WO2002092921A1

WO2002092921A1 - Working device for finishing work with a limited working range

Info

Publication number: WO2002092921A1
Application number: PCT/DE2002/001704
Authority: WO
Original assignee: Schenk, Jürgen
Priority date: 2001-05-11
Filing date: 2002-05-10
Publication date: 2002-11-21
Also published as: DE20108012U1

Abstract

The invention relates to a working device which is essentially provided for carrying out finishing work. Said device comprises a support device with an extension arm mounted thereon; a working tool which is connected to the extension arm and which is used to perform work; an actuating device for targeted movement of said working tool; at least one operational element for the person using the working device, which provides the actuating device with control signals which are used to control the position and the work of the working tool, and a sensor device which provides signals corresponding to the position of the working tool. A control device detects the position of the working tool on the basis of the signals provided by the sensor device and verifies the control signals to the actuating device. If necessary, said control device modifies the latter in such a way that it inhibits/and or prevents approximation with a fixed limiting curve.

Description

WORKING MACHINE FOR EARTHWORK WITH A NARROWABLE WORKING AREA

The invention relates to an implement, in particular for earthworks.

Excavators, wheel loaders and other devices that can carry and guide various tools, such as spoons, milling machines and the like, are used to excavate, remove or refill soil. The implements can be provided as stand-alone units or with a self-propelled undercarriage. The positioning and operation of the tool and, if necessary, the implement usually follows manually by an operator.

Based on their experience, the operator can coordinate different work processes. If, for example, a trench is to be dug with an excavator, the soil is removed until the desired trench depth is reached.

If pipes are to be laid in the trench, it is important to maintain a required trench depth. This even if the excavator is moved or the terrain profile is not level. Digging out predetermined soles or profiles requires practice. If specifications are not achieved precisely enough, reworking may be necessary.

Based on this, it is the object of the invention to design a working device in such a way that its operation is facilitated. It is also an object of the invention to provide a corresponding method which allows precise work.

These interrelated tasks are solved by the implement according to claim 1 or the method according to claim 17 and / or 18.

The working device according to the invention has a carrier device with a boom on which a working tool is mounted. The work tool and / or the boom can be moved in a targeted manner with an actuating device. To control the movement, one or more operating elements are provided for the operator, which give corresponding control signals to the actuating device. A sensor device detects the movement or the position of the work tool and provides signals that indicate its position. A control device is provided which monitors the position of the working tool on the basis of the position signals supplied by the sensor device and the control signals from the operating device. When the work tool approaches a definable limit curve (sole, horizon or profile), the control device changes the control signals in such a way that the approach is inhibited and an exceeding of the limit curve is prevented or at least limited. The change in the control signals can include the generation of additional signals, the reduction of existing signals and the increase in individual signals.

The implement is particularly suitable for carrying out earthworks. If, for example, a trench of a certain depth is to be opened in order to lay lines or pipes in it, or if excavation is to be carried out for a building, the desired depth can be defined as a limit curve, for example. The operator can operate the implement and the working tool in the usual way. She is not hindered in her workflow. The control only intervenes when the limit curve is threatened and then prevents an illegal operation. The risk of incorrect operation as a result, for example, of a lack of concentration is thus reduced.

Working tools are in particular excavators or wheel loaders but also other devices. In addition to movements of the work tool, the control device can record the movements of the device in order to take them into account when correcting the manually initiated work movement. The boom can be pivotally mounted on the carrier device, for example, in order to enable the work tool to be raised and lowered. The position of the boom can be detected with the sensor device and information about it can be transmitted to the control device.

The boom can have a plurality of boom arms or segments which can be pivoted or moved with respect to one another with the actuating device. The sensor device can then preferably detect the position, the effective length and the like of each boom segment and transmit the corresponding signals to the control device, which signals the relative position of the work tool from the vehicle.

An actuating device with drives and power transmission devices is provided for extending or swiveling the boom or the boom segments. A drive is advantageously assigned to each boom segment. This can be formed by a hydraulic piston-cylinder unit which can be controlled, for example, by means of servo control valves.

Shovels, milling machines or combined excavator buckets are usually used to carry out earthworks. However, the work tool can be of any design. In one embodiment, information about the size of the work tool can also be taken into account by the control device. If the working tool, for example. Is pivotably mounted on the boom, one or more sensors, for example. ^', Provide information on the pivoted position to the controller the angular position sensors. IA, the control device does not change the control signals generated by the operating elements and merely monitors the workflow permanently. This has the advantage that the operator is not unnecessarily impaired in his work and can handle the implement as usual. However, the control device intervenes in a controlling manner if the work tool approaches an impermissible limit curve in an impermissible manner. The size and position, for example the tilting position, of the working tool is preferably taken into account here. A tolerance range can preferably be defined, within which the control of the movement of the work tool is taken over by the control device. The control device according to the invention allows narrow tolerance limits which are in the range of a few centimeters. If necessary, speed signals can also be taken into account in addition to position signals in order to be able to intervene earlier if the limit curve is approached quickly.

If the control device takes control, it generates new control signals that take precedence over the control signals of the control elements, or modifies the signals of the control elements. The latter are not passed on to the actuating device, or only in a changed manner. However, they are preferably used in the determination of the new control signals. In practice, it can be enough to influence a single signal. For example. For a backhoe, the working depth can be effectively limited if the first segment mounted directly on the vehicle is raised if necessary. For example, it can be brought about that the work tool is guided along the limit curve in accordance with the movement desired by the operator, without at least substantially closing it exceed. Only the movement component directed perpendicular to the limit curve is inhibited. In spite of the control effect of the control device, the operator can consequently continue to operate the work tool and, for example, make a correction to the movement path. If the working tool is sufficiently removed from the limit curve, the control device returns control completely to the operating elements and thus to the operator by forwarding their control signals to the actuating device in an unadulterated manner.

The control device can be switched off if necessary. This can be useful for certain tasks, e.g. for compacting the subsurface.

A straight line or plane is defined as the limit curve, which is preferably arranged horizontally. Such a limit curve can be determined by specifying a single point or limit value. The limit curve can also be inclined and have steps or other, more complex shapes and can be programmed if necessary.

A reference level, for example the floor level at which the implement is installed, can be specified and the limit value can be determined in relation to this level. If the working device is to be experienced when carrying out the work, a leveling system, for example a laser reference system, can be provided. Changes in the position of the implement can thus also be evaluated by the control device when determining the path of movement of the implement. In a particularly advantageous embodiment, the limit curve is determined by using the work tool to place a point (reference point) is touched, which should serve as a reference point or limit. As long as the implement remains in place, the setting applies. If it is moved, it can be reset to the limit curve by touching the reference point again. The reference point does not have to lie on the limit curve.

The limit value or the limit curve can preferably be readjusted and stored as often as desired. Suitable storage means are available for this. An input device can also be provided in order to be able to determine the limit value and possibly further parameters such as the slope of the limit curve, the tolerance range, etc.

The control device can have an integrated circuit and a processor on which a program for executing the necessary arithmetic operations can run. The program can be adapted to the respective requirements and saved.

Further advantageous details of embodiments of the invention result from the dependent claims, the drawing and the associated description.

In the drawing, an embodiment of the object of the invention is shown. Show it:

1 is a working device according to the invention, with a representation of the control device and the control paths, in a simplified and schematic view,

Fig. 2 is a simplified block diagram showing the Control of the work tool of the implement illustrated in FIG. 1, and

3 shows a detail of the working device from FIG. 1 with a movement path of the working tool to illustrate the control effect of the control device, in a schematic representation.

1 shows a simplified illustration of a working device 1, which in the present example serves for excavating and removing soil and has a carrier device 2, a boom 3 and a working tool 4, which is designed here in the form of a shovel 5.

The carrier device 2 preferably has a lower undercarriage 6, which allows the working implement 1 to move forwards and backwards, and an upper structure 7, which can be pivotably arranged on the undercarriage.

The boom 3 is formed in several parts in the present exemplary embodiment and is pivotably articulated on the structure 7 in the vertical plane with a boom segment 8a. The individual boom segments 8a, 8b, 8c are connected to one another via joints to form a chain and can be pivoted relative to one another. An actuating device 9 is provided for carrying out these pivoting movements. For example. For each boom segment 8a, 8b, 8c, a drive 9a, 9b, 9c, for example a hydraulic piston-cylinder unit, can be provided, with which the relative angular positions 10a, 10b, 10c of the boom segments 8a, 8b, 8c can be varied. Control valves, which are not further illustrated, can also be provided here, which open or close more or less depending on the operation and thus extend and retract the hydraulic cylinder pistons, thereby causing the boom segments to pivot. In any case, the work tool 4 can be raised, lowered and moved forwards and backwards within certain limits by pivoting the boom segments 8a, 8b, 8c. The work tool 4 is connected to the outermost boom segment 8c. It can be rigidly connected to it or, as shown in FIG. 1, it can be pivoted or tilted on it. An additional drive 9d is provided in the actuating device 9 for tilting the working tool 4. The position of the working tool 4 is clearly defined by its tilt angle lOd.

For moving the undercarriage 6, for pivoting the body 7 and for controlling the working movement of the boom segments 8a, 8b, 8c and the working tool 4, an operating element 11 is provided, which was only shown schematically in FIG. 1. In general, the control element 11 is integrated in the carrier device 2, for example in the form of levers and pedals, which can be operated manually, for example. Among other things, it supplies control signals to the drives 9a, 9b, 9c and 9d in order to move the working tool 4 in different working positions. As a result, the relative angles 10a, 10b, 10c of the boom segments 8a, 8b, 8c and the tilt angle 10d of the working tool 4 are changed. A sensor device 12 is provided, which in the present case consists of the angular position sensors 12a, 12b, 12c and 12d and with which the relative angles 10a, 10b, 10c and 10d can be detected. _, To detect the position of the boom segments 8a, 8b, 8c and the working tool 4 and for the control, linear sensors can also be used, for example, with which the stroke of the piston rods of the piston-cylinder units is measured.

The implement 1 also has a control device 13, which also serves to control the boom segments 8a, 8b, 8c and the implement 4. It receives signals that correspond to the positions of the boom segments 8a, 8b, 8c and the working tool 4 correspond, from the sensor device 12, in particular from the angular position sensors 12a, 12b, 12c and 12d (dashed lines in FIG. 1) and the control signal supplied by the operating element 11. In addition, the control device 13 receives information about the course of a limit curve 14, which, for example, defines the maximum depth and the course of the trench to be excavated.

Any limit curves 14 can be defined. The control device 13 preferably includes means for entering and storing the limit curve 14, which are not illustrated further here. This can be specified with reference to a reference level, for example the ground reference level 15 or a level defined by a laser guidance system.

The implement 1 according to the invention operates as follows, as can also be seen from the block diagram in FIG. 2:

With the implement 1, for example, a trench of a certain depth is to be opened. The operator of the working device 1 probes with the working tool 4, for example at an already opened section, a reference point which has the desired depth and specifies the limit curve. The reference point can be a point 16 on the top of an already installed pipe, which can be readjusted quickly and exactly at any time, for example by moving the implement, regardless of the contact area. The value is preferably stored temporarily by pressing a key. In addition, an offset value is entered (or otherwise taken into account) that is the vertical distance represented between the upper edge of the pipe and the bottom of the trench. If necessary, the operator enters additional parameters for defining the limit curve by means of a user input.

Then the operator controls the work tool 4 in an appropriate manner with the aid of the operating member 11 in order to dig with it. The control element 11 supplies the necessary control signals to the actuating device 9, which consequently pivots the working tool 4 and the boom segments 8a, 8b, 8c against one another. This changes their relative angular positions 10a to 10d, which are detected by the sensor device 12 and sent to the control device 13 in the form of suitable, preferably electrical signals. From these signals, the control device 13, when switched on, can determine the current position of the work tool 4. It also preferably takes into account the tilting position and the type and dimensions of the working tool 4. It compares its position with the limit curve 14 and does not intervene in the workflow as long as the distance from the limit curve is sufficient, for example outside a predeterminable tolerance range 17 ,

The effect of the control device 13 begins automatically when the tolerance range 17 is undershot, ie the work tool 4 is moved inadmissibly into the vicinity of the limit curve 14. Then the control device 13 switches at least to priority for the drive 9a and switches it on in a suitable manner. IA, it is sufficient to raise the boom segment 8a mounted directly on the carrier device 2 in order to prevent the curve 14 from falling below. If necessary, the drives 9b, 9c and 9d are also supplied with suitable control signals. In the simplest case, the control device 13 can inhibit the movement of the working tool 4 and bring it to a standstill. However, it preferably filters the control signals of the operating member 11 in order to hinder the operator as little as possible and to convert the desired but inadmissible working movement of the working tool 4 into a permissible one.

FIG. 3 shows such a trajectory 18 of the implement 4 that the operator wanted, which would exceed the limit curve 14. However, the control device 13 increasingly inhibits the movement component directed perpendicular to the limit curve 14 by correspondingly controlling the drive 9a or the drives 9a, 9b, 9c and possibly 9d and ultimately causes the working tool 4 to be moved along the limit curve 14. The new trajectory 19 can be viewed approximately as a vertical projection of the originally intended trajectory 18 onto the limit curve 14. In the steady state, the deviation from the limit curve 14 is only slight. It is preferably only a few centimeters, preferably 1 cm. This enables a more precise positioning of the tool in the immediate vicinity of the limit curve 14 and the execution of precise work.

The operator can operate the implement 1 in the manner he is familiar with and generally does not notice anything at all of the presence of the control device 13. This only intervenes in the workflow if there is a risk of a limit curve being exceeded. The operator no longer has to worry about this. she is supported and relieved by the control device 13 here. As a result, the work can be done much easier and faster.

In order to determine the necessary control signals for the actuating device 9, a powerful processor with a suitable sequence program can be provided, which executes the necessary algorithms and arithmetic operations. The sequence program can be expanded at any time, e.g. adapted to special needs.

A working device 1 provided in particular for carrying out earthworks has a carrier device 2, on which a boom 3 is mounted, a working tool 4, which is connected to the boom 3 and is used for performing work, an actuating device 9 for the targeted movement of the working tool 4 at least one control element 11 for the operator of the working device 1, which supplies control signals for controlling the position and work of the working tool 4 to the actuating device 9, and a sensor device 12, which supplies signals which correspond to the position of the working tool 4.

A control device 13 is provided which detects the position of the work tool 4 on the basis of the signals supplied by the sensor device 12 and which checks the control signals to the actuating device 9. If necessary, it changes this in such a way that an approach to a definable limit curve 14 is inhibited and / or prevented.

Claims

Expectations :

1. work equipment (1), in particular for carrying out earthworks,

with a carrier device (2) on which a boom (3) is mounted,

with a work tool (4), which is connected to the boom (3) and is used to perform work,

with an actuating device (9) for the targeted movement of the working tool (4),

with at least one operating element (11) for the operator of the working device (1), which delivers control signals for controlling the position and the work of the working tool (4) to the actuating device (9), and

with a sensor device (12) which supplies signals which correspond to the position of the working tool (4), and

with a control device (13) which detects the position of the working tool (4) on the basis of the signals supplied by the sensor device (12) and which checks the control signals to the actuating device (9) and, if necessary, changes them in such a way that an approach to a definable limit curve (14) is inhibited and / or prevented.

2. Tool according to claim 1, characterized in that the carrier device (2) has a movable undercarriage (6) and has a preferably pivotable structure (7).

3. Tool according to claim 1 or 2, characterized in that it is designed as an excavator.

4. Tool according to claim 1, characterized in that the boom (3) pivotable on the carrier device

(2) is stored.

5. Tool according to claim 1, characterized in that the boom (3) has a plurality of boom segments

(8a, 8b, 8c) having mutually ^'are pivotable.

6. Tool according to claim 1, characterized in that one or more drives for pivoting the boom (3) or the boom segments (8a, 8b, 8c)

(9a, 9b, 9c) are provided.

7. Tool according to claim 1, characterized in that the working tool (4) is designed as a shovel and / or milling machine.

8. Tool according to claim 1, characterized in that the working tool (4) is pivotally mounted on one end of the boom (3).

9. Tool according to claim 1, characterized in that the signals supplied by the sensor device (12) to the control device (13) of the angular position (10a, 10b, 10c, lOd) of the boom (3) or of the individual boom segments (8a, 8b , 8c) and / or preferably correspond to the work tool (4).

10. Tool according to claim 1, characterized in that the control device (13) changes the control signals for at least one drive when the working tool (4) up to a tolerance range (17), which is preferably only a few centimeters, to the limit curve ( 14) approximates.

11. Tool according to claim 1, characterized in that the signals supplied by the control device (12) have priority over the control signals of the operating member (11).

12. Tool according to claim 1, characterized in that the control device (13) controls the work tool (4) when it approaches the limit curve (14) such that it follows the course of the limit curve (14).

13. Tool according to claim 1, characterized in that the control device (13) can be switched on and off.

14. Tool according to claim 1, characterized in that the limit curve (14) is a straight line and / or can be determined by specifying a single limit value.

15. Tool according to claim 1, characterized in that the control device (13) has means for inputting and storing the limit curve (14).

16. Tool according to claim 1, characterized in that the limit curve (14) with respect to a Laser reference or a ground reference can be set.

17. A method of performing earthwork, comprising the following steps:

Definition of a limit curve (14) which should not be undercut by a work tool (4),

Actuation of operating elements (11) which delivers control signals for controlling the position and work of the work tool (4) to an actuation device (9) in order to move the work tool (4) in a targeted manner.

Detection of the position. of the working tool (4) with a sensor device (12) which delivers corresponding signals,

Monitoring the position of the work tool (4) on the basis of the signals supplied by the sensor device (12) and the control signals to the actuating device (9) with a control device (13) and

if necessary, the control signals to the actuating device (9) are modified by the control device (13) in order to inhibit and / or prevent the work tool (4) from approaching the defined limit curve (14).

18. Procedure for carrying out earthworks with an implement that a working tool (4) which is connected to a boom (3) which is mounted on a carrier device (2),

at least one operating element (11) which supplies control signals for controlling the position and the work of the working tool (4) to an actuating device (9),

a sensor device (12) which supplies signals which correspond to the position of the working tool (4), and

a control device (13) which receives the signals supplied by the sensor device (12) and by the control element (11),

and includes the following steps:

Definition of a limit curve (14) which is intended to restrict the movement of the working tool (4),

Determining the impending actual movement of the work tool (4) in advance on the basis of the control signals supplied by the operating elements (11),

Determination of the required movement of the working tool (4) and required on the basis of the limit curve (14)

Specification of changed control signals to the actuating device (9) if the target movement deviates from the actual movement.

19. The method according to claim 17 or 18, characterized in that the limit curve (14) by default a single limit value, preferably by probing a reference point (16) with the work tool (4) and storing the same.

20. The method according to claim 17 to 19, characterized in that an offset value is taken into account and is preferably programmable, which defines the limit curve (14) with respect to the reference point (16), a laser reference or a ground reference.