DE102007038016A1 - Drehleiter - Google Patents

Abstract

Turntable ladder, Telescopic mast platform or the like, with a telescopic Ladder set or telescopic mast and, if necessary, attached to it Car, which aerial ladder or which telescopic mast a regulation for the movement of ladder parts or telescopic mast parts which is formed such that in the method the aerial ladder or the telescopic mast platform vibrations the ladder parts or telescopic mast parts are suppressed, by bending at least one of the measured quantities of ladder set or telescopic mast in horizontal and vertical Direction, angle of elevation, angle of rotation, extension length and Twist of ladder set or telescopic mast over one Regulator on the control variables for the Drives is returned, characterized in that Ladder set or telescopic mast and / or on-cage inertial sensors for detecting the bending state of the ladder set or telescopic mast are attached.

Description

The The present invention relates to an aerial ladder, a telescopic mast platform or the like, with a telescopic ladder set or telescopic mast and optionally an attached car, in accordance with Preamble of claim 1.

in the Individually, the invention is concerned with an aerial ladder, for example a fire ladder with bendable articulated arm, or similar Device, such as articulated or telescopic mast platforms and Aerials. Such devices are generally rotatable and erectable mounted on a vehicle and can over have a bendable articulated arm, which also has a can be telescopic axis further. The controller is one Railway control, the car or the lifting platform on a predetermined path in the working space of the turntable ladder or lifting platform leads. This vibration and oscillations of the The car or the lifting platform is actively damped.

Controls for turntable ladders, high platforms or the like are made, for example DE 100 16 136 C2 and DE 100 16 137 C2 known. Vibrations of the conductor parts can be suppressed by returning at least one size of the ladder set via a controller to the drive variables for the drives. A precontrol maps the idealized motion behavior of the ladder in a dynamic model based on differential equations and calculates idealized drive quantities for the drives of the ladder sections to allow substantially vibration free movement of the ladder. DE 10 2005 042 721 A1 discloses such control for an aerial ladder carrying at the end of its ladder set an articulated arm to which a car is mounted. Its dynamic properties are incorporated into the dynamic model for mapping the characteristics of the conductors, so that a corresponding control can take place.

Known Articulated ladders or the like are hydraulic by hand lever or electrohydraulically controlled. In the case of purely hydraulic Control is the hand lever deflection directly over the hydraulic control circuit in a proportional thereto control signal for the control block designed as a proportional valve implemented. Attenuators in the hydraulic control circuit can be used to make the movements less jerky and to make it more gentle in transition. However, you can These are not satisfactory for the entire work area Extension length and Aufrichtwinkel be adapted. In addition, this often leads to strongly subdued Settings with sluggish response.

Current orbit controllers actively influence a countermovement in the event of a vibration of the ladder set. However, the vibration is reconstructed only from a strain gauge signal and the underlying model takes into account only the fundamental components. Higher modes of vibration will be in the vibration damping control DE 100 16 136 C2 and DE 100 16 137 C2 and not considered. In addition, the reconstruction of the bending state is based only on strain gauge signals or a reconstruction from the hydraulic pressure signal. However, this is not always sufficient for the present case of vibration excitation of harmonics.

task The present invention is therefore an aerial ladder, a telescopic mast platform or the like according to the preamble of the claim 1, in which the vibration states of the Head or the telescopic mast detected more precisely and can be reconstructed so that active occurring vibrations (either during movement or at rest, z. Due to wind influences or load changes) damped or the conductor end with the car or the Work platform to be guided on a predetermined path can. This should be possible, not to compensate only the fundamental, but also the higher ones Effectively dampen modes of vibration.

According to the invention this task by an aerial ladder or telescopic mast platform solved with the features of claim 1.

According to the invention on the ladder set or telescopic mast and / or on the car inertial sensors for detecting the bending state of the ladder set or telescopic mast appropriate. In this case it is possible to use the inertial sensors either on the ladder set or telescopic mast, on one attached to it Car or both at the ladder set or telescopic mast and at To install car.

Preferably are on the car and / or at the end of the ladder set or telescopic mast, which is connected to the car, several inertial sensors for measuring the angular velocity in different directions intended.

According to one Another preferred embodiment are further inertial sensors on the car and / or at the corresponding end of the ladder set or telescopic masts for measuring acceleration in different spatial directions intended.

When For example, the use of a Gyroscope platform on the upper ladder section or telescopic mast section or In the car exposed, the up to three sensors in the Cartesian arranged spatial directions for detecting the angular velocity includes. If necessary, this gyroscope platform can three acceleration sensors in the corresponding spatial directions be supplemented.

Further preferred embodiments of the invention will become apparent from the dependent claims 4 to 9.

Especially includes the aerial ladder or telescopic mast platform according to the present invention, a pilot control, which in the method of Car the idealized motor behavior of the ladder or the Telescopic masts in a dynamic model based on differential equations, depicts and idealized control variables for the drives of the ladder parts or telescopic mast parts for a substantially vibration-free movement of the ladder or the Telescope masts calculated from the dynamic model, which dynamic model mimics a mass distribution of the ladder set or telescopic mast.

As also in the prior art, the invention is based Track control with active vibration damping on the basic idea, the dynamic behavior of the mechanical and hydraulic system the aerial ladder or the telescopic mast stage first in a dynamic model based on differential equations map.

In contrast to the registrations DE 100 16 136 C2 and DE 100 16 137 C2 however, as a dynamic model, no approach based on a multi-body elastic model is used as an approximation to the distributed parametric model, but the distributed masses of the ladder set are modeled directly. Here, the mass of the car can still be assumed as a point.

Further preferably is a path planning module for the generation the trajectory of the ladder or telescopic mast in the working space provided that the trajectory in the form of time functions for the Car position, car speed, car acceleration, Carriage pressure and if necessary derivation of the car pressure to a Pre-control block outputs, the drives of the ladder parts or telescopic mast parts controls.

in the The following will be a preferred embodiment of Invention explained in more detail with reference to the drawing.

1 schematically shows the mechanical structure of an embodiment of an aerial ladder according to the present invention;

2 is a schematic representation for explaining the degrees of freedom of the system;

3 schematically shows the control circuit for controlling the movement of the rotary ladder according to the invention according to a first embodiment;

4 shows a further control circuit for controlling the movement behavior of an inventive ladder according to a second embodiment;

5 is a diagram illustrating eigenfunctions of the differential equation for describing the bend; and

6a and 6b are diagrams showing the vibration behavior as a function of time.

While 1 schematically shows the structure of the entire system is based on 2 exemplified the rotational movement of the ladder of the invention. The following description of the invention, by way of example only, is not restrictive to an aerial ladder and is readily applicable to a telescopic mast deck or the like equipped with a telescopic mast. The individual parts of this telescopic mast then correspond to the ladder parts of the ladder set of the aerial ladder described here. Furthermore, the invention is not limited to an aerial ladder with a car, son It can also be used on ladders or telescopic mast platforms without a car.

3 schematically shows a control loop for controlling the movement of the aerial ladder presented here. The measured data from the gyroscope are first corrected for the offset in the model-based evaluation. In the model-based evaluation, the influence of gravity on the strain gauge signal is calculated out by the dead weight of the conductors (also during the movement). In the subsequent modal transformation, the first two modes of the natural oscillation are calculated from these signals. These can then be compensated in separated form via the regulator feedback and thus be damped in the effect dampening the vibration. Compared to the prior art, this achieves not only a damping of the fundamental vibration but also an attenuation of the first harmonic.

An alternative structure is in 4 shown. In contrast to 3 However, here only the fundamental oscillation is extracted from the sensor signals and the components of the higher modes are calculated out via a model-based observer. Although this does not provide any active damping of the 1st harmonic, it is possible to prevent the components of the higher modes from coupling with one another and thus acting destabilizingly on the vehicle through the feedback.

The isolated fundamental is then returned via the feedback active damping on the control input given.

In both structures, it is very advantageous that the desired trajectories are guided by a model-based precontrol and are thus adapted to the dynamics of the system. Thus, excitation of the vibrations can be avoided by the reference variables of the system. Unlike the controls in DE 100 16 136 C2 and DE 100 16 137 C2 However, this method is applicable to the present general non-linear case.

exemplary this is now explained for erecting and tilting. The procedure is directly transferable to the direction of rotation, because the influence of gravitation for the considerations of the dynamic behavior of the ladder is neglected. For the design of feedforward is again on a model with concentrated parameters. The equations of motion for the direction upright / tilt:

Legend:

• L (t)

  temporally changeable Parameter conductor length

  m ₁

  moving mass (more dynamic Share of total mass of ladder set, possibly articulated part and car or lifting platform)

  c _ν (L (t))

  Stiffness depending the ladder length

  d ₄₄ (L (t))

  damping coefficient the conductor depending on the conductor length

  τ _A

  Time constant of the hydraulic drive

  k _A

  gain of the hydraulic drive

  φ. _D (t)

  temporally changeable Parameter rotation speed

  ν. _y (t)

  temporally changeable Parameter Deflection at the end of the conductor in the horizontal direction

The Model equations according to Eq. 1 are now in the generally non-linear State form transferred.

Control input is the voltage at the proportional valve of the hydraulic u (t), the target speed φ. A target can be interpreted. With Eq. 1, one then obtains the following non-linear equation of state with the initial equation for the car position taking into account the bending:

For the further system analysis is relative to the relative degree of the system of the selected output. The relative degree of y (t) from Eq. (3) is equal to 2. This is smaller than the system order (n = 4). Therefore, a differential flat input with relative Grade r = 4 chosen:

There he first approximates the real controlled variable (Car position taking into account the bend) corresponds is going to solve the residual dynamics for the production omitted the reference trajectories.

The flatness-based analysis as well as the draft is done according to Rothfuß R .: Application of the flatness-based analysis and control of nonlinear multivariate systems, VDI-Verlag, 1997 fully included.

Becomes φ. D = 0 and ν. y = 0 assuming that, based on the flat exit of the car position, the following parameterization results:

The new input of the system comes with ν (t) = z .... (t) and the inverse control law for precontrol follows:

This can be generated by Solltrajektorien over time for the car position and their derivatives as input information an ideal control variable for the valve position without natural oscillations are excited when moving the ladder. Residual vibrations occur due to model inaccuracies and external disturbances (loading, unloading of the load in the car, wind attack) and are damped by the feedback.

In the case of the structure of 3 the feedback is achieved by a modal decomposition of the measurement signals from the strain gauges and the gyroscope and the return of the separated vibration signals.

The modeling as distributed mass for the ladder set and a point mass for the car at the end of the ladder set leads to the fact that the boundary conditions of the dynamics of the concentrated mass must be fulfilled. Although the vibration of the ladder is considered in the vertical plane (which may be tilted by a certain angle of elevation), the influence of gravity on the concentrated mass is neglected because the mathematical model for small angles can be considered linear and the stationary solution of the problem takes into account the influence of gravity. Therefore, this influence can basically be eliminated in advance for the purpose of vibration damping. The ladder set is moved in the plane of rotation by a moment M (t) at z = 0 of the ladder set ( 2 ). L is the length of the ladder, θ (t) corresponds to the angle of rotation. w (z, t) is the bend. M _p and J _p is the mass of the car and possibly the articulated arm or the moment of inertia of the car converted into the moment of inertia with respect to the center of gravity of the point mass. Assuming that the angular velocity θ · (t) is small and that Coriolis forces can be neglected, the ladder set can be described as a distributed mass via a Bernoulli bending beam via the following partial differential equation, all in all by the second derivative by time marked acceleration terms the rotation of the ladder set by the rotation angle θ (t) is additionally taken into account:

Eq. (7) is the partial differential equation that describes the bend. E is the modulus of elasticity, I is the area moment of inertia of the ladder, ρ is the density, S the (equivalent) Cross-sectional area of the ladder set.

Eq. (8) - (9) are corresponding to a clamped beam end Boundary conditions at the beginning of the ladder set at z = 0.

Eq. (10) and (11) are the transitional conditions between distributed and concentrated mass corresponding boundary conditions, where the Eq. (10) the balance of the moments and the Eqs. (11) the Describe balance of forces.

For simplicity, the following variable is introduced, describing the movement of individual points of the ladder set in the inertial space: V (z, t) ≜ θ (t) z + w (z, t)

In order to the system can be written according to equation 7-11 when

to Simplification is introduced as input:

The Dynamics of the drive system is not considered. From the above input however, the moment M (t) can immediately be determined according to the following Be calculated context:

J _h is the moment of inertia of the conductor gear (15).

The solution according to Eq. (12) - (16) can be represented in the following form. V (z, t) ≜ V H (z, t) + V I (z, t) (19) where V _I (z, t) is the part of the general solution V (z, t) that satisfies only the inhomogeneous boundary conditions of Eq. (13) - (16) while V _H (z, t) satisfies the homogeneous boundary conditions as well as Eq. (12). As an approach for V _I (z, t) is chosen: V I (x, t) ≜ f (z) u (t) where f (z) ≜ A + Bz + Cz 2 + Dz 3 + Ez 4 + Fz 5 , z ∈ [0, L]

From (13) and (14) follows:
A = 0, B = 1.

Around to meet the boundary conditions (15) and (16), the following equation system are solved:

Eq. (20) has a clear solution:
C = -4L ^-1 , D = 6L ^-2 , E = -4L ^-3 , F = L ^-4

Of the Approach to Eq. (19) is now in the Eqs. (12) - (16) used. The equation system follows from this:

to Simplification has been substituted:

As approach for the homogeneous solution is chosen: V H (z, t) ≜ Z (z) T (t). (27)

Becomes (27) in homogeneous part of Eq. (21) used to get: EI Z (IV) (z) T (t) + ρSZ (z) T .. (t) = 0. (28)

The following is now assumed to be a set of functions
{Z _n (z)} _{n ≥ 1,} {T _n (z)} _n≥1

wobei
η ≜ ρS/EIEq. (28) and the boundary conditions Eq. (22) - (25). Eq. (28) can then be written as

in which
η ≜ ρS / EI

zum Eigenwert λ_n ist.λ _n is the associated eigenvalue. From (29) the following differential equation can then be formulated for the amplitudes of the time functions T _n (t). T .. n (t) + ω 2 n T n (t) = 0, (30) in which

to the eigenvalue λ _n .

With (29) and using the approach (27) in (22) - (25) one can formulate the following boundary value problem for the location-dependent eigenfunctions Z _n (z). Z (IV) n - λ n Z n = 0, (31) T n Z n (0) = 0, (32) T n Z I n (0) = 0, (33) T n Z II n (L) = μT .. n Z I n (L), (34) T n Z III n (L) = κT .. n Z n (L). (35)

With the Gl. (24), the remaining time functions T _n (t) in (34) - (35) can be eliminated. This yields from the boundary conditions (32) - (35): Z n (0) = 0, (36) Z I n (0) = 0, (37) Z II n (L) + λ n ( μ η ) Z I n (L) = 0, (38) Z III n (L) + λ n ( κ η ) Z n (L) = 0. (39)

hat, kann die allgemeine Lösung in der folgenden Form geschrieben werden.The solution leads to the following relationships. Because the characteristic polynomial (31) is the roots

The general solution can be written in the following form.

The boundary conditions (36) - (37) at the boundary z = 0 lead to immediate
C _n = -A _n, D _n = -B _n
and:

The Boundary conditions (38) - (39) on the edge z = L lead to the following linear algebraic equation system

der trigonometrischen und hyperbolischen Funktionen weggelassen. Das homogene System (42) hat nicht-triviale Lösungen, wenn die Determinante der Koeffizienten 0 ist.To simplify the argument

the trigonometric and hyperbolic functions are omitted. The homogeneous system (42) has non-trivial solutions if the determinant of the coefficients is 0.

This transcendental function can only be solved numerically with respect to the eigenvalues λ _n . (where the number λ = 0 corresponds to a trivial solution of the problem and is therefore not an eigenvalue). The eigenfunction to eigenvalue λ _n can now be written as

In 5 the first three eigenfunctions of the problem are represented in standardized form (Z _i0 , i = 1, 2, 3) by way of example. Based on these results, the modal representation of the distributed parametric system is derived. The part of the solution containing the homogeneous boundary conditions as well as the Eq. (21) triggers can now be written as

f * / k, f *(IV) / k sind die Koeffizienten vonIf (43) in Eq. (21) used, you get

f * / k, f * (IV) / k are the coefficients of

With (44) all time modes (amplitudes of eigenfunctions) in the frequency domain over the Laplace transformation in the following form.

in the Frequency range is therefore obtained with (19)

For simulation purposes it is now possible to use N modes (ie the first N summands of the infinite series (45) - (46)). For the controller design that follows, the modal representation is selected as follows: V * k (t) = V * Hk (t) + V * Ik (t), k ≥ 1, (47) in which
V * / Ik (t) = f * / ku (t)
out
V _I (z, t) = f (z) u (t)
is determined. With (44) and (47) one then obtains

By way of example, only the first two modes are considered. If you do this the state sizes
x ₁ (t) ≜ V ₁ * (t), x ₂ (t) ≜ x. ₁ (t) = V. ₁ * (t),
x ₃ (t) ≜ V ₂ * (t), x ₄ (t) ≜ x. ₃ (t) = V. ₂ * (t).
the result is the state space representation

Based on this representation, the controller design is now performed. This is the working point
V ₀ (z) ≡ 0, ∀ z ∈ [0, L]
considered. For the technical realization, it has proved sufficient to consider the controller design only the first two modes of the system, since the cutoff frequency of the hydraulic system is about 3-4 Hz, the third mode, however, is about 6.5 Hz. Therefore, the higher modes are neglected. In order to stabilize the system (48) with 2 conjugate complex pole pairs with a state feedback lying on the imaginary axis, since there is no attenuation in the presented model view, all state variables x ₁ to x _{4 must} be measurable. For this purpose, a strain gauge sensor on the lower ladder section and a gyroscope on the ladder point are available as measured variables. The idea is now to estimate the amplitude components of the modes at the oscillation from these sensor values in an observer structure, which also combines the two measured values (that is, fused). The strain gauge sensor at mounting location z = z1 provides a bend value that can be written in the present notation as follows:

Of the Measured value of the gyroscope (mounted at point z = z2)

If Only 2 modes can be considered, the two readings over the state variables are expressed as follows become:

Around all state variables are to be reconstructed 2 more signals required by integration or real differentiation can be gained.

Then can estimate the amplitudes of the modes from the solution of the following algebraic system of equations.

After inversion of the matrix with the eigenfunctions Z one has a direct functional relationship between the measured values at the strain gauge and the gyroscope and the amplitudes for the first two modes. This can then be directly designed a Polvorgaberegler. u (t) = K [x ^ 1 (t) x ^ 2 (t) x ^ 3 (t) x ^ 4 (T)] T . where the gain matrix is the determinant of
A - BK
is determined by specifying the zeros of the characteristic equation. 6a and 6b show by way of example the damping characteristics of the control. In 6a is the bend b (L, t) plotted against time, in 6b the manipulated variable. The control is switched on in the case shown here after ten seconds.

The following is the alternative structure of 4 explained, in which the basic vibration is separated from the measurement signals in a model-based observer. This block will now be described in more detail below.

Of the Disturbance observer for the Sensor data fusion from gyroscope measurement at the basket attachment and the strain gauge at the clamping of the ladder should the Separate the fundamental wave of the bending vibration from its dominant harmonics, to reinforce the return To exclude the harmonics as far as possible.

For the observer becomes simple vibrational differential equations as a model equation. Since the gyroscope signal of a considerable Offset is superimposed in the model equations for this an integrator perturbation model provided for this influence to be able to compensate.

The parameters ω _i , D _i and K _i are determined by experimental process analysis. In the state representation, this then corresponds to:

The first component of the output vector corresponds to the DMS signal, the second component of gyroscope measurement.

∧ [1, 5] ableiten lassen. Nach Transformation auf die Beobachternormalform 2. Art für Mehrgrößensysteme wird aus Gl. 51.For the observer's design, for example, a method based on the representation as the observer's standard form may be selected. It is advantageous that then simple design equations for the observer feedback matrix H on the pre-given poles p _i , i ∈

Ab [1, 5] can be derived. After transformation to the observer standard form 2. type for multivariable systems, Eq. 51st

Of the Observer is thus able to get out of the disturbed (by Harmonics etc.) Measurement signals from strain gauges and gyroscope a reconstructed estimated signal for to generate the fundamental, that then via the feedback dampening the conductor vibrations.

in principle It should be noted here that all previously presented approaches transmitted in an analogous manner to the direction of rotation of the ladder can be.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10016136 C2 [0003, 0005, 0015, 0028]
• - DE 10016137 C2 [0003, 0005, 0015, 0028]
• DE 102005042721 A1 [0003]

Cited non-patent literature

• - Rothfuß R .: Application of the flatness-based analysis and control of non-linear multivariate systems, VDI-Verlag, 1997 [0034]

Claims (9)

Turntable ladder, telescopic mast platform or the like, with a telescoping ladder set or telescopic mast and optionally a car attached thereto, which turntable or telescopic mast comprises a control for the movement of the ladder parts or telescopic mast parts, which is designed such that when moving the turntable or the telescopic mast stage Vibrations of the ladder parts or telescopic mast parts are suppressed by at least one of the measured variables bending of the ladder set or telescopic mast in horizontal and vertical direction, Aufrichtwinkel, rotation angle, extension length and torsion of the ladder set or telescopic mast is fed back via a controller to the drive variables for the drives, characterized that inertial sensors are mounted on the ladder set or telescopic mast and / or on the car for detecting the bending state of the ladder set or telescopic mast. Turntable ladder or telescopic mast platform according to claim 1, characterized in that the car and / or at the end of the ladder set or telescopic mast on which the car is is mounted, several inertial sensors for measuring the angular velocity are provided in different spatial directions. Turntable ladder or telescopic mast platform according to claim 2, characterized in that the car and / or at the end of the ladder set or telescopic mast on which the car is is attached, further inertial sensors for acceleration measurement are provided in different spatial directions. Aerial ladder or telescopic mast platform after one of the preceding claims, characterized in that the Ladder set or telescopic mast strain gauge sensors for detecting the bending state of the ladder set or telescopic mast are attached. Turntable ladder or telescopic mast platform according to claim 4, characterized in that from the sensor signals of the Inertial sensors and the strain gages by means of sensor data fusion reconstructed the bending state of the ladder set or telescopic mast becomes. Turntable ladder or telescopic mast platform according to claim 5, characterized in that the result of the sensor data fusion a modal transformation to calculate the first two modes the self-oscillation of the ladder set or telescope mast performed is, which are returned to the controller as Ansteuergröße. Turntable ladder or telescopic mast platform according to claim 5, characterized in that from the result of the sensor data fusion only the fundamental vibration of the ladder set or telescope mast is extracted and this as Ansteuergröße the Regulator is returned. Aerial ladder or telescopic mast platform after one of the preceding claims, characterized by a Feedforward, which idealized when moving the car Movement behavior of ladder or telescopic mast in a dynamic Model based on differential equations, maps and idealizes Control variables for the drives of the ladder parts or telescopic mast parts for a substantially vibration-free Movement of ladder or telescopic mast from the dynamic model calculates which dynamic model is a mass distribution of the ladder set or telescope mast. Aerial ladder or telescopic mast platform after one of the preceding claims, characterized in that a Railway planning module for the generation of the trajectory of the Ladder or telescopic mast is provided in the work space, the the trajectory in the form of time functions for the car position, car speed, Car acceleration, car pressure and, if necessary, discharge of the cage pressure to a pilot block that outputs the drives controls the ladder parts or telescopic mast parts.