part can be shot, the camera part will protrude downward from the shell, which is easy to hinder the operation. According to the above-mentioned structure, since the camera part is arranged on the upper surface side of the shell, it is possible to shoot the areas on the left and right sides of the working part. In addition, it is possible to prevent the working part from protruding downward from the shell and hindering the operation.

[0031] In one or more embodiments, when the movable blade is maximally opened relative to the fixed blade, the camera unit may be arranged below an upper end of the movable blade when the longitudinal direction of the housing is horizontal.

[0032] Even when the camera unit is disposed on the upper surface side of the housing and the camera unit protrudes upward from the housing, if the camera unit is disposed at a position lower than the upper end of the movable tool when the movable tool is opened to the maximum extent, it is not easy to hinder the operation. According to the above-mentioned structure, even when the camera unit protrudes upward from the housing, it is possible to suppress the camera unit from hindering the operation.

[0033] In one or more embodiments, a lighting unit may be further provided, the lighting unit being supported by the housing and illuminating an area near the working unit.

[0034] According to the above configuration, even in a dark environment, image data can be captured in a state where the area near the working unit is illuminated by the lighting unit, so that image data can be acquired under the same conditions as when image data is captured in a bright environment. Deviations in detection accuracy caused by differences in ambient brightness can be suppressed.

[0035] In one or more embodiments, the lighting unit may include a right lighting unit arranged on the right surface side of the casing and a left lighting unit arranged on the left surface side of the casing.

[0036] In a structure in which the working part has a fixed cutter and a movable cutter, if the working machine has only a right lighting unit (or a left lighting unit), although the area on the right side (or the left side) of the working part is illuminated, the area on the left side (or the right side) of the working part is not illuminated, so it is difficult to illuminate the areas on the left and right sides of the working part. According to the above-mentioned structure, since the working machine has both the right lighting unit and the left lighting unit, it is possible to appropriately illuminate the areas on the left and right sides of the working part.

[0037] In one or more embodiments, the control unit may separately determine a first pixel arranged at a position corresponding to the fixed tool and a second pixel arranged at a position not corresponding to the fixed tool and the movable tool, among the pixels included in the image data, and may also determine whether the camera unit is blocked by an obstacle based on the hue, saturation and / or brightness of the first pixel and the second pixel when expressed in HSV form.

[0038] When the camera unit is not blocked by an obstacle, the first pixel at the position corresponding to the fixed tool is always reflected in the same color (i.e., the color of the fixed tool), and the second pixel at the position not corresponding to the fixed tool or the movable tool is reflected in the color of the background. In this case, the hue, saturation, and brightness become different values ​​in the first pixel and the second pixel. In contrast, when the camera unit is blocked by an obstacle, the color of the same obstacle is reflected in the first pixel at the position corresponding to the fixed tool or the second pixel at the position not corresponding to the fixed tool or the movable tool. In this case, the hue, saturation, and brightness become approximately the same values ​​in the first pixel and the second pixel. According to the above-mentioned configuration, it is possible to appropriately determine whether the camera unit is blocked by an obstacle based on the hue, saturation, and / or brightness of the first pixel at the position corresponding to the fixed tool and the second pixel at the position not corresponding to the fixed tool or the movable tool.

[0039] In one or more embodiments, the left-right viewing angle of the imaging unit may be within a range of 60° to 120°.

[0040] If the field of view in the left-right direction is too wide, the object will be reflected in the image data even if the object is not that close to the working unit in the left-right direction. On the contrary, if the field of view in the left-right direction is too narrow, the object will not be reflected in the image data until the object is very close to the working unit in the left-right direction. According to the above configuration, it is possible to appropriately detect whether the object is close to the working unit in the left-right direction.

[0041] In one or more embodiments, the vertical field angle of the imaging unit may be within a range of 45° to 90°.

[0042] If the vertical viewing angle is too wide, the object will be reflected in the image data even if the object is not that close to the working unit in the vertical direction. On the contrary, if the vertical viewing angle is too narrow, the object will not be reflected in the image data until the object is very close to the working unit in the vertical direction. According to the above configuration, it is possible to appropriately detect whether the object is close to the working unit in the vertical direction.

[0043] In one or more embodiments, a shutter speed of the imaging unit may be in a range of 0.1 ms to 2 ms.

[0044] According to the above configuration, when the working machine is used outdoors, image data can be captured with appropriate brightness.

[0045] In one or more embodiments, the safety mode may include a first safety mode that operates more safely than the normal mode and a second safety mode that operates more safely than the first safety mode. The control unit may be configured to cause the working machine to operate in the first safety mode when it is determined that the object is approaching the working unit at a first proximity level based on the number of pixels whose hue is within the predetermined range among the pixels included in the image data captured by the camera unit. The control unit may be configured to cause the working machine to operate in the second safety mode when it is determined that the object is approaching the working unit at a second proximity level that is closer than the first proximity level based on the number of pixels whose hue is within the predetermined range among the pixels included in the image data captured by the camera unit.

[0046] According to the above configuration, the working machine can be operated in a safer mode in stages according to the approach level of the object to the working unit.

[0047] (Example)

[0048] like Figure 1 As shown, the working machine 2 includes a battery unit 4, a switch unit 6, and a working unit 8. The working machine 2 is, for example, a pruning shear used for cutting stems, branches, etc. of flowers, plants, trees, etc. The battery unit 4 includes a shoulder strap and a waist belt, which are attached to a harness (not shown) worn by a user. The switch unit 6 is attached to the waist belt of the harness. The working unit 8 is used by the user holding it with one hand. The battery unit 4 and the switch unit 6 are electrically connected via a cable 10. The switch unit 6 and the working unit 8 are electrically connected via a connecting line 12.

[0049] The battery unit 4 includes a control unit 14 and a battery pack 16. The control unit 14 includes a CPU, a ROM, a RAM, etc., and controls the operation of the working machine 2. The battery pack 16 is detachably mounted on the battery unit 4. The battery pack 16 includes a secondary battery such as a lithium ion battery. The working machine 2 operates using the power supplied from the battery pack 16.

[0050] The switch unit 6 includes a main power switch 18, an indicator light 20, and a buzzer 22. The main power switch 18 receives an operation from a user to switch the main power of the working machine 2 on / off. The indicator light 20 indicates the on / off state of the main power, the presence or absence of abnormality, etc. to the user of the working machine 2. The buzzer 22 emits a warning sound to the user of the working machine 2.

[0051] like Figure 2 As shown, the operation unit 8 includes a housing 24. The housing 24 has a length direction in the front-to-back direction. A handle 26 for the user to hold with one hand is formed on the housing 24. A connector 27 for detaching and assembling the connection line 12 is provided at the rear end of the housing 24. A trigger 28 that can be operated by the user and a guard 30 that protects the user's fingers operating the trigger 28 are provided at a portion of the housing 24 that is closer to the front than the handle 26. The trigger 28 and the guard 30 are provided on the lower surface side of the housing 24. A fixed tool 32 and a movable tool 34 that rotates relatively to the fixed tool 32 are provided at the front end of the housing 24. The movable tool 34 is arranged adjacent to the right side of the fixed tool 32.

[0052] like Figure 3 As shown, an electric motor 36, a power transmission unit 38, and a trigger position detection unit 40 are housed inside the housing 24. The electric motor 36 is, for example, a DC brushless motor, such as a coreless motor. The electric motor 36 is disposed inside the handle 26. An output shaft 42 of the electric motor 36 extends forward.

[0053] The power transmission unit 38 includes a speed reduction mechanism 44, a screw shaft 46, a nut 48, a nut housing 50, and a connecting rod arm 52. The speed reduction mechanism 44 is, for example, a planetary gear mechanism, which reduces the rotation of the output shaft 42 and transmits it to the screw shaft 46. The screw shaft 46 and the nut 48 constitute a so-called ball screw mechanism. The nut 48 is fixed to the nut housing 50. When the screw shaft 46 rotates in the forward direction, the nut 48 and the nut housing 50 move toward the rear relative to the housing 24. When the screw shaft 46 rotates in the reverse direction, the nut 48 and the nut housing 50 move toward the front relative to the housing 24.

[0054] The fixed blade 32 includes a lower blade portion 54 and a support portion 56. The support portion 56 is fixed to the housing 24. The movable blade 34 includes an upper blade portion 58 and a rod portion 60. The movable blade 34 is rotatably connected to the fixed blade 32 by a bolt 62 extending in the left-right direction.

[0055] like Figure 4 As shown in FIG. 1 , the link arm 52 extends in the front-rear direction. The rear end of the link arm 52 is rotatably connected to the nut 48 by means of a pin 64 extending in the left-right direction. The front end of the link arm 52 is rotatably connected to the rod 60 by means of a pin 66 extending in the left-right direction. Figure 5 As shown in FIG. 1 , when the nut 48 and the nut housing 50 move backward, the lower end of the rod 60 moves backward, so that the movable cutter 34 moves backward with the bolt 62 as the rotation axis. Figure 5 As a result, the movable cutter 34 is closed relative to the fixed cutter 32, and the upper cutter portion 58 and the lower cutter portion 54 perform the cutting operation. Figure 3 As shown in FIG. 1 , when the nut 48 and the nut housing 50 move forward, the lower end of the rod 60 moves forward, so that the movable cutter 34 moves forward with the bolt 62 as the rotation axis. Figure 3 Thereby, the movable knife 34 is opened relative to the fixed knife 32.

[0056] like Figure 4 As shown, the trigger 28 is rotatably connected to the nut 48 via a pin 64. The trigger 28 also moves in the front-to-back direction as the nut 48 moves in the front-to-back direction. In addition, when the trigger 28 is pulled in by the user, it rotates relative to the nut 48 with the pin 64 as the rotation axis.

[0057] like Figure 3 As shown, the trigger position detection unit 40 includes a magnet 68, a spring 70, and a trigger position sensor 72 (see Figure 4 ). The magnet 68 is arranged to have an N pole on the front side (or rear side) and an S pole on the rear side (or front side). The magnet 68 is supported by the nut housing 50 so as to be movable in the front-rear direction. The spring 70 urges the magnet 68 forward relative to the nut housing 50. The front end of the magnet 68 abuts against the rear surface of the trigger 28. Figure 4 The trigger position sensor 72 shown in the figure includes, for example, a Hall element. The trigger position sensor 72 is fixed to the nut housing 50. The trigger position sensor 72 detects the magnet 68 (see Figure 3 ) is used to detect the retracted position of the trigger 28 relative to the front-rear direction of the nut housing 50.

[0058] Figure 1The control unit 14 shown rotates the electric motor 36 in the forward direction or the reverse direction in response to the detection signal from the trigger position sensor 72. When the trigger 28 is pulled in, the magnet 68 moves to a position behind the neutral position relative to the nut housing 50, and accordingly, the control unit 14 rotates the electric motor 36 in the forward direction. As a result, the movable tool 34 rotates in a direction in which the movable tool 34 is closed relative to the fixed tool 32. On the contrary, when the pulling-in operation of the trigger 28 is released, the magnet 68 moves to a position ahead of the neutral position relative to the nut housing 50, and accordingly, the control unit 14 rotates the electric motor 36 in the reverse direction. As a result, the movable tool 34 rotates in a direction in which the movable tool 34 is opened relative to the fixed tool 32.

[0059] like Figure 6 As shown, a camera 74, a right light 76, and a left light 78 are provided in the housing 24. The camera 74 is provided on the upper surface side of the front portion of the housing 24. The right light 76 is provided on the right surface side of the front portion of the housing 24. The left light 78 is provided on the left surface side of the front portion of the housing 24. The right light 76 and the left light 78 are respectively arranged to face forward, and illuminate the areas near the fixed cutter 32 and the movable cutter 34.

[0060] The camera 74 is arranged to face forward and to capture images of the area near the fixed blade 32 and the movable blade 34. The image data captured by the camera 74 is transmitted to the control unit 14 (see Figure 1 ) is sent. Figure 3 As shown, the optical axis OX of the camera 74 is arranged to face obliquely downward relative to the vertical direction, for example, 12 degrees downward relative to the horizontal direction. The vertical viewing angle θ1 of the camera 74 is, for example, in the range of 45° to 90°, for example, 50°. In this case, the lower cutter section 54 can be brought into the viewing angle of the camera 74 as a whole. Figure 7 As shown, the optical axis OX of the camera 74 is arranged to face forward in the left-right direction. The field of view angle θ2 of the camera 74 in the left-right direction is, for example, in the range of 60° to 120°, for example, 65°. The focal length of the camera 74 is, for example, 50 mm to 100 mm. The resolution of the camera 74 is, for example, QVGA (320×240 pixels) or higher, for example, VGA (640×480 pixels). The frame rate of the camera 74 is, for example, 30 FPS or higher. The shutter speed of the camera 74 is, for example, in the range of 0.1 ms to 2 ms, for example, 1 ms.

[0061] like Figure 7 As shown, the user uses the working machine 2 while holding the handle 26 of the working unit 8 with one hand and wearing a purple glove 80 on the other hand. For example, the user cuts the branch 82 by using the working unit 8 held by one hand while holding the branch 82 with the other hand wearing the glove 80.

[0062] When the working machine 2 is a pruning shears, during normal operation, the green of leaves and the blue of the sky are reflected in the image data of the camera 74, but purple objects are hardly reflected. Therefore, by using the purple gloves 80, it is easier to distinguish the colors reflected during normal operation.

[0063] The color reflected by the camera 74 can be determined based on the hue of each pixel included in the image data when it is expressed in the HSV format using hue (Hue), saturation (Saturation) and brightness (Value). For example, the brown hue of dead leaves, branches, etc. is in the range of 15° to 60°, the green hue of leaves is in the range of 80° to 150°, and the blue hue of the sky is in the range of 180° to 225°. In contrast, the purple hue of the glove 80 is in the range of 270° to 300°. Therefore, based on the hue of the pixel included in the image data, it can be determined whether the pixel corresponds to the glove 80 or to an object other than the glove 80.

[0064] (Approach determination processing)

[0065] When the control unit 14 determines that the glove 80 is close to the fixed blade 32 and the movable blade 34 based on the image data of the camera 74, the control unit 14 causes the working machine 2 to operate in a safer mode than the normal mode. This ensures the safety of the user. Figure 8 The approach determination process performed by the control unit 14 will be described.

[0066] In S2, the control unit 14 acquires image data from the camera 74. The image data is expressed in HSV format, which shows the hue, saturation, and brightness of each pixel included in the image data.

[0067] In S4, the control unit 14 determines whether the camera 74 is blocked based on the image data. Fig. 9 As shown, when the camera 74 is not blocked, the fixed tool 32, the movable tool 34, and the background are reflected in the image data ID. At this time, since the fixed tool 32 does not move relative to the camera 74, the fixed tool 32 is definitely reflected in the pixel P1 configured at the position corresponding to the fixed tool 32. On the other hand, the leaves, branches, etc. in the background are reflected in the pixel P2 configured at the position not corresponding to the fixed tool 32 and the movable tool 34. Therefore, the hue, saturation, and brightness of the pixel P1 and the pixel P2 are different. In contrast, Fig.10As shown in FIG. 1 , when the camera 74 is blocked by an obstacle 84, the fixed blade 32, the movable blade 34, the leaves and branches in the background are not reflected in the image data, and the same obstacle 84 is reflected in almost all pixels. In this case, the pixel P1 arranged at the position corresponding to the fixed blade 32 and the pixel P2 arranged at the position not corresponding to the fixed blade 32 and the movable blade 34 have the same hue, saturation, and brightness. Figure 8 In S4 , the control unit 14 compares the hue, saturation, and brightness of the pixel P1 and the pixel P2 , respectively, and determines that the camera 74 is blocked by the obstacle 84 when the respective differences are within 20%.

[0068] If it is determined in S4 that the camera 74 is blocked (if the answer is yes), the process proceeds to S6. In S6, the control unit 14 stops the working machine 2 abnormally. Specifically, the control unit 14 prohibits the rotation of the electric motor 36, displays the occurrence of the abnormality on the indicator light 20, and emits a warning sound from the buzzer 22 to inform the user that the camera 74 is blocked. After S6, Figure 8 The processing is finished.

[0069] If it is determined in S4 that the camera 74 is not blocked (if the answer is NO), the process proceeds to S8. In S8, the control unit 14 calculates the average value of the brightness of all pixels of the image data.

[0070] In S10, the control unit 14 sets the saturation threshold based on the average value of the brightness calculated in S8. For example, the control unit 14 sets the saturation threshold to a first threshold (e.g., 30%) when the average value of the brightness is greater than a first reference value (e.g., 80%), sets the saturation threshold to a second threshold (e.g., 50%) higher than the first threshold when the average value of the brightness is greater than a second reference value (e.g., 50%) lower than the first reference value, and sets the saturation threshold to a third threshold (e.g., 70%) higher than the second threshold when the average value of the brightness is less than the second reference value.

[0071] In S12 , the control unit 14 selects determination target pixels from pixels included in the image data for which the determination process of S14 to S20 has not yet been executed.

[0072] In S14, the control unit 14 determines whether the hue of the determination target pixel is within a predetermined range (e.g., a range of 230° to 360°, e.g., a range of 235° to 320°). If the hue of the determination target pixel is within the predetermined range (yes), the process proceeds to S16.

[0073] In S16, the control unit 14 determines whether the saturation of the determination target pixel is greater than the saturation threshold value set in S10. When the image data is in HSV format, the hue of a color with low saturation, such as white, gray, and black, may be the same value as the hue of another color with high saturation (for example, purple). Therefore, in this embodiment, when the saturation of the determination target pixel is less than the threshold value, it is determined to be a white, gray, or black pixel instead of a purple pixel corresponding to the glove 80, and when the saturation of the determination target pixel is greater than the threshold value, it is determined to be a purple pixel corresponding to the glove 80.

[0074] In addition, in the image data captured in a bright environment, the saturation of the pixel reflected by the purple glove 80 tends to be low, and in the image data captured in a dark environment, the saturation of the pixel reflected by the purple glove 80 tends to be high. Therefore, in the process of S10 in this embodiment, the higher the average value of the brightness of the pixels included in the image data, the lower the saturation threshold is set, and the lower the average value of the brightness of the pixels included in the image data, the higher the saturation threshold is set. As a result, it is possible to more effectively suppress false detection caused by the reflection of colors with low saturation.

[0075] If the saturation of the determination target pixel is equal to or greater than the saturation threshold value (if YES) in S16, the process proceeds to S18. In S18, the control unit 14 determines that the determination target pixel is a pixel corresponding to the glove 80. After S18, the process proceeds to S22.

[0076] If the hue of the determination target pixel is not within the predetermined range (in the case of No) in S14 and the saturation of the determination target pixel is less than the threshold value (in the case of No) in S16, the process proceeds to S20. In S20, the control unit 14 determines that the determination target pixel is not a pixel corresponding to the glove 80. After S20, the process proceeds to S22.

[0077] In S22, the control unit 14 determines whether the determination process of S14 to S20 for all pixels included in the image data is completed. If the determination process for all pixels is not completed (in the case of No), the process returns to S12. If the determination process for all pixels is completed (in the case of Yes), the process proceeds to S24.

[0078] In S24, the control unit 14 determines the proximity level of the glove 80 relative to the fixed blade 32 and the movable blade 34 based on the number of pixels determined to correspond to the glove 80 among the pixels included in the image data. For example, when the number of all pixels included in the image data is set to N0 and the number of pixels corresponding to the glove 80 is set to N1, the control unit 14 determines the proximity level to be level 0 when the ratio N1 / N0 is less than a first predetermined value (for example, 3%), determines the proximity level to be level 1 when the ratio N1 / N0 is greater than or equal to the first predetermined value (for example, 3%) and less than a second predetermined value (for example, 5%), and determines the proximity level to be level 2 when the ratio N1 / N0 is greater than or equal to the second predetermined value (for example, 5%).

[0079] Alternatively, when a portion including the fixed blade 32 and the movable blade 34 is cut out from the image data as the first partial image data, the number of all pixels included in the first partial image data is set to M0, and the number of pixels corresponding to the glove 80 in the first partial image data is set to M1, the control unit 14 may determine the proximity level to be level 1 when the ratio M1 / M0 is equal to or greater than a predetermined value (e.g., 4%). Alternatively, when a smaller portion including the fixed blade 32 and the movable blade 34 is cut out from the image data as the second partial image data, the number of all pixels included in the second partial image data is set to L0 (L0<M0), and the number of pixels corresponding to the glove 80 in the second partial image data is set to L1, the control unit 14 may determine the proximity level to be level 2 when the ratio L1 / L0 is equal to or greater than a predetermined value (e.g., 4%). Furthermore, when the proximity level does not correspond to either level 1 or level 2, the control unit 14 may determine the proximity level to be level 0.

[0080] In S26, the control unit 14 determines whether the approach level is level 2. If the approach level is level 2 (if the answer is yes), the process proceeds to S28. In S28, the control unit 14 prohibits the rotation of the electric motor 36, displays the occurrence of an abnormality on the display light 20, and emits a warning sound from the buzzer 22 to inform the user that the glove 80 is too close to the fixed blade 32 and the movable blade 34. After S28, Figure 8 The processing is finished.

[0081] When the approach level is not level 2 in S26 (in the case of No), the process enters S30. In S30, the control unit 14 determines whether the approach level is level 1. When the approach level is level 1 (in the case of Yes), the process enters S32. In S32, the control unit 14 displays a warning on the display light 20, and the buzzer 22 emits a warning sound to inform the user that the glove 80 is close to the fixed tool 32 and the movable tool 34. In addition, in S32, the rotation of the electric motor 36 is allowed, and the user can continue to use the working machine 2 to work. After S32, the process returns to S2.

[0082] When the proximity level is not level 1 (in the case of NO) in S30 , that is, when the proximity level is level 0, the process returns to S2 .

[0083] Through the processing of S24-S32, when the approach level is level 0, the operating machine 2 operates as usual. That is, when the approach level is level 0, the operating machine 2 can operate in the normal mode. In addition, when the approach level is level 1, the operating machine 2 operates more safely than in the normal mode. That is, when the approach level is level 1, the operating machine 2 can operate in the first safety mode that is safer than the normal mode. And, when the approach level is level 2, the operating machine 2 operates more safely than in the first safety mode. That is, when the approach level is level 2, the operating machine 2 can operate in the second safety mode that is safer than the first safety mode.

[0084] (Variation Example)

[0085] In the above-mentioned working machine 2, the battery unit 4 and the switch unit 6 may also be mounted on the working unit 8. In this case, a battery mounting portion (not shown) for mounting and dismounting the battery pack 16, a main power switch 18, and a display lamp 20 may also be provided on the outer surface of the housing 24 of the working unit 8. In addition, the control unit 14 and the buzzer 22 may also be accommodated inside the housing 24 of the working unit 8.

[0086] In the above-mentioned working machine 2, the predetermined range of hue may be any range as long as it includes the hue of the color of the object. In addition, the color of the object is not limited to purple, and may be other colors.

[0087] The working machine 2 may also be other types of working machines such as a reciprocating saw or a steel bar bundling machine. For example, when the working machine 2 is a reciprocating saw, a reciprocating saw blade or the like corresponds to the working unit. When the working machine 2 is a steel bar bundling machine, a winding guide that feeds a wire around a steel bar, a hook that twists the wire wound around a steel bar, or the like corresponds to the working unit.

[0088] (Corresponding relationship)

[0089] As described above, in one or more embodiments, the working machine 2 includes: a fixed cutter 32 and a movable cutter 34 (an example of a working unit); an electric motor 36 (an example of a prime mover) that drives the movable cutter 34; a camera 74 (an example of a camera unit) that captures images of the vicinity of the fixed cutter 32 and the movable cutter 34; and a control unit 14. The working machine 2 can operate in a normal mode in which the working machine 2 operates as usual and in a safe mode in which the working machine 2 operates more safely than in the normal mode. The control unit 14 is configured to cause the working machine 2 to operate in the safe mode when it is determined that the glove 80 (an example of an object) is close to the fixed cutter 32 and the movable cutter 34 based on the number of pixels whose hue when expressed in HSV format is within a predetermined range among the pixels included in the image data captured by the camera 74.

[0090] When the image data captured by the camera 74 is expressed in HSV format, objects of the same color have the same hue even if the brightness at the time of capturing the image is different. Therefore, according to the above configuration, even when the working machine 2 is used outdoors, the approach of the glove 80 to the fixed blade 32 and the movable blade 34 can be detected with high accuracy based on the image data captured by the camera 74.

[0091] In one or more embodiments, the control unit 14 is configured to determine whether the glove 80 is close to the fixed tool 32 and the movable tool 34 based on the number of pixels whose hue is within a predetermined range and whose saturation is above a threshold when expressed in HSV format, among the pixels contained in the image data captured by the camera 74.

[0092] When the image data captured by the camera 74 is expressed in HSV format, the hue of a color with low saturation, such as white, black, and gray, may have the same value as the hue of another color with high saturation (e.g., purple). Therefore, when determining whether a pixel corresponds to the glove 80 based only on the hue of the pixel, a pixel with a color with low saturation may be mistakenly determined as a pixel corresponding to the glove 80. According to the above configuration, since it is determined whether the glove 80 is close to the fixed blade 32 and the movable blade 34 based on the number of pixels whose hue is within a predetermined range and whose saturation is greater than a threshold value, it is possible to suppress erroneous detection caused by the reflection of a color with low saturation.

[0093] In one or more embodiments, the control unit 14 sets the saturation threshold to a lower value as the brightness of pixels included in the image data captured by the camera 74 expressed in HSV format increases.

[0094] Generally speaking, when the image data is captured in a bright environment, the saturation of the pixel corresponding to the purple glove 80 tends to be low, and when the image data is captured in a dark environment, the saturation of the pixel corresponding to the purple glove 80 tends to be high. According to the above configuration, since the saturation threshold is set to a lower value as the brightness of the pixel included in the image data is higher, it is possible to more reliably detect the approach of the glove 80 to the fixed blade 32 and the movable blade 34.

[0095] In one or more embodiments, the predetermined range of hue may be a range of 230° to 360°.

[0096] When the working machine 2 is used outdoors, the blue of the sky, the green of leaves and grass, and the brown of branches and trunks may be reflected in the image data captured by the camera 74. The hues of these colors are within the range of 0° to 230°, and colors (such as purple) within the range of 230° to 360° are hardly reflected in the image data. According to the above configuration, by setting the hue of the color of the glove 80 within the range of 230° to 360°, it is possible to detect with high accuracy the situation where the glove 80 approaches the fixed blade 32 and the movable blade 34.

[0097] In one or more embodiments, the working machine 2 further includes a housing 24 that supports the fixed cutter 32 and the movable cutter 34, and the camera 74, and is held by the user. The movable cutter 34 is rotatable relative to the fixed cutter 32 about a rotation axis extending in the left-right direction and is driven by an electric motor 36.

[0098] The above-mentioned working machine 2 functions as a pruning shear for cutting branches 82 and the like. When using the above-mentioned working machine 2 to cut branches 82, the user sometimes performs the work while holding the housing 24 with one hand and holding the branch 82 with the other hand. According to the above-mentioned configuration, by wearing the glove 80 of a color (e.g., purple) within a predetermined range on the other hand, the working machine 2 can be operated in a safe mode when the glove 80 approaches the fixed blade 32 and the movable blade 34. The safety of the user can be ensured.

[0099] In one or more embodiments, the camera 74 is disposed on the upper surface side of the housing 24 .

[0100] In the structure in which the working machine 2 is provided with the fixed cutter 32 and the movable cutter 34, if the camera 74 is located on the right surface side (or the left surface side) of the housing 24, although the area on the right side (or the left side) of the fixed cutter 32 and the movable cutter 34 enters the field of view of the camera 74, the area on the left side (or the right side) of the fixed cutter 32 and the movable cutter 34 is blocked by the fixed cutter 32 and the movable cutter 34 and does not enter the field of view of the camera 74, so it is difficult to photograph the areas on the left and right sides of the fixed cutter 32 and the movable cutter 34. In addition, if the camera 74 is located on the lower surface side of the housing 24, although the areas on the left and right sides of the fixed cutter 32 and the movable cutter 34 can be photographed, the camera 74 will protrude downward from the housing 24 and easily interfere with the operation. According to the above-mentioned structure, since the camera 74 is arranged on the upper surface side of the housing 24, the areas on the left and right sides of the fixed cutter 32 and the movable cutter 34 can be photographed. In addition, it is possible to suppress the situation in which the camera 74 protrudes downward from the housing 24 and interferes with the operation.

[0101] In one or more embodiments, when the movable blade 34 is maximally opened relative to the fixed blade 32, the camera 74 is arranged below the upper end of the movable blade 34 when the longitudinal direction of the housing 24 is set to the horizontal direction.

[0102] Even if the camera 74 is disposed on the upper surface side of the housing 24 and the camera 74 protrudes upward from the housing 24, if the camera 74 is disposed at a position lower than the upper end of the movable cutter 34 when the movable cutter 34 is in the most open state, it is not easy to interfere with the operation. According to the above-mentioned structure, even if the camera 74 protrudes upward from the housing 24, it is possible to suppress the situation where the camera 74 interferes with the operation.

[0103] In one or more embodiments, a right lamp 76 and a left lamp 78 (an example of a lighting unit) are further provided. The right lamp 76 and the left lamp 78 are supported by the housing 24 and illuminate the area near the fixed blade 32 and the movable blade 34 .

[0104] According to the above configuration, even in a dark environment, image data can be captured in a state where the areas near the fixed cutter 32 and the movable cutter 34 are illuminated by the right lamp 76 and the left lamp 78, so that image data can be acquired under the same conditions as when image data is captured in a bright environment. Deviations in detection accuracy caused by differences in ambient brightness can be suppressed.

[0105] In one or more embodiments, the right lamp 76 (an example of a right lighting unit) is arranged on the right surface side of the housing 24 , and the left lamp 78 (an example of a left lighting unit) is arranged on the left surface side of the housing 24 .

[0106] In the structure in which the working machine 2 includes the fixed cutter 32 and the movable cutter 34, if the working machine 2 includes only the right light 76 (or the left light 78), although the area on the right side (or the left side) of the fixed cutter 32 and the movable cutter 34 is illuminated, the area on the left side (or the right side) of the fixed cutter 32 and the movable cutter 34 is blocked by the fixed cutter 32 and the movable cutter 34 and is not illuminated, so it is difficult to illuminate the area on the left and right sides of the fixed cutter 32 and the movable cutter 34. According to the above structure, since the working machine 2 includes both the right light 76 and the left light 78, the area on the left and right sides of the fixed cutter 32 and the movable cutter 34 can be appropriately illuminated.

[0107] In one or more embodiments, the control unit 14 respectively determines, among the pixels included in the image data, a pixel P1 (an example of the first pixel) arranged at a position corresponding to the fixed tool 32 and a pixel P2 (an example of the second pixel) arranged at a position not corresponding to the fixed tool 32 and the movable tool 34, and determines whether the camera 74 is blocked by the obstacle 84 based on the hue, saturation and / or brightness of the pixel P1 and the pixel P2 when expressed in HSV form.

[0108] When the camera 74 is not blocked by the obstacle 84, the pixel P1 at the position corresponding to the fixed tool 32 is always reflected in the same color (i.e., the color of the fixed tool 32), and the pixel P2 at the position not corresponding to the fixed tool 32 or the movable tool 34 is reflected in the color of the background. In this case, the hue, saturation, and brightness of the pixel P1 and the pixel P2 are different values. In contrast, when the camera 74 is blocked by the obstacle 84, the color of the same obstacle 84 is reflected in both the pixel P1 at the position corresponding to the fixed tool 32 and the pixel P2 at the position not corresponding to the fixed tool 32 or the movable tool 34. In this case, the hue, saturation, and brightness of the pixel P1 and the pixel P2 are approximately the same value. According to the above configuration, it is possible to appropriately determine whether the camera 74 is blocked by the obstacle 84 based on the hue, saturation and / or brightness of the pixel P1 configured at the position corresponding to the fixed tool 32 and the pixel P2 configured at the position not corresponding to the fixed tool 32 or the movable tool 34.

[0109] In one or more embodiments, the camera 74 has a left-right field of view in the range of 60° to 120°.

[0110] If the field of view angle in the left-right direction is too wide, the glove 80 will be reflected in the image data even if the glove 80 is not that close to the fixed blade 32 and the movable blade 34 in the left-right direction. On the contrary, if the field of view angle in the left-right direction is too narrow, the glove 80 will not be reflected in the image data until the glove 80 is very close to the fixed blade 32 and the movable blade 34 in the left-right direction. According to the above configuration, whether the glove 80 is close to the fixed blade 32 and the movable blade 34 in the left-right direction can be appropriately detected.

[0111] In one or more embodiments, the vertical field angle of the camera 74 is in the range of 45° to 90°.

[0112] If the vertical viewing angle is too wide, the glove 80 will be reflected in the image data even if the glove 80 is not that close to the fixed blade 32 and the movable blade 34 in the vertical direction. On the contrary, if the vertical viewing angle is too narrow, the glove 80 will not be reflected in the image data until the glove 80 is very close to the fixed blade 32 and the movable blade 34 in the vertical direction. According to the above configuration, it is possible to appropriately detect whether the glove 80 is close to the fixed blade 32 and the movable blade 34 in the vertical direction.

[0113] In one or more embodiments, the shutter speed of the camera 74 is in the range of 0.1 ms to 2 ms.

[0114] According to the above-described configuration, when the working machine 2 is used outdoors, image data can be captured with appropriate brightness.

[0115] In one or more embodiments, the safety mode includes a first safety mode for operating more safely than the normal mode and a second safety mode for operating more safely than the first safety mode. The control unit 14 is configured to operate the working machine 2 in the first safety mode when it is determined that the glove 80 approaches the fixed tool 32 and the movable tool 34 at a proximity level of level 1 (an example of the first proximity level) based on the number of pixels whose hues are within a predetermined range among the pixels included in the image data captured by the camera 74. The control unit 14 is configured to operate the working machine 2 in the second safety mode when it is determined that the glove 80 approaches the fixed tool 32 and the movable tool 34 at a proximity level of level 2 (an example of the second proximity level) that is closer than level 1 based on the number of pixels whose hues are within a predetermined range among the pixels included in the image data captured by the camera 74.

[0116] According to the above-described configuration, the working machine 2 can be operated in a safer mode in stages according to the level of approach of the glove 80 to the fixed blade 32 and the movable blade 34 .

Claims

1. A working machine, wherein: The operating machine has: Operations Department; A prime mover that drives the working unit; a camera unit configured to capture an image of a vicinity of the working unit; and Control Department, The working machine can operate in a normal mode in which the working machine operates normally and in a safe mode in which the working machine operates more safely than in the normal mode. The control unit is configured to operate the working machine in the safety mode when it is determined that an object is approaching the working unit based on the number of pixels whose hues when expressed in HSV format are within a predetermined range among pixels included in the image data captured by the camera unit.

2. The working machine according to claim 1, wherein: The control unit is configured to determine whether the object is close to the working unit based on the number of pixels whose hue is within the predetermined range and whose saturation is greater than a threshold value when expressed in HSV format, among pixels included in the image data captured by the camera unit.

3. The working machine according to claim 2, wherein: The control unit sets the threshold value to a lower value as the brightness of pixels included in the image data captured by the imaging unit when expressed in HSV format is higher.

4. The working machine according to any one of claims 1 to 3, wherein: The predetermined range is a range of 230° to 360°.

5. The working machine according to any one of claims 1 to 4, wherein: The working machine further includes a housing that supports the working unit and the imaging unit and is held by a user. The working unit includes a fixed cutter and a movable cutter. The movable cutter is rotatable relative to the fixed cutter about a rotation axis extending in the left-right direction and is driven by the prime mover.

6. The working machine according to claim 5, wherein: The imaging unit is disposed on the upper surface side of the housing.

7. The working machine according to claim 6, wherein: When the movable blade is maximally opened relative to the fixed blade, the imaging unit is arranged below an upper end of the movable blade when the longitudinal direction of the housing is horizontal.

8. The working machine according to any one of claims 5 to 7, wherein: The working machine further includes a lighting unit that is supported by the housing and illuminates an area near the working unit.

9. The working machine according to claim 8, wherein: The lighting unit includes a right lighting unit disposed on the right surface side of the housing and a left lighting unit disposed on the left surface side of the housing.

10. The working machine according to any one of claims 5 to 9, wherein: The control unit respectively determines the first pixel arranged at a position corresponding to the fixed tool and the second pixel arranged at a position not corresponding to the fixed tool and the movable tool among the pixels contained in the image data, and judges whether the camera unit is blocked by an obstacle based on the hue, saturation and / or brightness of the first pixel and the second pixel when expressed in HSV form.

11. The working machine according to any one of claims 5 to 10, wherein: The viewing angle of the camera unit in the left-right direction is within a range of 60° to 120°.

12. The working machine according to any one of claims 5 to 11, wherein: The vertical viewing angle of the camera unit is within a range of 45° to 90°.

13. The working machine according to any one of claims 5 to 12, wherein: The shutter speed of the camera unit is in the range of 0.1 ms to 2 ms.

14. The working machine according to any one of claims 1 to 13, wherein: The safety mode includes a first safety mode that operates more safely than the normal mode and a second safety mode that operates more safely than the first safety mode. The control unit is configured to cause the working machine to operate in the first safety mode when it is determined that the object is approaching the working unit at a first approach level based on the number of pixels whose hue is within the predetermined range among the pixels included in the image data captured by the camera unit, The control unit is configured to operate the working machine in the second safety mode when it is judged that the object is approaching the working unit at a second proximity level that is closer than the first proximity level based on the number of pixels whose hue is within the predetermined range among the pixels included in the image data captured by the camera unit.

Images