Work assisting system

Abstract

To provide a work assisting system capable of accurately detecting an offset boom angle.　An offset boom angle detection device 14 includes a first detection part S1 and a second detection part S2. The second detection part S2 includes an angular velocity sensor that detects an offset boom angle on the basis of an angular velocity change. The first detection part S1 includes a magnetic flux sensor unit 141 and a magnet unit 142 attached to an offset boom mechanism 41 so as to relatively rotatably move in accordance with a change in the offset boom angle. The magnetic flux sensor unit 141 is disposed so as to face the magnet unit 142 in a non-contact state, and detects a change in magnetic flux density associated with rotational movement. A portable terminal 13 identifies the offset boom angle on the basis of detection values from the first detection part S1 and the second detection part S2.

Description

Work Support System

[0001] The present disclosure relates to a work assistance system.

[0002] Work machines (e.g., ICT construction machines) incorporating work support systems (e.g., machine guidance functions) have been proposed. This type of work machine has sensors located on movable parts, and the position of a work reference point (e.g., bucket tip position) is detected by processing the detection results of the sensors. For example, the work machine shown in Patent Document 1 has an IMU (INERTIAL MEASUREMENT UNIT) sensor, which includes an angular velocity sensor, an acceleration sensor, etc., located on a movable part (boom, arm, bucket, etc.). In addition, in the case of a work machine equipped with an offset boom mechanism, a sensor for detecting the offset boom angle of the offset boom mechanism is also required.

[0003] Japanese Patent Application Laid-Open No. 2022-101440

[0004] However, when an IMU sensor is used to detect the offset boom angle, drift errors accumulate, making it difficult to accurately detect the offset boom angle. It has also been proposed to detect the offset boom angle using an angle sensor (such as a potentiometer or rotary encoder) that does not generate drift errors. However, conventional angle sensors must be installed across moving parts that rotate relative to one another, which not only makes them difficult to install but also makes them susceptible to damage from loads caused by misalignment.

[0005] Therefore, an object of the present disclosure is to provide a work support system that can accurately detect the offset boom angle.

[0006] In one aspect, the present invention provides the following solution: A work assistance system comprising: a detection device installed on a movable part of a work machine and acquiring attitude information of the movable part; and a work assistance device that provides operation assistance information for the work machine based on the attitude information acquired from the detection device, wherein the work machine is equipped with an offset boom mechanism that offsets a boom in the left-right direction, the detection device includes an offset boom angle detection device that detects the offset boom angle of the offset boom mechanism, the offset boom angle detection device comprises a first detection unit and a second detection unit, the second detection unit comprises an angular velocity sensor that detects the offset boom angle based on a change in angular velocity, the first detection unit comprises a magnetic flux sensor unit and a magnet unit attached to the offset boom mechanism so as to rotate relatively in response to changes in the offset boom angle, the magnetic flux sensor unit is disposed opposite the magnet unit in a non-contact state and detects changes in magnetic flux density accompanying the rotational movement, and the work assistance device identifies the offset boom angle based on detection values ​​of the first detection unit and the second detection unit.

[0007] According to the present disclosure, it is possible to provide a work support system that can detect the offset boom angle with high accuracy.

[0008] 6 is a schematic side view of a work machine incorporating a work assistance system. FIG. 7 is a block diagram showing the configuration of the work assistance system. FIG. 8 is a perspective view of a detection device. FIG. 9 is a diagram showing components of an offset boom angle detection device, where (a) is a perspective view of a magnetic flux sensor unit, (b) is a perspective view of a magnet unit, (c) is a perspective view of a transmitter unit, and (d) is a perspective view of a spacer. FIG. 10 is a side view of a main part of a work machine showing the installation state of an offset boom angle detection device. FIG. 11 is a bottom view of a main part of a work machine showing the installation state of an offset boom angle detection device (installation state with rotational axes aligned), where (a) is a diagram showing a left offset state, (b) is a diagram showing a state without offset, and (c) is a diagram showing a right offset state. FIG. 12 is a diagram showing the relationship (linking information) between the output value of the magnetic flux sensor and the output value of the IMU sensor shown in FIG. 11. FIG. 13 is a bottom view of a main part of a work machine showing the installation state of an offset boom angle detection device (installation state with rotational axes misaligned), where (a) is a diagram showing a left offset state, (b) is a diagram showing a state without offset, and (c) is a diagram showing a right offset state. 9 is a diagram showing the relationship (linking information) between the output value of the magnetic flux sensor and the output value of the IMU sensor shown in FIG. 8 .

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0010] 1 is a hydraulic excavator 2 incorporating a work assistance system 1. The work assistance system 1 uses, for example, a machine guidance function to assist the work of an operator operating the hydraulic excavator 2. Work machines to which the work assistance system 1 can be applied are not limited to excavators such as the hydraulic excavator 2, but may also be loading and unloading machines such as cranes.

[0011] As shown in FIG. 1 , the hydraulic excavator 2 includes an operating unit 3 , a work implement 4 , a support body 5 , and a traveling device 6 .

[0012] The work machine 4 is configured by sequentially connecting an offset boom mechanism 41, an arm 42, and a bucket 43, and is operated by an operator. The offset boom mechanism 41 is connected to the front end of the support body 5 via a boom pin 41a so as to be able to swing up and down, and swings in response to the hydraulic extension and contraction action of a boom cylinder C1 provided between the support body 5 and the offset boom mechanism 41. The arm 42 is connected to the tip of the offset boom mechanism 41 via an arm pin 42a so as to be able to swing back and forth and up and down, and swings in response to the hydraulic extension and contraction action of an arm cylinder C2 provided between the offset boom mechanism 41 and the arm 42. The bucket 43 is connected to the tip of the arm 42 via a bucket pin (attachment pin) 43a so as to be able to swing back and forth and up and down, and swings in response to the hydraulic extension and contraction action of a bucket cylinder C3 provided between the arm 42 and the bucket 43.

[0013] The bucket 43 is a type of attachment that is detachably mounted on the tip of the arm 42 and can be replaced with another attachment depending on the type of work. Examples of attachments include a grapple for gripping wood, a breaker for crushing concrete blocks, and a skeleton bucket for sieving. The work support system 1 is not limited to excavation work using the bucket 43, but can also be applied to work using other attachments.

[0014] The offset boom mechanism 41 includes a first boom 411, a second boom 412, a third boom 413, and a link member (not shown). The first boom 411 is supported on the support body 5 via a boom pin 41a so as to be able to swing up and down. The second boom 412 is supported at the tip of the first boom 411 via a first offset pin (not shown) so as to be able to swing left and right. The third boom 413 is supported at the tip of the second boom 412 via a second offset pin 413a (see FIGS. 6 and 8) so as to be able to swing left and right, and supports the arm 42 via an arm pin 42a so as to be able to swing back and forth and up and down. The link member is disposed parallel to the second boom 412 and is supported by the first boom 411 and the third boom 413 so as to be able to swing left and right.

[0015] The first boom 411, second boom 412, third boom 413 and link member constitute a parallel link mechanism that offsets (translates) the third boom 413, arm 42 and bucket 43 left and right in response to the left and right swing of the second boom 412. The offset boom mechanism 41 also includes an offset cylinder (not shown) between the first boom 411 and second boom 412, and is offset left and right in response to the hydraulic extension and retraction of the offset cylinder.

[0016] The operation unit 3 is a riding space for an operator who operates the hydraulic excavator 2. The support body 5 supports the operation unit 3 and the work machine 4. The traveling device 6 supports the support body 5 so that it can turn and travel. The traveling device 6 is not limited to a crawler type having crawlers 61 as shown in FIG. 1 , but may also be a wheel type having wheels (not shown).

[0017] [Work Support System] As shown in FIGS. 1 and 2 , the work support system 1 includes detection devices 11A, 11B, and 11C, an offset boom angle detection device 14, a collection device 12, and a mobile terminal 13.

[0018] As shown in Fig. 1, the detection devices 11A, 11B, and 11C are respectively installed on the offset boom mechanism 41, the arm 42, and the bucket 43. As shown in Fig. 2 and Fig. 3, the detection devices 11A, 11B, and 11C each include a posture sensor 111, a wireless communication unit 112, a control unit 113, a battery 114, a case 115, and a magnetic member 116.

[0019] The attitude sensor 111 detects the attitude of the installation location. For example, an IMU (INERTIAL MEASUREMENT UNIT) sensor that detects three-dimensional acceleration and angular velocity is used as the attitude sensor 111.

[0020] The wireless communication unit 112 performs wireless communication with the collection device 12. For example, the wireless communication unit 112 uses BLUETOOTH (registered trademark) as its wireless communication method.

[0021] The control unit 113 acquires the posture information from the posture sensor 111 and transmits the acquired posture information to the collection device 12 via the wireless communication unit 112 .

[0022] The battery 114 supplies power to the attitude sensor 111, the wireless communication unit 112, and the control unit 113. With these detection devices 11A, 11B, 11C, it is possible to easily install them in a desired location without having to take the trouble of running a power supply cable or a data communication cable to the work machine 4. As a result, the work assistance system 1 of this embodiment can easily add machine guidance functions to an existing work machine or update the machine guidance functions.

[0023] The case 115 houses the attitude sensor 111, the wireless communication unit 112, the control unit 113, and the battery 114. The battery 114 may be housed in a case separate from the case 115, and may supply power to the detection devices 11A, 11B, and 11C via a cable.

[0024] The magnetic member 116 is, for example, a permanent magnet, and its magnetic force secures the detectors 11A, 11B, and 11C to the offset boom mechanism 41, arm 42, and bucket 43, each of which is made of metal. For example, as shown in FIG. 3 , the magnetic member 116 is provided on the bottom of the case 115, and its magnetic force secures the bottom of the case 115 to the offset boom mechanism 41, arm 42, and bucket 43, respectively. Such detectors 11A, 11B, and 11C can be more easily installed at desired locations.

[0025] The offset boom angle detection device 14 is installed in the offset boom mechanism 41, detects the offset boom angle of the offset boom mechanism 41 (the left and right swing angle of the second boom 412), and wirelessly transmits the detected information to the collection device 12. Details of the offset boom angle detection device 14 will be described later.

[0026] 1, the collecting device 12 is installed on the support 5. For example, the collecting device 12 can be easily installed on the floor of the operation unit 3. As shown in FIG. 2, the collecting device 12 includes a posture sensor 121, a wireless communication unit 122, and a control unit 123.

[0027] The attitude sensor 121 detects the attitude of the support body 5. For example, the attitude sensor 121 is an IMU sensor that detects three-dimensional acceleration and angular velocity.

[0028] The wireless communication unit 122 performs wireless communication with the detection devices 11A, 11B, and 11C, the offset boom angle detection device 14, and the mobile terminal 13. For example, the wireless communication unit 122 uses BLUETOOTH (registered trademark) as its wireless communication method.

[0029] The control unit 123 transmits the attitude information of the work implement 4 collected from the detection devices 11A, 11B, and 11C and the offset boom angle detection device 14, and the attitude information of the support body 5 detected by the attitude sensor 121, to the mobile terminal 13 via the wireless communication unit 122. For example, when the control unit 123 of this embodiment receives a request signal for attitude information from the mobile terminal 13, it collects the attitude information of the work implement 4 detected by the detection devices 11A, 11B, and 11C and the offset boom angle detection device 14. The control unit 123 then transmits the attitude information of the work implement 4 collected from the detection devices 11A, 11B, and 11C and the offset boom angle detection device 14, and the attitude information of the support body 5 detected by its own attitude sensor 121, to the mobile terminal 13.

[0030] The collection device 12 operates on power (for example, a cigarette lighter socket) supplied from the hydraulic excavator 2. The collection device 12 may have a built-in battery and operate on power supplied from the battery.

[0031] The mobile terminal 13 is a smartphone or tablet terminal that is a computer with a communication function, and as shown in FIG. 2, the mobile terminal 13 includes an imaging unit 131, a wireless communication unit 132, a display unit 133, and a control unit 134.

[0032] The imaging unit 131 captures still images and videos. In this embodiment, it is used to capture a side image of the hydraulic excavator 2. The side image is an image of a feature point of the hydraulic excavator 2, and is used to register the coordinates of the feature points.

[0033] The wireless communication unit 132 performs wireless communication at least with the collection device 12. For example, the wireless communication unit 132 uses BLUETOOTH (registered trademark) as its wireless communication method.

[0034] The display unit 133 is configured as a touch screen having a display function and a touch input function, and is used to display operation support information, etc.

[0035] The control unit 134 includes, as hardware, an arithmetic unit, a main memory device, and an auxiliary memory device (not shown). The arithmetic unit is a central processing unit (CPU) or the like, and executes programs stored in the main memory device and the auxiliary memory device. The main memory device is a read-only memory (ROM) or a random access memory (RAM). The main memory device stores programs and data such as an operating system (OS), which is basic software, and application software. The auxiliary memory device is a hard disk drive (HDD) or a solid state drive (SSD), and stores application software and related data.

[0036] The control unit 134 executes a work support program (dedicated app) to cause the mobile terminal 13 to operate as a work support device. The mobile terminal 13 operating as a work support device provides operation support information for the hydraulic excavator 2 based on a plurality of pieces of attitude information acquired from the detection devices 11A, 11B, and 11C, the offset boom angle detection device 14, and the collection device 12. For example, the mobile terminal 13 in this embodiment calculates the distance between the tip position (work reference point) of the bucket 43 and the target construction surface based on the plurality of pieces of attitude information received from the collection device 12, and displays the calculated distance on the display unit 133.

[0037] [Offset Boom Angle Detecting Device] Next, the offset boom angle detecting device 14 will be described with reference to FIGS. 2 and 4 to 9. FIG.

[0038] The offset boom angle detection device 14 includes a first detection section S1, a second detection section S2, and a transmission unit U.

[0039] The first detection section S1 includes a magnetic flux sensor unit 141 and a magnet unit 142 attached to the offset boom mechanism 41 so as to rotate relative to each other in response to changes in the offset boom angle. The magnet unit 142 includes a permanent magnet and generates a magnetic field around it. The magnetic flux sensor unit 141 includes a magnetic detection element (e.g., a Hall IC) that detects the magnetic field (magnetic flux density) and outputs changes in the magnetic field as changes in voltage.

[0040] The magnetic flux sensor unit 141 is disposed so as to face the magnet unit 142 in a non-contact state, and detects changes in the magnetic field that accompany relative rotational movement with respect to the magnet unit 142. This makes it possible to detect the offset boom angle of the offset boom mechanism 41 based on the output voltage of the magnetic flux sensor unit 141.

[0041] Unlike an IMU sensor, this type of first detection unit S1 does not accumulate drift errors, making it possible to accurately detect the offset boom angle. Furthermore, unlike angle sensors such as potentiometers and rotary encoders, the first detection unit S1 does not need to be installed across moving parts that rotate relative to one another, making installation easier and eliminating the risk of damage from loads caused by misalignment.

[0042] The offset boom angle to be detected by the offset boom angle detection device 14 is the relative left / right swing angle between the first boom 411 and the second boom 412, or the relative left / right swing angle between the second boom 412 and the third boom 413.

[0043] The magnetic flux sensor unit 141 is attached to any one of the first boom 411 , the second boom 412 and the third boom 413 .

[0044] When the magnetic flux sensor unit 141 is attached to the tip side of the first boom 411, the magnet unit 142 is attached to the base end side of the second boom 412 so as to face the magnetic flux sensor unit 141 in a non-contact state.

[0045] Furthermore, when the magnetic flux sensor unit 141 is attached to the base end side of the second boom 412, the magnet unit 142 is attached to the tip side of the first boom 411 so as to face the magnetic flux sensor unit 141 in a non-contact state.

[0046] Furthermore, when the magnetic flux sensor unit 141 is attached to the tip side of the second boom 412, the magnet unit 142 is attached to the base end side of the third boom 413 so as to face the magnetic flux sensor unit 141 in a non-contact state.

[0047] Furthermore, when the magnetic flux sensor unit 141 is attached to the base end side of the third boom 413, the magnet unit 142 is attached to the tip side of the second boom 412 so as to face the magnetic flux sensor unit 141 in a non-contact manner. Hereinafter, the first detection unit S1 will be described in more detail with reference to Figures 5 and 6 which show this attachment example.

[0048] The magnetic flux sensor unit 141 and the magnet unit 142 are attached to the offset boom mechanism 41 via attachment stays 143 and 144, respectively.

[0049] In the installation example shown in Figures 5 and 6, the appropriate position for the magnetic flux sensor unit 141 is on the rotation axis of the second offset pin 413a. Therefore, the mounting stay 143 includes multiple fixing portions 143a, a stay main body 143b, and an attachment portion 143c. The multiple fixing portions 143a are fixed to the underside of the third boom 413. The stay main body 143b has a generally inverted U shape and is connected to the multiple fixing portions 143a so as to straddle the end faces of the second offset pins 413a. The attachment portion 143c extends from the center of the stay main body 143b in the direction of the rotation axis of the second offset pin 413a, and the magnetic flux sensor unit 141 is attached to the attachment portion 143c. This allows the magnetic flux sensor unit 141 to be installed in the appropriate position.

[0050] In the installation example shown in Figures 5 and 6, the appropriate position for the magnet unit 142 is a position along the rotation axis of the second offset pin 413a, facing the magnetic flux sensor unit 141 without contact. Therefore, the mounting stay 144 includes multiple fixing portions 144a, a stay main body 144b, and an attachment portion 144c. The multiple fixing portions 144a are fixed to the underside of the second boom 412. The stay main body 144b has a generally inverted L shape extending from the multiple fixing portions 144a toward the rotation axis of the second offset pin 413a. The attachment portion 144c extends from the tip of the stay main body 144b in the direction of the rotation axis of the second offset pin 413a, and the magnet unit 142 is attached to the attachment portion 144c. This allows the magnet unit 142 to be attached in the appropriate position.

[0051] The fixing portions 143a, 144a of the mounting stays 143, 144 preferably include magnetically attached portions 143d, 144d. The magnetically attached portions 143d, 144d are, for example, permanent magnets, and are fixed to the third boom 413 and the second boom 412, which are made of metal, by their magnetic force. Such mounting stays 143, 144 allow the magnetic flux sensor unit 141 and the magnet unit 142 to be easily installed in appropriate positions. Furthermore, when installing the magnetic flux sensor unit 141 and the magnet unit 142, an appropriate distance can be ensured between the magnetic flux sensor unit 141 and the magnet unit 142 by inserting a spacer SP shown in FIG. 4 between the magnetic flux sensor unit 141 and the magnet unit 142. The spacer SP is removed after installation.

[0052] The second detection unit S2 includes an angular velocity sensor that detects the offset boom angle of the offset boom mechanism 41 based on changes in angular velocity. For example, the second detection unit S2 is an IMU sensor including an angular velocity sensor, and is installed on the side of the second boom 412. Although such a second detection unit S2 may accumulate drift errors, it has the advantage of being able to directly obtain the angle value of the second boom 412, rather than a voltage value as with the first detection unit S1.

[0053] The transmitting unit U is configured with a wireless communication unit 145, a control unit 146, a battery 147, a case 148, a second detection unit S2, and a magnetic unit (not shown), and is installed, for example, on the side of the second boom 412.

[0054] The wireless communication unit 145 performs wireless communication with the collection device 12. For example, the wireless communication unit 145 uses BLUETOOTH (registered trademark) as its wireless communication method.

[0055] The control unit 146 acquires a voltage value from the magnetic flux sensor unit 141 via the cable C and an angle value from the second detection unit S2, and transmits these acquired values ​​to the collection device 12 via the wireless communication unit 145.

[0056] The battery 147 supplies power to the first detector S1 , the second detector S2 , the wireless communication unit 145 , and the control unit 146 .

[0057] The case 148 houses the wireless communication unit 145, the control unit 146, and the battery 147. In this embodiment, the case 148 also houses the second detection unit S2, which allows the transmission unit U and the second detection unit S2 to be integrated, thereby reducing the number of parts and costs.

[0058] The magnetically attracted portion is, for example, a permanent magnet, and is fixed by its magnetic force to the metal second boom 412 or to a metal plate P provided on the second boom 412. Such a transmitting unit U can be easily installed in the offset boom mechanism 41.

[0059] [Process for Determining Offset Boom Angle] The portable terminal 13 determines the offset boom angle of the offset boom mechanism 41 based on the detection values ​​of the first detection unit S1 and the second detection unit S2. For example, the portable terminal 13 creates linking information (see FIGS. 7 and 9 ) that links the detection value (voltage) of the first detection unit S1 to the offset boom angle detected by the second detection unit S2, and thereafter determines the offset boom angle based on the detection value of the first detection unit S1 and the linking information. In other words, the output value of the second detection unit S2, in which drift error accumulates, is used only when creating the linking information. Thereafter, the offset boom angle is determined based on the detection value of the first detection unit S1 and the linking information, so an accurate offset boom angle without accumulated error can be obtained.

[0060] When creating the linking information, the mobile terminal 13 requests the operator to perform an offset operation of the offset boom mechanism 41, and creates the linking information based on the detection values ​​of the first detection unit S1 and the second detection unit S2 obtained during the offset operation associated with this offset operation. For example, the mobile terminal 13 first displays an offset operation request (e.g., "Initial settings for the offset boom sensor will be performed. Please operate the offset boom from the left offset position to the right offset position.") on the display unit 133 and waits for the operator's operation. When the offset operation begins in response to the operator's operation, the mobile terminal 13 continuously obtains the detection values ​​of the first detection unit S1 and the second detection unit S2 and creates the linking information as shown in FIGS. 7 and 9 .

[0061] When the first detection unit S1 is aligned with the rotation axis of the second offset pin 413a as shown in FIG. 6, the figure representing the linking information is a straight line as shown in FIG. 7. When the first detection unit S1 is offset from the rotation axis of the second offset pin 413a as shown in FIG. 8, the figure representing the linking information is a curved line as shown in FIG. 9. In either case, after the linking information is created, an accurate offset boom angle can be obtained based on the detection value of the first detection unit S1 and the linking information. This reduces the installation accuracy requirements for the magnetic flux sensor unit 141 and the magnet unit 142, making it possible to easily install the magnetic flux sensor unit 141 and the magnet unit 142.

[0062] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments.

[0063] REFERENCE SIGNS LIST 1 Work support system 2 Hydraulic excavator (work machine) 3 Operation unit 4 Work machine 41 Offset boom mechanism 411 First boom 412 Second boom 413 Third boom 42 Arm 43 Bucket 5 Support body 6 Traveling device 11A to 11C Detection device 12 Collection device 13 Portable terminal (work support device) 14 Offset boom angle detection device 141 Magnetic flux sensor unit 142 Magnet unit 143, 144 Mounting stay 143d, 144d Magnetically attached portion S1 First detection unit S2 Second detection unit U Transmission unit

Claims

1. A work support system comprising: a detection device installed on a movable part of a work machine and acquiring attitude information of the movable part; and a work support device that provides operation support information for the work machine based on the attitude information acquired from the detection device, wherein the work machine is equipped with an offset boom mechanism that offsets a boom in the left and right direction, the detection device includes an offset boom angle detection device that detects an offset boom angle of the offset boom mechanism, the offset boom angle detection device comprises a first detection unit and a second detection unit, the second detection unit comprises an angular velocity sensor that detects the offset boom angle based on a change in angular velocity, the first detection unit comprises a magnetic flux sensor unit and a magnet unit attached to the offset boom mechanism so as to rotate relatively in response to changes in the offset boom angle, the magnetic flux sensor unit is disposed opposite the magnet unit in a non-contact state and detects changes in magnetic flux density accompanying the rotational movement, and the work support device identifies the offset boom angle based on detection values ​​of the first detection unit and the second detection unit.

2. The work support system of claim 1, wherein the work support device creates linking information that links the detection value of the first detection unit to the offset boom angle detected by the second detection unit, and after creating the linking information, identifies the offset boom angle based on the detection value of the first detection unit and the linking information.

3. The work support system according to claim 1, wherein the offset boom mechanism comprises: a first boom supported on the main body of the work machine so as to be swingable up and down; a second boom supported on the tip of the first boom so as to be swingable left and right; and a third boom supported on the tip of the second boom so as to be swingable left and right; the offset boom angle to be detected is a relative left and right swing angle between the first boom and the second boom, or a relative left and right swing angle between the second boom and the third boom; the magnetic flux sensor unit is attached to any of the first boom, the second boom, and the third boom; when the magnetic flux sensor unit is attached to the first boom, the magnet unit is attached to the second boom so as to face the magnetic flux sensor unit in a non-contact state; when the magnetic flux sensor unit is attached to the second boom, the magnet unit is attached to the first boom or the third boom so as to face the magnetic flux sensor unit in a non-contact state; and when the magnetic flux sensor unit is attached to the third boom, the magnet unit is attached to the second boom so as to face the magnetic flux sensor unit in a non-contact state.

4. A work support system as described in claim 1, wherein the magnetic flux sensor unit and the magnet unit are each attached to the offset boom mechanism via a mounting stay, and the mounting stay has a magnetic portion that is fixed to the offset boom mechanism by magnetic force.

5. The work support system according to claim 1, further comprising a transmission unit capable of wirelessly transmitting detection values ​​of the first detection unit and the second detection unit, the second detection unit being provided within the transmission unit.

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