EP1246973B1 - Mobile machine with device for controlling the position of working devices and method for controlling the position - Google Patents

Description

The invention relates to a mobile machine with a device for position control Work equipment of the mobile work machine and a Position control method for mobile work equipment Working machine.

DE 197 52 439 A1 describes a micromechanical device Tilt sensor, especially for motor vehicles, as such known, which has a support plate, the inclination is determined to the horizontal. Furthermore, there are at least two pressure sensor units integrated on the carrier plate Determination of one on the carrier plate at the respective Dots applied pressure provided. A ground plate is with the carrier plate over the pressure sensor units connected. From those produced by the pressure sensor units An evaluation unit determines the inclination of the data Carrier plate to the horizontal. The mass plate exercises here after tilting the device into which the tilt sensor built-in, a different force on the respective pressure sensor unit. To measure the Tilt angle must be at least two pressure sensors be provided. These are described in DE 197 52 439 A1 Piezoresistive pressure transducers.

From DE 40 30 954 A1 and US 5,257,177 A is one known mobile machine, which is a device for Has position control for work facilities. The Device for position control includes a measuring device Position sensors for measuring an angle, which between one by the location of the work facility certain plane and the direction of gravitational force is formed, an angle encoder for specifying an angle, which between one by the location of the work facility certain plane and the direction of gravitational force is formed, and a control device for controlling the Angle between the plane of the work equipment and the Direction of gravity so that the measured angle with is brought into line with the predetermined angle.

A device for level control in a harbor crane is known from DE 39 38 766 A1. Here is one Level control using a hydraulic Control valve for controlling one or more hydraulic actuators for a certain level proposed part to be retained, the part with another part that can be changed in any position is coupled. To ensure high operational reliability without To ensure the use of expensive electronics, that stands Control valve with one in its position by gravity fixed pendulum as an actuator in mechanical control connection.

If the device is inclined, it is damped Pendulum deflection in a defined spatial direction, the over transfer the control valve to the hydraulic actuator wind. DE 39 38 766 A1 uses this measure Loading and unloading crane, which is particularly suitable for loading and unloading Unloading of ships is appropriate, so oriented that Raising and lowering the crane boom is a find located on it Discharge device in a fixed position relative remains for the rest of the construction.

A disadvantage of the known from DE 39 38 766 A1 Level control is particularly one-dimensional Execution. For that in the above Laid-open patent disclosed embodiment of the Level control on a loading and unloading crane, preferably for The device is sufficient for ships, for mobile Working machines such as B. earthmoving machines, which preferably on construction sites and therefore on uneven Moving underground is a one-dimensional position correction however not sufficient.

The object of the present invention is therefore a mobile work machine with a contraption for position control of work equipment of the mobile work machine and a method for position control for Work equipment of the mobile work machine to create, making the work facilities both in in several directions as well as on the traffic surface reliable according to the position of the machine can be adjusted without being in uneven terrain Charge loss occurs.

The task is performed by the machine Features of claim 1 and with respect to the method solved the features of claim 10.

The invention is based on the knowledge that the Alignment of a mobile work facility Work machine not alone or immobile when shooting material, but especially when Transport of the picked up material to the site Avoiding charge loss is important. Accordingly, a device designed for this purpose is suitable for alignment with respect to Gravitational force defined plane and in a allow a satisfactorily short time. The Mobile work machine according to the invention with the Device or the corresponding The method provides an arrangement which Position correction with respect to gravitational force and possibly allows inverse acceleration force vertical plane.

The sub-claims 2 to 9 contain advantageous Developments of the invention.

In particular, the possibility of the comparison device both in conventional analog design and in It is an advantage to implement integrated circuit technology because so the special requirements of individuals Working machines can be sufficient.

The arrangement is simple to manufacture and easy to use commercially available sensors.

The arrangement is both for execution in one Suitable for spatial direction as well as in two spatial directions. Especially in earth moving machines Position correction in the longitudinal and transverse directions advantageous. at In a particularly preferred embodiment, the through the normal runtime induced natural vibrations and their multiples eliminated.

The predetermined angle is particularly preferred in this way set that by the location of the work facility defined plane perpendicular to the resultant Gravitational force and inverse acceleration force stands.

As a result, even with accelerations of the work equipment, for. B. through driving movements, the work equipment so positions that loss of charge is avoided. In the drawing, preferred embodiments of the Work machine according to the invention shown and below explained in more detail with reference to the drawing.

Fig. 1

in einem ersten Schaltbild ein erstes Ausführungsbeispiel der Vorrichtung der erfindungsgemäßen Arbeitsmaschine zur Regelung und Ansteuerung von hydraulischen Stellelementen zur Lageregelung beweglicher Arbeitseinrichtungen der mobilen Arbeitsmaschine;

Fig. 2

in einem zweiten Schaltbild ein zweites Ausführungsbeispiel der Vorrichtung der erfindungsgemäßen Arbeitmaschine;

Fig. 3A-3B

den prinzipiellen Aufbau einer als Bandsperre 2. Ordnung ausgelegten digitalen Filtereinheit sowie den zugehörigen Amplitudengang;

Fig. 4A-4B

in einer vereinfachten Darstellung die Bewegung einer mobilen Arbeitsmaschine im Gelände gemäß dem Stand der Technik sowie einer erfindungsgemäßen mobilen Arbeitsmaschine bei Bewegung im Gelände;

Fig. 5

in einer perspektivischen Darstellung ein Beispiel für eine Arbeitseinrichtung einer mobilen Arbeitsmaschine mit den möglichen Schwenkrichtungen;

Fig. 6

eine schematische erfindungsgemäße mobile Arbeitsmaschine mit der Vorrichtung zur Lageregelung in unebenem Gelände; und

Fig. 7

eine Skizze bezüglich einer die Beschleunigung berücksichtigenden Laderegelung.

The drawing shows:

Fig. 1

in a first circuit diagram, a first exemplary embodiment of the device of the working machine according to the invention for regulating and controlling hydraulic adjusting elements for position control of movable working devices of the mobile working machine;

Fig. 2

in a second circuit diagram, a second embodiment of the device of the work machine according to the invention;

3A-3B

the basic structure of a digital filter unit designed as a second-order bandstop filter and the associated amplitude response;

4A-4B

in a simplified representation the movement of a mobile machine in the field according to the prior art and a mobile machine according to the invention when moving in the field;

Fig. 5

a perspective view of an example of a working device of a mobile machine with the possible swivel directions;

Fig. 6

a schematic mobile work machine according to the invention with the device for position control in uneven terrain; and

Fig. 7

a sketch of a charge control that takes acceleration into account.

1 shows a first block diagram of a first exemplary embodiment of the device for position control for work equipment of the mobile work machine according to the invention. The circuit comprises a first sensor 1, which measures a first angle in a first spatial direction, hereinafter referred to as x. This first angle is referred to below as α _x . A second sensor 2 accordingly measures a second angle in a second spatial direction y. The second angle is referred to below as αy. The measured angles α _X and α _Y are obtained via a first comparator 3 and a second comparator 4 with an angle α _x 'for the spatial direction x and α _y ' for the spatial direction y, which angle can be determined by an angle transmitter 5 and which can be 90 °, for example , compared. The comparators 3 and 4 form a comparison device 6. The angle transmitter 5 can either provide a fixed predetermined angle or an angle α _x 'or α _y ' which can be adjusted manually using a manual control transmitter 5a.

The signal in the x-direction passes through a first bandstopper 7 after the first comparator 3, the signal in the y-direction after the second comparator 4 passes through a second bandstopper 8. The bandstopper 7 and 8 have the purpose that τ in the system due to the control run Eliminate the natural vibration f _R and, if necessary, their multiples 2 f _R , 3 f _R , ..., so that the dynamic behavior of the system remains controllable and no resonances occur.

After passing through the bandstop 7, the signal is in the x direction amplified by a first amplifier 9 so as to to be able to control a first electromagnet 10. The first electromagnet 10 is used to actuate a first Control valve 11 required, which in turn a first hydraulic control element 12 for position correction in the controls first spatial direction x. Accordingly it will Signal in the y direction after passing through the bandstop 8 a second amplifier 13 amplified by a second Electromagnet 14 and thus a second control valve 15 head for. The second control valve 15 actuates a second one hydraulic actuator 16. This will Work facility in the second spatial direction y aligned.

To actuate the hydraulic actuators 12 and 16 through a hydraulic fluid in a tank 17 a pump 18 in a front or rear cylinder space of a first cylinder 19 of the first hydraulic Control element 12 or in the front or rear Cylinder space of a second cylinder 20 of the second hydraulic actuator 16 pressed. Through this one experiences first piston 21 and a second piston 22 a Change of position, which in turn for the position control of the Work device 41 provides.

The position control is carried out until the comparators 3 and 4 determine no difference between the measured angle α _x or α _Y and the preset angle a _x 'or a _y '. The differences α _x '-α _x and α _y ' -α _{y become} almost zero in terms of amount or are at least below a value that can still be tolerated for an angular deviation Δα, for example ± 3 °.

If this state is reached, there is no signal change more to the control valves 11 and 15, which then in shift down a middle position without losing position the actuators 12 and 16 to change further. The system remains in the middle position until another one is changed Signal from comparators 3 and 4 is received.

Fig. 2 shows a second embodiment of a Device for position control for Work equipment of the mobile work machine according to the invention. Components that have already been described in Fig. 1 are the same Reference numerals and are not in the following described again. While in Fig. 1 it is a Embodiment is in analog technology, that is in Fig. 2 illustrated embodiment in digital technology executed.

The device shown in Fig. 2 differs of the device shown in Fig. 1 mainly by using a digital control unit 34, which both the function of the band locks? and 8 as well that of the comparison device 6 takes over.

The comparison device 6 is accordingly constructed as follows: The angle α _x output by the sensor 1 is preamplified by a first preamplifier 30 and then by a first analog-digital converter 32 from an analog measured angle value to a digital one which can be processed by a digital control unit 34 Value converted - Likewise, the angle α _y is amplified by a second pre-amplifier 31 and converted into a digital value by a second analog-digital converter 33. In order to be able to compare the predetermined angle α _x 'or α _y ' with the angles α _x and α _y determined by the sensors 1 and 2, the predetermined angle α _x 'or α _y ' is determined by the angle transmitter 5 by a third analog -Digital converter 35 also implemented and supplied to the digital control unit 34, which can be designed as a microprocessor.

The digital control unit 34 is besides comparing the Angle values are also responsible for filtering the signals. To is the filter unit as a digital filter with Bandstop characteristic executed. The Band-stop characteristic corresponds to that in FIG. 1 illustrated embodiment, for example, that in Fig. 3A and 3B illustrated second order diqital band-stop filter and is supported by an appropriate program in the Control unit 34 provided. The digital control unit 34 has a memory 36 which, for. B. the Possibility offers, the measured and compared data to save and for later external processing to provide.

The balanced signals from sensors 1 and 2 are shown by a first digital-to-analog converter 37 and a second Digital-to-analog converter 38 to analog signals reconverted. The analog signals are through Amplifiers 9 and 13 amplified and the electromagnet 10 and 14 fed. Through the control valves 11 and 15, the pump 18 and the tank 17 are analogous to the first Exemplary embodiment hydraulic actuators 12 and 16 driven. These then ensure the correct position of the Work facility 41.

A digital bandpass filter of the second order is explained in FIG. 3A and the associated frequency response is explained in principle in FIG. 3B. FIG. 3A shows a digital filter which, by means of various delay elements for delaying the sampling values (denoted by z ^-1 in FIG. 3A) and coefficient elements a ₀ , a ₁ and a ₂ for changing the amplitude of the sampling values, has a bandstop filter with that in FIG. 3B shown resonance frequency f _R generated. This means that the natural vibration f _{R of} the system, which is caused by the control time τ, and its odd multiples (3f _R , 5f _R etc.) are filtered out. This prevents the system from rocking. This allows a highly dynamic and, on the other hand, extremely precise function of the device according to the invention to be achieved. A further digital filter can be provided to filter out the double resonance frequency 2f _R.

4 is shown schematically using a Working machine 40 with an excavator bucket as Work device 41 an application of the invention in a Dimension explained in more detail.

4A illustrates the prior art. In the lower position of the excavator bucket 41 (left in Image), the excavator bucket 41 is aligned so that a imaginary level 42, which through the overhead opening of the Excavator bucket 41 is placed, always parallel to Surface of the earth. Common machines 40 have thereby a lifting mechanism for the work device 41 on which is designed so that the excavator bucket 41 so The level 42 is raised through the opening the excavator bucket 41 is always set remains parallel to the ground.

As long as the working machine 40 is on a level track is not a problem. As soon as however, work machine 40 up a slope or like Moved down on the right in Fig. 4A, material goes 43 lost because the excavator bucket 41 fixed level 42 still parallel to the ground is and therefore from a certain slope that in the Excavator bucket 41 transported material 43 slips out. The slope angle, from which on with loss of charge is mainly based on the shape of the Excavator bucket 41 and the filling determined.

According to the invention, as shown in FIG. 4B, a different reference plane 42 'is proposed for the alignment of the excavator bucket 41. As in FIG. 4A, an imaginary plane 42 ′ is also defined on the working device 41 of the working machine 40 shown in FIG. 4B through the opening of the excavator bucket 41 located at the top. This is now no longer necessarily parallel to the ground, but always approximately perpendicular to the direction of the gravitational force, marked with the vector g in FIG. 4B. This can be achieved both in the lower and in the upper position of the excavator bucket 41. This offers the advantage that the excavator shovel 41 is readjusted according to the invention when driving uphill or downhill as well as when driving on uneven terrain such that the plane 42 extending through the excavator shovel 41 is always oriented perpendicular to the direction of gravitational acceleration g . This prevents transport losses from the excavator bucket 41.

The one-dimensional correction of the Location of the excavator bucket 41 can easily in two directions perpendicular to one another, for example lengthways and transverse to the direction of movement.

5 shows a schematic excavator bucket 41 for this purpose shown in perspective. By the direction of movement parallel and vertical axes A and B can Excavator bucket 41 both transverse to the direction of travel and in Direction of travel can be swung up and down. So at Driving forward on uneven terrain be avoided to the side from the excavator bucket 41.

6 schematically shows a working machine 40 according to the invention when driving through uneven terrain, the position of the working device 41 also being regulated here by its relative position with respect to the gravitational force g . In this context, it makes sense to assume a limit value for the angle deviation Δα for the angle α between the plane 42 defined by the excavator bucket 41 and the direction of the gravitational force g , from which point the position control can be omitted. As a result, a reasonable middle ground is found between an uninterrupted position correction, which requires a lot of energy and can be unfavorable due to the control delay, and charge loss due to a lack of position correction. The described filter suppresses resonance peaks that can occur when the control excitation caused by the uneven ground coincides with the resonance frequency f _{R of} the system.

While in the exemplary embodiment shown in FIG. 6 the plane 42 defined by the orientation of the excavator bucket 41 is oriented perpendicular to the direction of the gravitational force g , there is also an improved position correction in that the plane 42 defined by the excavator bucket 41 is not perpendicular to the gravitational force g , but to align perpendicular to the resultant r from the gravitational force g and the inverse b 'of the acceleration force b . The excavator bucket 41 is shown enlarged in FIG. 7. It is assumed that the mobile work machine 40 is subject to a deceleration due to a braking operation. The decelerating acceleration force b therefore acts on the excavator bucket 41. On the bulk material introduced into the excavator bucket 41, an inverse acceleration force b ' acts in relation to the reference system of the excavator bucket 41 due to the inertia force b' in the inverse direction of the acceleration force b decelerating the excavator bucket 41, ie the acceleration force b ' acting on the bulk material in the reference system of the excavator bucket 41 however, the same amount as the acceleration force b acting on the excavator bucket 41 in the deceleration direction is rotated by 180 °.

The resultant r from the gravitational force g and the inverse acceleration force b ' therefore acts on the bulk material located in the excavator bucket 41. It is therefore advantageous to regulate the plane 42 by the position control according to the invention so that the plane 42 is perpendicular to the resultant r . For this purpose, in the exemplary embodiments shown in FIGS. 1 and 2, a further measuring device 29 is provided for measuring the acceleration or deceleration of the mobile working machine 40. The acceleration and deceleration can also be measured separately in the dimensions x and y. While in the embodiment shown in FIG. 1 in analog technology, the measuring device 29 for measuring the acceleration is directly connected to the angle transmitter 5 and the angle α _{x ′} given by the angle transmitter 5, in the x direction and the angle α given in the y direction _y ^, overridden, the measuring device 29 for measuring the acceleration in the exemplary embodiment shown in FIG. 2 is connected in digital technology to the control unit 34 via an analog-digital converter 28, which performs a computational correction of the predetermined angles α _x 'and α _y ' depending on the measured acceleration.

This training ensures that Position control of the excavator bucket or generally Working device 41 is carried out so that bulk goods also a stronger acceleration or deceleration of the mobile Work machine 40 is not lost.

The invention is not shown on the Embodiments limited, but can also using any work machines different sensors or filter devices be applied.

Claims (10)

1. Mobile mechanical equipment (40), comprising a position-regulating device for tools (41) of the mobile mechanical equipment (40), comprising a measuring device (1, 2) for measuring an angle (α) that is formed between a plane (42) determined by the position of the tool (41) and the direction of the gravitational force (g), an angle transducer (5) for setting an angle (α') that is formed between a plane (42) determined by the position of the tool (41) and the direction of the gravitational force (g), and a regulating device (3, 4, 6-16, 6, 34, 36, 9-16) for regulating the angle (α) between the plane (42) of the tool (41) and the direction of the gravitational force (g) so that the measured angle (α) is brought into coincidence with the set angle (α'),
   characterized in that a further measuring device (29) is provided for measuring the acceleration and/or retardation of the mobile mechanical equipment (40), and
   in that the set angle (α') is adjusted so that the plane (42) determined by the position of the tool (41) extends perpendicularly to the resultant (r) of the gravitational force (g) and the measured inverse acceleration force (b').
2. Mobile mechanical equipment according to Claim 1,
   characterized in that the regulating device (3, 4, 6-16; 6, 34, 36, 9-16) has a comparison device (6) for comparing the measured angle (α) with the set angle (α') and at least one electromagnetic control valve (11, 15) that is, activated by the comparison device (6) and that acts on a hydraulic actuator (12, 16).
3. Mobile mechanical equipment according to Claim 2,
   characterized in that the comparison device (6) is designed as a comparator (3, 4).
4. Mobile mechanical equipment according to Claim 2,
   characterized in that the comparison device (6) is designed as a digital control unit (34, 36).
5. Mobile mechanical equipment according to any one of Claims 1 to 4, characterized in that the regulating device (3, 4, 6-16; 6, 34, 36, 9-16) comprises a filter unit (7, 8; 34, 36) that eliminates self-oscillation (f_R) caused by the regulating delay time (π).
6. Mobile mechanical equipment according to Claim 5,
   characterized in that the filter unit (7, 8; 34, 36) is designed as band-stop filter (7, 8) for the self-oscillation (f_R) and/or its multiple.
7. Mobile mechanical equipment according to Claim 6,
   characterized in that the filter unit (7, 8; 34, 36) is designed as a digital filter (34, 36) having band-stop characteristics.
8. Mobile mechanical equipment according to any one of Claims 1 to 7, characterized in that the position-regulating device for tools (91) of the mobile mechanical equipment (40) performs a tilt compensation along and transversely to the movement direction of the mechanical equipment (40),wherein a first position-correcting actuator ( 12 ) is activated a first spatial direction (x) and a second position-correcting actuator (16) is activated in a second spatial direction (y).
9. Mobile mechanical equipment according to Claim 8,
   characterized in that a measuring device (1) is provided for measuring the angle (α_x) in the first spatial direction (x) and a second measuring device (2) is provided for measuring the angle (α_y) in the second spatial direction (y).
10. Method of regulating the position of tools (41) of mobile mechanical equipment (40), comprising the following method steps:

    measuring an angle (α) that is formed between a plane (42) determined by the position of the tool (41) and the direction of the gravitational force (g),

    setting an angle (α') that is formed between a plane (42) determined by the position of the tool (41) and the direction of the gravitational force (g), and

    regulating the angle (α) between the plane (42) of the tool (41) and the direction of the gravitational force (g) so that the measured angle (α) is brought into coincidence with the set angle (α'),

    characterized in that the set angle (α') is adjusted so that the plane (42) determined by the position of the tool (41) extends perpendicularly to the resultant (r) of the gravitational force (g) and the inverse acceleration force (b').

Images