EP0907805B1 - Method and arrangement for monitoring the working range when an item of machinery is moving - Google Patents

Description

To an increasing extent, attempts are also being made outside the production area and automated production lines in others Areas where automation is not yet ready advanced, also a higher degree of To achieve automation. In connection with agricultural equipment, such as B. tractors, excavators or earth moving machines, So far, there have only been tendencies towards automation. To increase productivity even in such areas it seems sensible to be able to use human operators relieve you of unnecessary work or monitoring tasks. One such aspect is, for example, monitoring one Field of application of such an implement, for example collisions with objects when operating the device manually to be able to reliably avoid in the area.

US-A-5,490,081 discloses a method for monitoring an area of application of an implement is known. At This method is a speed of the implement automatically controlled at the boundaries of the work area.

Such a monitoring process is difficult because today, for example, with excavators, the individual Axles and the drive of the excavator are typically manually controlled by a Device operator controlled. Here it is particularly in narrow work areas, such as B. when excavating a construction pit between two houses, etc. easily possible that the excavator collides with an obstacle when turning or driving. On Another problem is that an attachment of such Device, such as a shovel or other movable boom, in contact with an obstacle causing a collision.

Since the trend for the future also applies to construction machines, Tractors and other earth moving equipment at all times higher levels of automation will result even with increasing automation more and more computer controllable Servo drives, or at least electrically controlled Push through hydraulic valves. To a defined movement control to enable such a device are preferred individual axles of these vehicles can be controlled and increased are also used, for example, angle sensors to the Controls of such devices defined information about the current Give the position and position of the machine and its outriggers to be able to.

So far, no prior art is known that deals with the Monitoring the work area of such a mobile work device deals.

The object underlying the invention is therefore in stating another arrangement and method, with which the monitoring of the work area of a moving work equipment is possible.

This task is for the procedure according to the characteristics of the Claim 1 and for the arrangement according to the features of claim 9 solved.

Further developments of the invention result from the dependent Claims.

There is a particular advantage of the method according to the invention in that with the help of a global positioning system a precise position determination of the device is possible and that in a simple way by specifying a Work area is a defined work area for a work device can be monitored. Preferred for the case that the work area threatens to be left by the device, a signal can be triggered which, for example, the Control of the device causes the movements to slow down or to stop. Preferably also for one human operators of this device trigger an alarm which then signals to the user that this may be can collide with an obstacle which is in the vicinity of the work area.

The movements on the implement are also particularly advantageous attached attachments monitored to determine whether a boom or another movable part, which attached to the implement threatens the work area to leave. It can preferably be provided for this case be the movements of the boom automatically to the predetermined Limit work area. The data which is used for Evaluation of the position and location of the device and its Attachments required are preferred by on the device Angle sensors or similar provided for control measures Sensors submitted and evaluated. Preferably can by the inventive method collisions with obstacles can be avoided by defining the work area so that it does not contain obstacles, or that it definitely contains them circumscribes.

A reference position is preferred at the start of a work process ingested and changes in movement of the implement and any existing attachments, for example by emitting signals from rotary encoders, registered so that an exact statement can be made at any time can be in what position the implement and any attachments provided. In simple This way it can be ensured that no part of the device leaves the work area. Designed to be particularly simple this monitoring, if the kinematics of the device or existing attachments are taken into account, as the kinematics only certain movements are allowed and therefore not all theoretically conceivable movements must be examined, but only those which are due to the kinematics of the device and its attachments are possible.

To ensure an automatic evaluation during the monitoring process facilitate, are preferably individual movable parts of the Tool and its attachments through volume elements enclosed, as a good with as little computing effort Approach to the real state is achieved and in addition yet the advantage is achieved that a safety margin the boundary of the work area can be reached that the volume elements, which circumscribe enlarged become.

The work area, or what is allowed, is particularly advantageous and allowable work volume in the form of a teach-in procedure given, for example, an operator once the entire work volume runs off and attachments, for example according to the defined and permitted work volume moved so that the entire resulting from it Control processes in a control unit of the implement can be saved in order to use it for later work To be able to make comparisons.

The data on the permissible can be particularly advantageous Work area but also in the form of CAD design data be won, since often when building buildings or tunnels anyway the exact geometry of the work area or the Surroundings of the building must be recorded and therefore an exact Description is available, which means that a teach-in process can be saved.

An arrangement for implementation is particularly advantageous of the method according to the invention means for determining the global position ahead and simple means of capturing Movements of the implement and occasionally existing attachments. For example, these motion sensors are in shape of rotary encoders and on a jacking axis of the device provided odometer. These data are preferred by a Evaluation unit related to each other and it is determined whether a predefined work area by the implement or existing attachments are observed. This condition can be particularly advantageous in the event of violations an alarm is triggered if the working area is observed, or the control unit can monitor the movements of the device affect, which means that the unit will be stopped can, or that the movements are adjusted so that the outermost Point of the device of the contour of the working volume follows.

Figur 1

zeigt ein Beispiel eines Arbeitsgerätes in Form eines Baggers

Figur 2

zeigt ein Beispiel eines Arbeitsgerätes in einem Arbeitsraum.

The invention is explained in more detail below with reference to figures.

Figure 1

shows an example of an implement in the form of an excavator

Figure 2

shows an example of an implement in a work room.

In Figure 1, an implement AG is shown in the form of an excavator. If there is talk of excavators in the following, it should this does not mean that the invention is only on excavators is limited. Also related to the invention other land moving devices conceivable, or can the Use of agricultural equipment to be monitored. in the For example, it is related to agricultural machinery conceivable that when editing a field it is monitored whether its limits are strictly observed.

The excavator AG shown in FIG. 1 has antennas, for example A1 and A2 on what data from a global positioning system can be received. In a tax calculator the unit, for example, is accurate to a few cm determined in which position the construction of the excavator located. By controlling the excavator, for example Axes 10 to 50 can be controlled separately. On this Suitable axes are provided, which it the Controls allow the exact position of the respective add-on parts AT to determine. For example, with the Bagger AG an earth excavation can be carried out on a soil BO. The described Axes 10 to 50 allow any degree of freedom. Variable parameters of the device should preferably be used be monitored for all degrees of freedom of the excavator, so it is known at all times in what position the excavator is and which contour the intended, for example Attachment AT takes. About AT attachments it can be said that these are not generally movable as they are have kinematics given by their geometry. This Kinematics here is due to the degrees of freedom, for example the axes 10 to 30 indicated. If by a tax calculator or should be checked by other means whether the implement AG or an attachment a predefined Leaves work area so can by using the control the kinematics and using angle encoders or other measuring devices, which are provided on the corresponding axes, can be determined very easily which final geometry of the attachment is taken. In connection with the exact Position of the implement, which via the global positioning system a position of an am farthest point, the far point, which should preferably be monitored. In Figure 1 there are two such distant points entered FP1 and FP2. To be favoured when determining position GPS / DGPS exhausted possibilities, with which the position of a mobile vehicle, such as the work tool AG, determined as precisely as possible can be. By knowing your own position and orientation of, for example, construction equipment, and one by for example a work area entered by an operator, knowledge of the articulation angle and the dimensions of the construction equipment and occasionally other parameters it is at any time possible to decide whether the work tool AG in permissible work area is or is about to be to leave. In this case, a warning signal, which is addressed to the operator of the device and / or the movement of the device first slowed down and then stopped altogether, for example to avoid an accident.

Figure 2 shows the implement AG of Figure 1 in connection with a permissible working area AZU, being essential Parts of the implement with volume elements V10 to V70 are circumscribed. The use of solid elements in the Monitoring the work area AZU allows the computing effort for the calculations to be carried out, since not the real dimensions, but approximate Dimensions have to be considered. In particular then only cuboids and simple volume blocks can be expected. The permissible work area AZU shown here is here represented simply as a cuboid or as a surface. There are but also any three-dimensional structures conceivable and definable. For example, an allowable work area can be entered in the form of a teach-in process, in which an operator with the work tool AG and existing ones Add-on parts the entire work area in one step, which should be allowed afterwards leaves while moving existing attachments so that they the desired Do not violate the boundary of the work area. From one Control of the device can perform the specified movements can be saved and used later during work these control positions can be updated with the device entered control positions of the operator compared become. When entering three-dimensional structures plays when learning, the current position of the implement AG a role that over the global positioning system is obtained and preferably in connection with everyone currently performed movement is stored. If one Violation of the permissible work area occurs the control unit emits an alarm signal or cause that the device at all times with its boom AT in the permissible Working area AZU remains by controlling automatically Control commands of the operator modified. The allowable work area AZU can also be specified inversely, for example, by only avoiding obstacles should be marked explicitly. Preferably, the permissible Work area AZU can also be entered in the form that Data from an existing CAD model of the work area available. Design data are conceivable here, for example, which is an architect when measuring the terrain and in the construction of a building or excavation has already entered, which then only the Control of the device communicated or supplied electronically Need to become.

The method according to the invention is preferably carried out cyclically. In a first step, for example Position and location determination of the device by means of GPS receivers. Today's high-performance systems, such as the DGPS allow accuracy in position determination of about 2 cm [Source: Trimble: 7400Msi: High precision GPS receiver for dynamic control systems]. Prefers can be done by attaching two antennas as shown in Figure 1 represented by A1 and A2, by comparing their positions the orientation of the implement can also be determined. Due to the positional inaccuracy of 2 cm Large excavators angular errors of about 0.4 °, this inaccuracy can, however, warn or limit possible collisions be taken into account. With large excavators, for example a range of 15 m can result in maximum inaccuracy Extend up to 12 cm at the tip of the ice bucket.

In a second step, joint angles of the Work tool added, this in different ways for example with potentiometers or resolvers can. However, it is important for the method according to the invention only that the movement changes of the implement be measured precisely and are known.

In a further step, the Knowledge of the own position and the orientation of the implement, as well as the joint angle and the dimensions of each Elements such as the volume elements V10 up to V50 and based on the kinematics of the implement, as well its attachments the exact spatial position of the implement be determined.

A collision test can then preferably be carried out in a further step each one of these excavator room elements with the given one Work area. This is preferred check every time whether there is an excavator space element critically close to the work area or work volume limit approximated. But preferably also only a far point FP1 can be determined, which is for example in a suitable manner from the kinematics of the attachment and derives the implement AG. For example this is a point that is furthest away from the working device AG. Such points are shown in FIG described with FP1 and FP2. If such points are determined This ensures that there are other points on the device by no means closer to the border of the work area can be located as this.

In a further step, such a critical approximation are detected and a warning tone is emitted, which, for example, the movement of the implement first slows down and finally stops.

The individual steps of the method according to the invention can carried out cyclically in a recurring order become.

Claims (10)

1. Method for monitoring the work zone during the movement of a machine,

   a) in which a permissible work zone (AZU) for the machine (AG) is specified,

   b) in which the current position of the machine (AG) is determined using data from a global positioning system (A1, A2), characterized in that the work zone (AZU) is monitored by checking whether the machine (AG) is in the work zone (AZU) using the dimensions of the machine (V10-V70) in conjunction with the current position of the machine (AG).
2. Method according to Claim 1, in which the work zone (AZU) of the machine (AG) is limited by a signal being triggered before the machine (AG) leaves the permissible work zone (AZU) and the limitation being brought about by means of this signal.
3. Method according to one of the preceding claims, in which the work zone (AZU) for the machine (AG) is specified in the form of a three-dimensional working space (AZU), and at least one movable attachment (AT) mounted on the machine (AG) is monitored in conjunction with the machine (AG) by determining at least one location of maximum remoteness from the machine (AG) as a remote point (FP1, FP2), said location being on the movable part, from the kinematics of the movable part and its dimensions and from the location at which it is mounted on the machine (AG), and monitoring this remote point (FP1, FP2).
4. Method according to one of the preceding claims, in which a collision between the machine (AG) and an obstacle is excluded by specifying the work zone (AZU) in such a way that it does not contain the obstacle.
5. Method according to one of the preceding claims, in which, starting from an initial position of the machine (AG) in the work zone (AZU), all movements of the machine (AG) and any attachments that may be present (AT) are monitored within the respective degrees of freedom (10-50) and changes in location are noted, with the result that the position and location within the work zone (AZU) are known at all times for monitoring purposes.
6. Method according to one of the preceding claims, in which, to make the computation process easier in the case of automatic monitoring, the dimensions of at least part of the machine (AG) are approximated by the dimensions of a volume element (V10-V70) surrounding this part.
7. Method according to one of the preceding claims, in which the permissible work zone (AZU) is specified by means of a learning method in the form of a teach-in method, with an operator specifying the dimensions of the permissible work zone (AZU) manually by travelling the permissible work zone and possibly moving movable attachments (AT) and storing these dimensions.
8. Method according to one of Claims 1 to 6, in which the permissible work zone (AZU) is specified in the form of data from a CAD system.
9. Arrangement for carrying out the method according to one of the preceding claims,

   a) in which first means are provided for determining a global position (A1, A2),

   b) in which second means are provided for detecting movements of the machine (AG) and any attachments (AT) that may be present,

   characterized in that third means are provided for evaluation, these means performing monitoring using the data output by the first and second means and stored information on the permissible work zone (AZU).
10. Arrangement according to Claim 9, in which the third means are connected to means for controlling the machine (AG) and, if monitoring shows that there is a risk of the work zone (AZU) being exceeded, the movement of the machine (AG) is modified.

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