EP3584366B1 - Railway carriage - Google Patents

Description

The invention relates to a measuring carriage that can be driven on rails for measuring track geometry, with a measuring carriage frame arranged on a chassis, to which an inertial navigation unit is assigned and which can be adjusted in relation to a console that can be fastened to the machine frame of a superstructure machine, with actuators causing lifting and pressing movements, with two wheels are assigned to the chassis on each side of the measuring carriage and the measuring carriage frame has five degrees of freedom, namely a rotation around the vertical axis of the measuring carriage frame, a rotation around the longitudinal axis of the measuring carriage frame, a rotation around the transverse axis of the measuring carriage frame, a linear movement along the z-axis and one Linear movement of the measuring carriage frame along the y-axis, in particular with respect to the chassis.

Such a track-driven measuring car for measuring track geometry is from AT 519 003 A4 known.

Most railway tracks are designed as ballasted tracks. The sleepers are in the gravel. Irregular settlements in the ballast and shifts in the lateral geometry of the track are caused by the acting wheel forces of the trains running over it. Due to the settlement of the ballast bed, errors in the longitudinal height, the superelevation (in the curve) and the alignment occur. If certain comfort limit values or safety limit values of these geometric variables are exceeded, then maintenance work is carried out.

The removal and correction of these geometric track errors is mostly done today with track construction machines ( AT 519 003 A4 , EP 3009564 A ) carried out. So that the track can be restored after such track geometry improvement work can be released for operation, the track construction machines are equipped with so-called acceptance measuring systems and acceptance recorder systems. Acceptance tolerances are specified for the quality of the track geometry after improvement using superstructure machines or other methods. These represent the minimum requirements for the quality of the generated geometric improvements. These are verified by the acceptance measuring systems and acceptance recorder systems.

A track maintenance machine such as a tamping machine restores the track geometry that has been degraded by the stress on the trains. To do this, the track is lifted into the desired position and straightened using electro-hydraulically controlled lifting and straightening devices. The lateral position of the track (direction) is corrected by lateral displacement of the reference rail of the track with the help of hydraulic cylinders. The rail on the outside of the curve is used as the reference rail for the direction. The rail on the inside of the curve is used as the reference rail for the longitudinal height. The rail on the outside of the curve is corrected in terms of height using the target superelevation in relation to the rail on the inside of the curve.

State of the art are not only measuring tendons but also inertial navigation systems or inertial navigation systems (INS) ( AT 519 003 A4 ) which consist of a central sensor unit with mostly three acceleration and three yaw rate sensors. By integrating the accelerations and yaw rates measured by the IMU (inertial measurement unit), the spatial movement of the vehicle and from this the respective geographic position are continuously determined in an INS. INS systems work with data rates of around 100-1000 Hz and high accuracies and low drift (< 0.01° to 0.05°/ hour). The main advantage of an INS is that it can be operated without a reference. The acceleration can be measured by means of vehicle-mounted acceleration sensors ("strapdown"). Advantages of these measuring systems are roll angles that can be measured independently of the centrifugal acceleration, a transfer function of the system of =1 that applies over a wide range of error wavelengths, ie the actual track of the vehicle in space is measured without distortions the form, the amplification or the phasing of the track errors. 3D coordinates are obtained from this three-dimensional track of the vehicle in space and an equidistant measurement using an odometer. State of the art are also so-called "North"-based INS systems (navigation systems) that provide absolute angular deviations of the roll, yaw and pitch angles in relation to a north-oriented system. The x unit vector points to the north, the z unit vector in the direction of gravity and the y unit vector is then aligned in such a way that an orthonormal system is formed. The absolute angular deviations represent a unit vector that shows the spatial position of the measuring carriage on which the INS system is located.

State of the art is the construction of such inertial navigation systems on electronic track measuring cars. The inertial navigation system is built on a support frame that is attached to the axle bearings of a bogie by stiff spring elements. Since the bogie moves back and forth kinematically on the rails as a result of the track widening, the relative position of the measuring frame on the bogie to the rails must be measured using a gauge gauge. The suspension of the measuring frame and the dynamic vibrations that occur while driving, the indirect, erroneous determination of the lateral position of the measuring frame via track gauges to the track and the inaccuracies in the height as a result of the wheel profile lead to considerable inaccuracies in the measurement. A further disadvantage of this design is that the measuring frame is forcibly twisted and therefore only an average running longitudinal height of the track can be measured. What is interesting, however, is the course of the longitudinal heights of both rails. A mathematical uncertainty (corresponds to twice the standard deviation) of ≤ 1mm is required for the determination of track geometry errors that are to be corrected by track construction machines. These accuracies are difficult to achieve with the aforementioned arrangement of the measuring frame. State of the art are also high-precision angle encoders and sensors integrated in cylinders (hydraulic or pneumatic) for position measurement.

The state of the art of measuring carriages for track geometry measuring systems that work with steel cords are two-wheeled measuring carriages attached to the carriage body of track construction machines via parallel links. These measuring carriages are pressed against the rail either to the left or to the right, depending on the direction of the curve, by means of two cylinders acting diagonally on the outside of the measuring carriage. There are two criteria that must be met for the forces. Firstly, the derailment criterion $${\left(\mathrm{Y/Q}\right)}_{\mathrm{limited}}=1.2\le \mathrm{Y/Q}$$

This means that the ratio of the transverse force Y, which presses the wheel against the rail, to the vertical load Q (formed from the weight force and the force component of the cylinder working at an angle) must be less than or equal to 1.2, so that the wheel flange cannot climb up and the wheel cannot derail is avoided. The second criterion is $$\mathrm{Y}\ge \mathrm{Q}\cdot \mathrm{\mu }$$

This criterion requires that the effective transverse force must be greater than the frictional force (coefficient of friction µ) between wheel and rail. The criterion ensures that the measuring carriage can be safely pressed over the rail. These two conditions severely limit the allowable linkage angles and cylinder forces. On the other hand, the measuring carriages are deflected in curves and by track errors, which is why the articulation angle and thus the force ratios are constantly changing. It is therefore difficult to simultaneously meet the derailment safety criterion and the compression criterion for all cases that arise.

The invention is therefore based on the object of creating a measuring carriage that can be attached to a superstructure machine, which carries an inertial navigation system which is constructed in such a way that it can measure the longitudinal height profile of both rails, the directional profile of the reference rail (rail on the outside of the curve) and the superelevation as precisely as possible . But the invention also has the task of ensuring that the fulfillment of both the derailment criterion and the compression criterion can be ensured.

The invention solves the problem in that the wheels combined into pairs of wheels on each side of the measuring carriage are arranged on a two-armed lever and the levers are mounted such that they can be pivoted about an axis of the chassis that runs through the width of the measuring carriage, that the navigation unit is firmly connected to a pair of wheels and that the axle a rotary encoder is assigned for detecting an angle of rotation between the two levers. So that the longitudinal height profile of the left and right rail can be detected simultaneously, the two wheels on each side are connected to each other via the two-armed lever and these pairs of wheels are designed to be pivotable about the axis. The torsion is measured using a high-resolution rotary encoder (encoder). According to the invention, the navigation unit is permanently connected to a pair of wheels and measures the elevation of this pair of wheels along the rail. The longitudinal height profile of the other rail is determined via the torsion angle. The wheels are cylindrical so that no height error can occur as a result of any wheel profile conicity. The wagon freely follows the track in the vertical direction (z-axis). The direction angle (yaw angle) is recorded by rotating the measuring carriage freely around the z-axis. In order to record the superelevation angle (roll angle), the wagon is designed to be freely rotatable around the transverse axis of the track (x-axis). In order to record the longitudinal elevation angle (pitch angle), the wagon can also rotate freely around the track transverse axis (y-axis). The angles or the changes in angles are measured by the inertial navigation system and transferred to a computing unit for calculating the spatial track of the two rails. The carriage itself is pressed against the reference rail (rail on the outside of the curve) during travel and subjected to a vertical force in addition to its own weight. For this purpose, the wagon can be moved freely in the transverse direction of the track. The lifting and pressing movements are effected by actuators such as hydraulic, electric or air cylinders. According to a further development of the invention, a rotary encoder (rotary encoder) is integrated into at least one of the running wheels for detecting the approach travel. So that the wheels run as slip-free as possible the running wheel surface is decoupled from the wheel flange via roller bearings. The linear movements. (Strokes of the actuators) of the measuring carriage are recorded by displacement sensors. This makes it possible to determine the track widening during compression molding. By recording the vertical cylinder strokes and using appropriate control electronics, the measuring carriage can be more easily set in motion at the start of work. According to a development of the invention, the pressure cylinders are not articulated at an angle, but rather the Y and Q forces are carried out and controlled separately. As a result, the derailment criterion and the pressing criterion can always be reliably met. According to a development of the invention, the cylinders are designed as hydraulic, electric or pneumatic cylinders. So that the derailment criterion and the compression criterion can be met, the pressures in the cylinders are measured by pressure sensors and controlled and regulated via control valves (proportional or servo valves) in such a way that the optimal forces Y, Q result.

• Fig. 1 eine Ansicht eines IMU-Messwagens von oben,
• Fig. 2 Schnitt des IMU-Messwagens aus Fig. 1,
• Fig. 3 einen vergrößerten Schnitt B-B durch ein Messrad mit Drehgeber (Encoder) für die Wegmessung aus Fig. 1 und
• Fig. 4 eine Übersicht über die Koordinaten und die Freiheitsgrade des Messwagens.
• Fig. 1 zeigt erfindungsgemäß einen Gleismesswagen 1 mit einem Trägheitsnavigationssystem 2 das auf einem Messwagenrahmen 21 angeordnet ist. Der Messwagen 1 läuft auf vier Rädern 3 auf den Schienen. Die Räder 3 einer Gleismesswagenseite sind jeweils miteinander starr verbunden und dazu auf zweiarmigen Hebeln 5, 9 gelagert. Die zweiarmigen Hebel 5, 9 beider, gegenüberliegenden Radseiten sind über eine Achse 13 miteinander verbunden und um die Achse 13 relativ zueinander verschwenkbar gelagert. Damit kann der

In the drawing, the subject of the invention is shown schematically, for example. Show it

• 1 a view of an IMU measurement van from above,
• 2 Cut out of the IMU measuring car 1 ,
• 3 shows an enlarged section BB through a measuring wheel with rotary encoder (encoder) for distance measurement 1 and
• 4 an overview of the coordinates and the degrees of freedom of the measuring carriage.
• 1 1 shows, according to the invention, a track measuring car 1 with an inertial navigation system 2 which is arranged on a measuring car frame 21. The measuring carriage 1 runs on four wheels 3 on the rails. The wheels 3 on one side of the track measuring car are each rigidly connected to one another and are mounted on two-armed levers 5, 9 for this purpose. The two-armed levers 5, 9 on both opposite wheel sides are connected to one another via an axis 13 and are mounted so as to be pivotable about the axis 13 relative to one another. With that he can

Track measuring car 1 assume a defined position in twisted tracks and the wheels 3 on both sides can follow the respective height profile of the rail unhindered.

The measuring carriage frame 21 is connected to the axle 13 via two cylinders (shown as double-acting) 10, 6. For this purpose, the measuring carriage frame 21 is also mounted on two continuous, cylindrical guides 4 over the frame width. The entire measuring carriage frame 21 is moved vertically with respect to a console 14 via two cylinders 12 acting vertically. The torsion of the left pair of wheels relative to the right pair of wheels, which are rigidly connected to the measuring frame, about the axis 13 is measured via a rotary encoder (angle encoder) 8 . The measuring frame is guided vertically by a vertical guide 7 . The carriage 1 can be rotated about the axes x, y, z, in particular with respect to the console 14, via a ball joint bearing 11. The ball joint bearing 11 is moved up and down via a sleeve sliding on the guide column 7 .

2 shows a section through the measuring carriage 1. The entire measuring carriage 1 is connected via the console 14 to the machine frame of a track-laying machine, not shown in detail. Via the vertical cylinders 12, which are articulated to the wagon and the console 14, the wagon 1 can be lowered onto a track and lifted off the track (direction V) and, during measurement runs, pressed down against the rails of the track with a specified force Qzli, Qzre. The measuring carriage frame 21 can be moved to the left or right (direction H) on the guides 4 via the double-acting pressure cylinders 6, 10 and pressed against the rail with the desired force FY. In the ball joint 11, the carriage can be rotated about the vertical axis z by the angle GW (yaw angle). The ball joint bearing 11 also allows rotations RW (roll angle) around the longitudinal axis x of the track. In addition, the carriage can also be rotated about the transverse axis y NW (pitch angle) via the ball joint 11 . This results in the necessary 5 degrees of freedom of the measuring carriage. The axis 13 of the carriage goes through the measuring carriage width.

On the left-hand side, a bearing 16 of the left-hand pair of wheels is shown in section, which can rotate relative to the right-hand pair of wheels 15 , which is firmly connected to the axis of rotation 13 . With the help of the rotary encoder 8, the angle of rotation ROT of the two pairs of wheels can be measured relative to one another. The lower part of the measuring carriage, which can be moved transversely, slides on the horizontal guides 4.

3 shows the cut BB out Fig.1 by one of the wheels designed as distance measuring wheels. All wheels 3 are designed in two parts and each comprise a wheel part 19 and a freely rotatable wheel flange part 20. So that the wheels do not slip due to the frictional forces between wheel flange and rail, wheel flange part 20 and wheel part 19 are designed to be rotatable separately from one another. In the transition to the wheel tread, the wheel flange has a smaller diameter than the wheel tread, so that no mechanical coupling between the two independently rotatable parts can occur via a rail. The wheel movements 19 are measured via a rotary encoder 18 and output in pulses. The rotary encoder 8 for measuring the torsion between the wheel pairs on the left and right about the axis 13 is in this view to the right of the wheel flange part 20.

4 gives an overview of the coordinates and the degrees of freedom used by the measuring carriage. Z is the vertical (gravity) axis. Y is the transverse axis and x points in the longitudinal direction of the track. The measuring carriage can be moved vertically V along the z-axis and horizontally H along the y-axis. The rotation around the vertical axis z is called the yaw angle GW (direction angle), the rotation around the transverse axis y is the pitch angle NW (inclination angle) and the rotation around the longitudinal axis x is the roll angle RW (elevation angle) and is recorded by the inertial navigation system 2.

In particular, pressure sensors can be assigned to the cylinders 6, 10, 12, with the pressure cylinders 6, 10 and the vertical cylinders 12 preferably being controlled and regulated via proportional valves in such a way that the ratio of the transverse force Y, which presses the wheel in the y-direction against the rail , to the vertical load Q, which presses the wheel against a rail in the z-direction, is less than or equal to 1.2 and the transverse force Y is greater than the frictional force Q µ.

Claims (6)

1. On-track measuring carriage (1) for measuring track position geometries, comprising a measuring carriage frame (21) which is arranged on a chassis and to which an inertial navigation unit (2) is allocated and which can be adjustably displaced with respect to a console (14) which can be fastened to the machine frame of a track superstructure machine, wherein actuators effect lifting and pressing movements of the measuring carriage (1), wherein the chassis is allocated, on each measuring carriage side, two wheels (3) and wherein the measuring carriage frame has five degrees of freedom and in particular a rotation about the vertical axis (z, GW) of the measuring carriage frame (21), a rotation about the longitudinal axis (x, RW) of the measuring carriage frame (21), a rotation about the transverse axis (y, NW) of the measuring carriage frame (21), a linear movement along the z-axis (V) and a linear movement of the measuring carriage frame (21) along the y-axis (H), in particular in relation to the chassis, characterised in that the wheels (3) of each measuring carriage side which are combined to form wheel pairs are each arranged on a two-armed lever (5, 9) and the levers (5, 9) are mounted so as to be pivotably adjustable about an axis (13) of the chassis passing through across the width of the measuring carriage, in that the navigation unit (2) is fixedly connected to a wheel pair in order to measure the course of this wheel pair in terms of height along the rail and in that the axis (13) is allocated a rotary encoder (8) for detecting a torsion angle (ROT) between the two levers (5, 9).
2. On-track measuring carriage (1) as claimed in claim 1, characterised in that a cylinder (12) in parallel with the vertical axis and allocated to the left measuring carriage side and a cylinder (12) in parallel with the vertical axis and allocated to the right measuring carriage side are provided for transmitting vertical forces (QZ_li, QZ_re) between the chassis and the console (14) and in that the measuring carriage frame (21) for transmitting horizontal forces in parallel with the y-axis to the chassis is guided along at least one guide (4) and can be displaced by means of pressing cylinders (6, 10) arranged between the chassis and the measuring carriage frame.
3. On-track measuring carriage (1) as claimed in claim 1 or 2, characterised in that at least one of the measuring wheels (3) is allocated a rotary encoder (18) for path measurement.
4. On-track measuring carriage (1) as claimed in any one of claims 1 to 3, characterised in that the wheels (3) each have a running wheel part (19) and a wheel flange part (20) which can be freely rotated with respect to the running wheel part (19).
5. On-track measuring carriage (1) as claimed in any one of claims 1 to 4, characterised in that, in order to detect linear movements along the vertical (V) and the horizontal (H), path sensors are provided which are integrated into the cylinders (12, 6, 10) or which are allocated to the cylinders (12, 5, 10).
6. On-track measuring carriage (1) as claimed in any one of claims 1 to 5, characterised in that the cylinders (6, 10, 12) are allocated pressure sensors, wherein the pressing cylinders (6, 10) and the vertical cylinders (12) are activated and regulated via proportional valves.

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