阅读说明：本技术 包括地面加工机和另一车辆及间距监控装置的作业牵引车 (Working tractor comprising a ground working machine, a further vehicle and a distance monitoring device ) 是由 M·弗里茨 H·兰格 M·佩斯 C·卡尼亚 于 2020-02-18 设计创作，主要内容包括：一种作业牵引车,包括以理论间距依次沿作业方向运动的自驱动第一车辆和其他的车辆,作业牵引车具有输出间距信号的间距监控装置,间距监控装置具有射束源和检测射束源辐射的传感器组件,车辆作为源车辆携带射束源,射束源朝作为目标车辆的另一车辆射出电磁辐射,使得辐射仅存在于射束空间中,该射束空间在围绕第一射束空间轴线的第一角范围和围绕第二射束空间轴线的第二角范围延伸。传感器组件沿着传感器轴线延伸并且布置在目标车辆上,通过射束源照射传感器组件上的基准检测区域,传感器轴线绕平行于第一射束空间轴线的倾斜轴线倾斜地布置,从而车辆间距的变化引起传感器组件的检测区域的位置变化并因此引起传感器组件的检测状态的变化。(A work tractor comprising a self-propelled first vehicle and a further vehicle which are sequentially moved in a work direction at a theoretical separation, the work tractor having a separation monitoring device which outputs a separation signal, the separation monitoring device having a beam source which carries the beam source as a source vehicle and a sensor assembly which detects the radiation of the beam source, the beam source emitting electromagnetic radiation towards a further vehicle as a target vehicle such that the radiation is only present in a beam space which extends over a first angular range around a first beam space axis and a second angular range around a second beam space axis. The sensor assembly extends along a sensor axis and is arranged on the target vehicle, a reference detection area on the sensor assembly is illuminated by the beam source, the sensor axis is arranged obliquely about an inclination axis parallel to the first beam space axis, so that a change in the vehicle separation causes a change in the position of the detection area of the sensor assembly and thus a change in the detection state of the sensor assembly.)

1. A work tractor (10) comprising a self-propelled ground working machine (12) as a first vehicle (12) and at least one further self-propelled vehicle (14), wherein the vehicles (12, 14) of the work tractor (10) are designed such that they are moved successively in a common working direction (A) with a theoretical spacing in a predetermined theoretical spacing value range during a defined working operation, wherein the work tractor (10) has a spacing monitoring device (26) which outputs a spacing signal as a function of a detection state of the spacing monitoring device (26), which detection state is dependent on the actual spacing (D, D ', D ") of the vehicles (12, 14), said spacing signal containing information about the vehicle spacing (D, D', D"), wherein the spacing monitoring device (26) has a beam source (28) which emits electromagnetic radiation (32) and an electromagnetic radiation source (28) A radiation (32) -sensitive sensor arrangement (30), wherein a vehicle (12) of the first vehicle (12) and the further vehicle (14) carries a beam source (18) as a source vehicle (12), wherein, when the work tractor (10) is in a predetermined reference state, i.e. the work tractor (10) has vehicles (12, 14) which are arranged on a flat horizontal foundation (U) to be prepared for work at a predetermined reference distance (D) away from one another, the beam source (28) now emits electromagnetic radiation (32) in the direction of the first vehicle (12) and a respective further vehicle (14) of the further vehicle (14) as a target vehicle (14) in such an orientation that the electromagnetic radiation (32) for distance monitoring is present only in a beam space (40) which extends over a first angular range (43) around a first beam space axis (42) and which extends around a second spatial axis (44) ) Extends over a second angular range (46) which encloses the angle of the first beam space axis (42), wherein the second angular range (46) is numerically equal to or greater than the first angular range (43), and wherein the beam space (40) is inclined about the first beam space axis (42) with respect to a working direction (A), characterized in that the sensor assembly (30) extends along a sensor axis (36) and is arranged on a target vehicle (14) for carrying by the target vehicle, wherein the beam source (28) illuminates a predetermined sensor axial reference detection region (34) on the sensor assembly (30) as seen in a reference state of the working tractor (10), and wherein with respect to a straight connection line (33) between the detection region (34) and the beam source (28), the sensor axis (36) is arranged to tilt about a tilt axis (54) parallel to the first beam space axis (42), such that a change in the vehicle separation (D, D', D ") causes a change in the position along the sensor axis (36) of a detection region (34) of the beam source (28) radiating on the sensor assembly (30), and thus a change in the detection state of the sensor assembly (30).

2. The work tractor (10) according to claim 1, characterized in that the target vehicle (14) has at least two sensor assemblies (30) extending along sensor axes (36), the sensor axes (36) of which sensor assemblies are each arranged inclined about an inclination axis (48) parallel to the first beam space axis (42) with respect to a straight line of connection (33) between the detection region (34) and the beam source (28) for the work tractor (10) in a reference state, wherein at least two sensor assemblies (30) are arranged relative to one another with a spacing in a circumferential direction about the second beam space axis (44).

3. The work tractor (10) according to claim 1 or 2, characterized in that the beam source (28) is a laser beam source (28) emitting laser light as electromagnetic radiation (32).

4. The work tractor (10) according to claim 3, characterized in that the beam source (28) emits a laser beam (32) that oscillates or rotates about the second beam spatial axis (44).

5. The work tractor (10) according to any of the preceding claims, characterized in that the first beam space axis (42) is parallel to a pitch axis (N1) of the source vehicle (12) or/and the second beam space axis (44) is in or parallel to a plane spanned by a yaw axis (G1) and a roll axis (R1) of the source vehicle (12).

6. The work tractor (10) according to claim 5, characterized in that in a Cartesian vehicle coordinate system consisting of roll, pitch and yaw axes, an extension component of a sensor axis (36) of at least one sensor assembly (30) in a plane parallel to a plane spanned by the yaw axis (G2) and the roll axis (R2) of the target vehicle (14) is greater than an extension component in a plane orthogonal thereto.

7. The work tractor (10) according to one of the preceding claims, characterized in that the source vehicle (12) or/and the target vehicle (14) has an actuator (52, 56) which is coupled in a motion-transmitting manner with the beam source (28) or with the sensor assembly (30) so that the beam source (28) or/and the at least one sensor assembly (30) is accommodated on the respective vehicle (12, 14) carrying it by means of the actuator so as to be movable relative to the respective vehicle body (12a, 14a) about an adjustment axis (50, 54) parallel to the first beam space axis (42).

8. The work tractor (10) according to one of the preceding claims, characterized in that the distance monitoring device (26) has a control device (58, 70) and the first vehicle (12) or/and the further vehicle (14) has a yaw angle detection device (74, 78) which detects a yaw angle of the respective vehicle (12, 14), wherein at least one yaw angle detection device (74, 78) transmits a yaw angle signal containing information about the yaw angle of at least one vehicle (12, 14) to the control device (58, 70), wherein the control device (58, 70) generates a distance signal depending on the condition of the detection state of at least one sensor assembly (30) and depending on the condition of the yaw angle signal of at least one yaw angle detection device (74, 78).

9. The work tractor (10) according to any one of the preceding claims, characterized in that the spacing monitoring device (26) has a control device (58, 70), and the first vehicle (12) or/and the further vehicle (14) having a pitch angle detection device (76, 80) which detects the pitch angle of the respective vehicle (12, 14), wherein at least one pitch angle detection device (76, 80) transmits a pitch angle signal containing information about the pitch angle of at least one vehicle (12, 14) to the control device (58, 70), wherein the control device (58, 70) generates a pitch signal in dependence on the condition of the detection state of the at least one sensor assembly (30) and in dependence on the condition of the pitch signal of the at least one pitch detection device (76, 80).

10. The work tractor (10) according to claim 8 or 9, characterized in that the yaw angle signal contains information about a relative yaw angle between the source vehicle (12) and the target vehicle (14) or/and the pitch angle signal contains information about a relative pitch angle between the source vehicle (12) and the target vehicle (14).

11. The work tractor (10) according to any one of the preceding claims, characterized in that the spacing signal contains operating information for operating a drive motor (62, 64) or/and a vehicle brake of at least one of the vehicles (12, 14).

12. The work tractor (10) according to any one of the preceding claims, characterized in that the vehicles (12, 14) of the work tractor (10) are in data communication connection with each other in at least one data transmission direction by means of a data communication connection.

13. The work tractor (10) according to any one of the preceding claims, characterized in that one vehicle (12, 14) of the source vehicle (12) and the target vehicle (14) predetermines a speed of movement in the work direction (a) as a lead vehicle (12) and outputs a pitch signal to the respective other vehicle (14) of the source vehicle (12) and the target vehicle (14) as a follow vehicle (14).

14. The work tractor (10) according to claim 13, characterized in that the following vehicle (14) is configured to display to the lead vehicle (12) during a prescribed work operation that an operating parameter has approached or has reached a parameter limit value thereof exceeding a predetermined alert threshold value.

15. The work tractor (10) according to claim 13 or 14, characterized in that the first vehicle (12) is a ground working machine (12) that applies material on a foundation (U) and the other vehicle (14) is a feed vehicle (14) that transfers specific material to the ground working machine (12) for applying material, wherein the ground working machine (12) is a guide vehicle (12) and the feed vehicle (14) is a following vehicle (14).

Technical Field

The invention relates to a working tractor comprising a self-propelled ground working machine as a first vehicle and at least one further self-propelled vehicle, wherein the vehicles of the working tractor are designed such that they are moved in succession in a common working direction during a predetermined working operation at a set distance in a predetermined set distance value range, wherein the working tractor has a distance monitoring device which outputs a distance signal as a function of a detection state of the distance monitoring device which is dependent on the actual distance of the vehicles, the distance signal containing information about the distance between the vehicles, wherein the distance monitoring device has a beam source which emits electromagnetic radiation and a sensor arrangement which is sensitive to the electromagnetic radiation of the beam source, wherein one of the first vehicle and the further vehicle carries the beam source as a source vehicle, wherein, in the predetermined reference state of the working tractor, the self-propelled ground working machine is moved in the common working direction in a predetermined manner, wherein the distance monitoring device outputs a distance signal as a function, I.e. on a flat horizontal ground with the vehicles which are prepared for work operation at a predetermined reference state, remote from one another, the beam source then emits electromagnetic radiation in the direction of the first vehicle and the respective other vehicle of the other vehicle as target vehicle in such an orientation that the electromagnetic radiation for distance monitoring is present only in a beam space which extends over a first angular range around a first beam space axis and over a second angular range around a second beam space axis which encloses an angle with the first beam space axis, wherein the second angular range is equal to or greater in value than the first angular range, and wherein the beam space is inclined with respect to the work direction with the first beam space axis.

Background

Such a work tractor is known from US 2018/0142427 a1, in particular from fig. 6 thereof. Among these, the ground working machine is a road paver (Stra β enferrier), hereinafter also referred to as "road builder (Fertiger)". Another vehicle is a feeder that loads the road builder with asphalt during operation of the road builder.

In the known feeder, LED light sources are arranged which emit light into the road builder in a vertically narrow beam space which has no opening angle of more than 6 ° and extends horizontally approximately over the width of the road builder.

The light of the LED light source reflected by the road builder is detected by the sensor assembly of the feeder. During the time of operation of the light from the LED source to the road construction machine and back to the sensor assembly, the value of the distance between the feeding machine and the road construction machine is calculated and a distance signal containing distance information is output on the feeding machine in order to assist the movement control of the work tractor.

A disadvantage of this working tractor is on the one hand the high costs that must be used for the distance measurement. The most orthogonal and planar surfaces on the feeder must be irradiated as far as possible from the direction of the distance between the road paver and the feeder, since the raised and retracted structures and the differently inclined surface regions on the irradiated regions of the road paver can cause undesirable signal interference or "fading" of the reflected light required for determining the running time.

On the other hand, to determine the operating time of the light, a complex modulation of the light must be emitted by the known LED light sources, so that the operating time can be completely detected.

Thus, in the case of heavily polluted construction site environments and in the case of additional thermal and alternating loads on the vehicle to which the work tractor is concerned, a less complex and therefore more robust, but ultimately equally accurate, work solution for monitoring the spacing of the vehicles of the work tractor is desired.

Disclosure of Invention

The object of the invention is therefore to improve a work tractor of the type mentioned at the outset in such a way that the distance maintained between its vehicles can be monitored by means of simple, less susceptible to interference. The spacing should also be maintained without mechanical physical coupling of the vehicles.

The invention achieves this object by means of a work tractor of the kind described in the present application, wherein additionally a sensor assembly extends along a sensor axis and is arranged on the target vehicle for being carried by the target vehicle, wherein a predetermined sensor-axial reference detection region on the sensor assembly is illuminated by the beam source, as seen in a reference state of the work tractor, and wherein the sensor axis is inclined, i.e. arranged non-parallel, with respect to a straight line of connection between the detection region and the beam source with an inclination axis parallel to the first beam-space axis, so that a change in the vehicle spacing causes a change in the position of the detection region on the sensor assembly irradiated by the beam source along the sensor axis and thus a change in the detection state of the sensor assembly. The sensor axis may, but need not, be tilted about another axis.

The electromagnetic radiation emitted by the beam source is preferably detected by the sensor arrangement in the direct beam path, i.e. without prior reflection on the vehicle surface. Starting from the reference state or from any other starting distance, a change in the distance between the vehicles of the work tractor causes the detection region of the sensor arrangement irradiated by the beam source to move along its sensor axis, based on the given tilt of the beam space and the tilt of the sensor arrangement located at least partially in the beam space in the reference state. The change is direction-sensitive, i.e., it always changes in the same direction on the sensor arrangement from the first illuminated detection region when the vehicle distance is shortened and always changes in the same opposite direction when the vehicle distance is increased.

In the once-set working tractor, the beam source irradiates a predetermined detection region of the sensor assembly in a reference state, during which preferably a dark region of the sensor assembly on at least one side of the irradiated detection region in the sensor axial direction is not irradiated, the pitch monitoring can be and preferably is carried out without numerically calculating the pitch, the distance being determined solely on the basis of the position of the irradiated detection region of the sensor assembly relative to the reference position.

The adjective "axial" with "sensor axial" relates to the sensor axis. "along the sensor axis" is synonymous.

The dark regions of the sensor arrangement are preferably arranged on both sides of the illuminated detection region in the reference state in the sensor axial direction, so that, in the event of a change in the distance, previously non-illuminated regions of the sensor arrangement can be illuminated in both directions of the detection region from the reference state, and preferably no previously illuminated regions are then illuminated again. In the reference state, the sensor arrangement therefore preferably extends completely through the beam space and projects from it on both sides in the direction of penetration, i.e. along its sensor axis.

Furthermore, it is preferred that the sensor arrangement can have a plurality of sensor elements which are sensitive to the electromagnetic radiation of the beam source in succession in the sensor axial direction, so that different sensor elements are irradiated with the electromagnetic radiation of the beam source depending on the position of the detection region in the sensor axial direction or are not irradiated when they are in the dark regions of the respective detection state.

The reference distance is preferably in the theoretical distance value range, particularly preferably with two boundaries of the distance, preferably at the same distance to the theoretical distance value range.

It is basically irrelevant for the distance to be measured, as a function of which reference points on the two vehicles of the work tractor the distance is determined, as long as the distance is always determined for a given work tractor from the same reference points.

The working direction is therefore also the pitch direction, at least in common straight travel. In this context, the two vehicles of the working tractor move locally in different spatial directions, for example, as a result of cornering or as a result of driving over a convex dome or over a depression, the working direction being, in the case of doubt, the shortest connection between the reference points for determining the distance when driving straight. The two reference points are located at the same height on the foundation, on which the two vehicles of the working tractor are moved such that the working direction extends parallel to the support plane of the foundation in a reference state, in which the working tractor stands on a flat foundation at a predetermined reference distance.

Since the foundation on which the work tractor is located can be worked at least by means of the first vehicle, there can be more than one support plane along the work tractor. This is especially true since the other vehicle may be a floor finish. When the foundation or its supporting surface is used as a reference variable, the foundation and the supporting surface defined thereby may be the foundation or the surface defined by the foundation located between the vehicles in the working direction.

In principle, the distance monitoring described above is already carried out by means of a single beam source on the source vehicle of the work tractor and a single sensor arrangement on the target vehicle. However, when the target vehicle has at least two sensor assemblies each extending along a sensor axis, more precise and more convincing information about the distance between the vehicles of the work tractor can be obtained in this case. In this case, each sensor axis of the sensor assembly is arranged obliquely with respect to a straight connecting line between the detection region and the beam source with an inclination axis parallel to the first beam space axis, seen in the reference state of the work tractor. In this case, when the distance between the source vehicle and the target vehicle changes, the detection states of a plurality of sensor assemblies, preferably all sensor assemblies, change. The at least two sensor arrangements are then preferably arranged at a distance from one another in a circumferential direction (Umfangsrichtung) around the second beam spatial axis. The expansion of the beam space along the second angular range serves to illuminate or illuminate the largest possible angular range with the radiation of the beam source, so that in the largest possible second angular range in each case one sensor assembly can be arranged on the target vehicle at positions situated relatively far apart from one another. It is therefore preferred that the second angular range is larger than the first angular range.

Since the distance between at least two sensor assemblies is as large as possible, in addition to the detection redundancy, the signals of the respective sensor assemblies can also be used to distinguish a detection state change based solely on a change in the relative orientation of the vehicles of the work tractor without an actual change in the distance from a detection state change based on an actual change in the distance. This increases the effectiveness of the distance signal of the distance monitoring device.

The electromagnetic radiation of the beam source can in principle be any radiation, provided that it can be limited to a relatively small first angular range with sufficient intensity. Such first angular extent is preferably no greater than 3 ° with respect to the first beam spatial axis. The laser beam source emits electromagnetic radiation which is available approximately and at the same time highly precisely as a laser because of the local strictness. Therefore, a laser beam source is preferable as the beam source described above. The laser beam source can emit coherent light over several tens of meters, and thus can generate only one light spot over several tens of meters. In this case, the theoretical spacing value range usually does not exceed or, in the rare case, exceeds a spacing value of 20 meters in the clear width between the work tractor vehicles.

Preferably, the first angular range is limited only to the extension of the laser beam, the laser beam source emitting the laser beam as the preferred beam source. In this case, the first angular range is significantly less than 3 °.

In order to sweep the largest possible range on the target vehicle, a second angular range can be generated by targeted orientation of the laser beam emitted by the beam source or of the emitted electromagnetic radiation. For this purpose, the beam source can emit a laser beam which oscillates or rotates about a second beam spatial axis. The rotating laser beam can be shielded for work protection reasons over a large range (Umfangsbereichen) around the second beam spatial axis, wherein the target vehicle is reliably not irradiated, so that the persons working on the construction site around the work tractor are protected from the electromagnetic radiation, in particular the laser beam.

While many vehicles have a greater height than width, or in other words: has a greater extension along its yaw axis than along its pitch axis. However, it is not desirable to arrange sensitive sensor assemblies near the foundation during ground processing. Preferably, the sensor group is disposed remotely from the base station on the target vehicle. This also applies to the case where more than one sensor assembly is provided on the target vehicle. This can be achieved by arranging one sensor assembly, in particular a plurality of sensor assemblies, at a distance from the ground of the target vehicle in a direction parallel to the yaw axis, with the first beam space axis parallel to the pitch axis of the source vehicle, or/and the second beam space axis in or parallel to a plane spanned by the yaw axis and the roll axis of the source vehicle, while at least one sensor assembly has a great degree of freedom of arrangement on the target vehicle in a direction parallel to the pitch axis.

Here, the second beam space axis may be parallel to the yaw axis; the laser shots emitted by the preferably rotating or oscillating laser beam source now appear as conical or partially conical caps. Or the second beam space axis is inclined relative to the yaw axis and relative to the roll axis, the beam space may then particularly preferably be a plane spanned by the laser beam or, in the case of laser beam oscillation, may be a flat fan. The term "plane" should not be understood in a purely mathematical sense for this purpose. The plane described here has an extent orthogonal to its flat face, which corresponds to the thickness of the laser beam. Advantageously, a change in the detection state can be reliably detected when the sensor axis of the at least one sensor arrangement has a greater extension component in a cartesian vehicle coordinate system formed by the roll axis, pitch axis and yaw axis in a plane parallel to a plane spanned by the yaw axis and roll axis of the target vehicle than in a plane orthogonal thereto.

Preferably, the sensor arrangement is parallel to a plane spanned by the yaw axis and the roll axis of the target vehicle. Additionally or alternatively, at least one sensor assembly, preferably each sensor assembly, may be oriented with its sensor axis orthogonal to the line of separation between the sensor assembly and the beam source. In this case, the sensor arrangement has a high sensitivity with a change in the distance with the same sensing range.

In order to simplify the adjustment of the distance monitoring device, the beam source and/or preferably at least one sensor assembly is preferably arranged on the source vehicle or on the target vehicle so as to be movable relative to the body of the vehicle which respectively carries it.

It is sometimes necessary to change the theoretical distance or/and the theoretical distance value range between the source vehicle and the target vehicle during a work operation, for example because one of the two vehicles, which are composed of the source vehicle and the target vehicle, is replaced by a vehicle which has the same function but is constructed differently in terms of structure. In this case, it is advantageous if the respective vehicle driver or the single vehicle driver does not have to leave his cab to set the distance monitoring device to a new operating situation in the case of automated distance control. For this purpose, according to an advantageous development of the invention, it can be provided that the source vehicle has a source actuator, or/and the target vehicle has a sensor actuator, wherein the source actuator is coupled in a motion-transmitting manner to the beam source, or/and the sensor actuator is coupled in a motion-transmitting manner to the sensor assembly, so that the beam source or/and at least one sensor assembly is accommodated on the vehicle respectively carrying it by the actuator so as to be movable relative to the respective vehicle body about an adjustment axis parallel to the first beam space axis. One or both of the actuators may additionally be movable about a further adjustment axis.

In the present application, the work tractor is operated in a reference state, i.e. the two vehicles of the work tractor are located one after the other in the work direction on a flat horizontal foundation, if not stated to the contrary. Their yaw axes are parallel and their pitch axes are also parallel. The roll axes of the two vehicles extending parallel to the working direction are parallel or collinear in the reference state.

Depending on the installation position of the beam source and the sensor arrangement, a change in the operating state of the working tractor starting from a reference state, for example due to the working tractor turning around, can cause a change in the detection state of the distance monitoring device, but the distance between the vehicles of the working tractor does not change in practice. In order to reduce the probability of a false detection or a false determination of the detection state of the distance monitoring device, it can be provided according to a further development of the invention that the distance monitoring device has a control device and the first vehicle or/and the further vehicle has a yaw angle detection device which detects the yaw angle of the respective vehicle, wherein at least one yaw angle detection device transmits a yaw angle signal containing information about the yaw angle of at least one vehicle to the control device, wherein the control device generates a distance signal depending on the state of the detection state of at least one sensor arrangement and depending on the state of the yaw angle signal of at least one yaw angle detection device.

The yaw angle detection device can detect information about the yaw angle of at least one vehicle in any desired manner, for example by means of a GPS system or by means of corresponding sensors, for example also used in mobile telephones, for determining the spatial orientation thereof. In addition or instead of a yaw angle sensor which directly detects the yaw angle, the yaw angle of a vehicle can be detected indirectly by detecting the yaw angle and the route traveled by the vehicle or/and the vehicle speed over a common time period.

Preferably, each vehicle of the working tractor has a yaw angle detection device, so that the relative yaw angle of the two vehicles with respect to each other can be detected directly and accurately by data communication between the two vehicles.

But it is also possible that a vehicle has a yaw angle detection device. The vehicle is preferably a vehicle that is moving ahead in the working direction. The working tractor starts its working operation in a reference state or in a defined known state with a known relative orientation of the vehicles of the working tractor with respect to one another, at least one vehicle of the working tractor, preferably again a vehicle leading in the working direction, being able to determine the time difference or/and the position difference between the change in the yaw angle of the leading vehicle and the following vehicle, depending on the travel speed of the vehicle leading in the working direction and depending on the spacing information from the spacing monitoring device, under the assumption that the yaw angle of the following vehicle changes locally along the working section in the same way as the yaw angle of the leading vehicle. This time and/or position difference can be taken into account by the control device in the evaluation of the detection state in order to generate a distance signal.

The control device advantageously has an input means by means of which data can be input into the control device and thus into the distance monitoring device. The input mechanism may include a keyboard, mouse, touch screen, microphone, etc. The distance value provided for the reference distance can be input by means of the input device, for example, in a predetermined or selectable measuring unit, so that the yaw angle change between the two vehicles of the working tractor can be calculated from the speed information of the vehicles and from the distance value of the time or/and position difference.

It is also possible to input into the control device via an input means which distance change between the vehicles corresponds to a predetermined change in the detection range of the electromagnetic radiation at the sensor arrangement. This information can also be stored in the data memory of the control device when the orientation of the sensor assembly and the beam source is fixed. In order that the orientation of the sensor assembly and the beam source can be determined from the possible positions of the source actuator or/and the sensor actuator, this information can also be determined taking into account the data for the different orientations stored in the data memory.

The relative change in the orientation of the vehicle starting from the reference state during cornering about a change axis parallel to the yaw axis can also or alternatively be adapted to the relative change in the orientation of the two vehicles about a change axis parallel to the pitch axis during cornering when driving over a dome arch or when driving over a depression in a section. To this end, according to an advantageous development of the invention, it can be provided for the detection accuracy to be increased that the distance monitoring device has a control device and the first vehicle or/and the further vehicle has a pitch angle detection device which detects the pitch angle of the respective vehicle, wherein at least one pitch angle detection device transmits a pitch angle signal containing information about the pitch angle of at least one vehicle to the control device, wherein the control device generates the distance signal as a function of the detected state of the at least one sensor arrangement and as a function of the pitch angle signal of the at least one pitch angle detection device.

The above described corrections, which are necessary for the yaw angle detection device, are applied to the pitch angle detection device by taking into account the replacement of the yaw angle by the pitch angle and, correspondingly, the replacement of the yaw axis by the pitch axis.

In the case of the above-described preferred embodiment, in which a plurality of sensor arrangements are provided on the target vehicle, the sensor arrangements being arranged on the target vehicle at a distance from one another in the tangential direction about the yaw axis of the source vehicle, the detection states of at least two sensor arrangements change in opposite directions when the relative speed of the two vehicles of the work tractor changes, when the two sensor arrangements are arranged on different sides of a vertical longitudinal plane through the beam source parallel to the roll axis and the yaw axis of the target vehicle. And the detection state of the sensor assembly changes in the same direction when the relative pitch angle changes. Although it has been found above that it is sufficient for the yaw angle signal or/and the pitch angle signal to contain only information about one yaw angle or pitch angle of the vehicle with the respective detection device, it is advantageous in order to avoid detection errors as comprehensively and accurately as possible that the yaw angle signal contains information about the relative yaw angle between the source vehicle and the target vehicle or/and the pitch angle signal contains information about the relative pitch angle between the source vehicle and the target vehicle.

Instead of or in addition to arranging at least two sensor assemblies on different sides of said vertical longitudinal plane, the change in the sensed condition caused by a change in the relative yaw angle may be distinguished from the change in the sensed condition caused by a change in the relative pitch angle by at least two sensor assemblies on substantially the same roll axis position, the sensor assemblies being arranged on the same side of the vertical longitudinal plane but at different spacings therefrom. The change in the relative yaw angle causes an increasing change in the value of the detected state as the spacing from the vertical longitudinal plane increases. And this does not apply to changes in relative pitch angle.

The distance signal is advantageously used such that the distance between the vehicles of the work tractor remains in a predetermined setpoint distance value range during the work operation. In the theoretical pitch value range, a defined work operation is usually reliably achieved. For this purpose, it can be provided that the distance signal contains operating information for operating the drive motor and/or a vehicle brake of at least one of the vehicles.

The operating information may be information output to a vehicle driver of at least one vehicle to slow down or accelerate or not change the speed of its vehicle. However, the operating information can also be directly control information for controlling the vehicle, so that one of the vehicles is automatically decelerated or accelerated, i.e. without intervention of an operator, or/and a specific driving speed is set. The purpose of this control or regulation can be to maintain the detection region of the sensor arrangement in a predetermined detection region or, if necessary, to return it. The detection area is defined by a spacing interval corresponding to a predetermined theoretical spacing value range.

According to an advantageous further development of the invention, historical information about the change in the detection state and/or about the detection state during its time course can be stored in the data memory. The data storage device can be queried by a control device, preferably a control device of the distance monitoring device. In this way, when the sensor arrangement no longer detects the radiation of the beam source, i.e. when the sensor arrangement is outside the beam space due to an excessively large value of the distance change, operating information can be output which is used to establish the operating state of the distance of the vehicle having the work tractor in the theoretical distance value range. It is then also possible to derive from the history information stored in the data memory device, in the absence of a detection signal at the sensor element, in which direction the detection region leaves the sensor element. From this direction it can be determined whether one of the vehicles has to be accelerated or decelerated in order to change the currently existing distance to a distance in the theoretical distance value field.

Since the vehicles of the work tractor work independently of one another and, for example, have operating limits which need to be complied with in order to carry out a work operation, it is advantageous if the vehicles of the work tractor are connected to one another in a data communication manner, preferably bidirectionally, by means of a data communication connection in at least one data transmission direction.

Thus, for example, one of the two vehicles can inform the respective other vehicle via the data communication connection that it has reached the limit operating speed and can no longer accelerate or decelerate. This can be helpful precisely for automatically adjusting the spacing between the vehicles of the vehicle tractors. In order to limit the guidance of the work tractor in the work direction as far as possible, it is further advantageous if one of the source vehicle and the target vehicle, as a guidance vehicle, specifies a movement speed of the work tractor in the work direction in advance, and outputs a distance signal to the respective other one of the source vehicle and the target vehicle, as a following vehicle. In this case, such a vehicle is usually a lead vehicle or a host vehicle, the influence of a change in an operating parameter of which on the work result is more important than a change in an operating parameter of a respective other vehicle which is then logically a following vehicle.

In a further refinement of the display of the reaching of the limit operating parameter, it can be provided that the following vehicle is configured to display for the guiding vehicle during the prescribed work operation that the operating parameter has approached or has reached its parameter limit value above a predetermined warning threshold value.

In a preferred embodiment, the first vehicle is a ground working machine which applies the material on the foundation and the further vehicle is a supply vehicle which transfers the specific material to the first vehicle for applying the material. The ground working machine, usually a road paver, which applies material to the ground is here a guide vehicle, since changes in the operating parameters of this vehicle directly influence the quality of the ground produced, for example the flatness, or the degrees of freedom of the elevations and depressions. Since changes in the operating parameters of the feed vehicle have a minor influence on the work result of the work tractor, the feed vehicle is now the following vehicle. The supply vehicle may be a feeder or may be a transport wagon or may be a regenerating machine which strips off the foundation directly before the paver as the lead vehicle, prepares the stripped material and transfers it to the paver for reconstruction.

The basic rule may be that, in view of observing the overall desired work result of the work tractor, the ground working machine which directly influences the work result in terms of structure is preferably a lead vehicle and, even if the other vehicle of the work tractor is also a ground working machine, is a following vehicle when it does not contribute directly, but only indirectly, to the work result of the work tractor.

The above-described control device of the distance monitoring device is preferably arranged on the following vehicle, so that the distance signal of the distance monitoring device is present directly on the vehicle whose distance signal is to influence the control. The lead vehicle can then work with the respective optimum operating parameters for a given work task, and the following vehicle is aligned with the lead vehicle.

In a preferred embodiment, the distance signal on the following vehicle is used directly for controlling the speed as a function of the following vehicle in order to maintain the preset target distance between the vehicles within the preset target distance range as precisely as possible.

Since the distance signal is derived on the basis of the detection state of the sensor arrangement, the sensor arrangement is preferably also arranged on the following vehicle, whereas the beam source is preferably arranged on the guide vehicle. In which case data communication between the lead vehicle and the following vehicle can be minimized. Only when the following vehicle, for example a regenerator, has reached its maximum speed, it is advantageous if the following vehicle displays this for the guiding vehicle, so that the guiding vehicle does not increase its speed further, although this is possible according to the basic circumstances of the respective construction site.

It is therefore preferred that the source vehicle is a lead vehicle and the target vehicle is preferably a follow-up vehicle.

It should be clear that the following vehicle need not be after the lead vehicle. In the preferred example of a road paver as the ground working machine of the first vehicle, the following vehicle usually leads the vehicle in the working direction.

Drawings

The invention is explained in detail below with reference to the drawings. In which is shown:

fig. 1 shows a rough schematic side view of a work tractor according to the invention, wherein the two vehicles of the work tractor are at a reference distance,

fig. 2 shows a rough schematic side view of the work tractor of fig. 1, wherein the distance between the two vehicles of the work tractor is increased,

fig. 3 shows a rough schematic side view of the work tractor of fig. 1, wherein the distance between the two vehicles of the work tractor is reduced,

fig. 4 shows a rough schematic side view of fig. 1, in which the foundation dome is arched,

fig. 5 shows a rough schematic top view of the work tractor in the reference state of fig. 1, an

Fig. 6 shows the work tractor of fig. 5 after driving into a right-hand bend.

Detailed Description

An embodiment according to the invention of a work tractor according to the present application is indicated generally at 10 in fig. 1 to 6. The work tractor 10 includes a first vehicle 12 and another vehicle 14. The first vehicle 12 is, for example, a road paver and the other vehicle 14 is a reclaimer. Thus, the two vehicles 12 and 14 are ground working machines.

The work tractor 10 moves in a working direction a, which is parallel to the plane of the drawing of fig. 1 to 4. Because the vehicles 12 and 14 are ground vehicles, the work direction A is also parallel to the foundation U on which the vehicles 12 and 14 are located.

The other vehicle 14, for example a reclaimer, strips material from the ground with a working device 16 comprising milling rollers and prepares the stripped ground material by mixing in an adhesive, so that the reclaimed ground material 17 is transported from the other vehicle 14 via a conveyor belt 18 into a hopper 20 of the first vehicle 12.

The material in the hopper 20 is built into a firm ground layer by the road builder 12.

The regenerator 14, which is located in front of the road builder 12 in the working direction a, works destructively on the ground as described. The foundation U is prepared for the laying construction of the road builder 12 by the reclaimer 14. The road builder 12 works constructively and directly builds the desired working effect of the working tractor 10.

Since the foundation has locally different surface planes in the application example, the foundation U between the two vehicles 12 and 14 in the working direction a can be used as a reference foundation, which forms a uniform reference surface and reference plane for the two vehicles 12 and 14.

The vehicles 12 and 14 have a distance D from each other in the working direction a in the reference state shown in fig. 1.

Since the road construction machine 12 directly influences the operational effect of the work tractor 10, whereas a change of the operating parameters of the regeneration machine 14 only indirectly influences the operational effect of the work tractor 10, the road construction machine 12, i.e. the first vehicle 12, is in this example a guide vehicle, which primarily presets the speed of the work tractor 10. The regenerator 14 is accordingly a following vehicle whose speed in the working direction a is within predetermined limits depending on the presettings of the lead vehicle 12.

The cab 22 of the road construction machine 12 is assigned to an operator. The cab 24 of the regenerator 14 may be assigned to an operator, and this is also typically for reasons of operational safety. As will be explained in more detail below, however, the feed speed of the regenerator 14 in the working direction a can be automatically controlled at least as a function of the feed speed of the road builder 12 and the inter-vehicle distance interval that must be maintained between the vehicles 12 and 14.

The vehicle distance D should lie within predetermined limits in a predetermined setpoint distance value range, so that, for example, the reclaimed ground material 17 thrown off the conveyor belt 18 reliably reaches only the hopper 20 of the road construction machine 12. The conveying device for conveying the reclaimed ground material 17 from the reclaimer 14 to the road paver 12 may be realized by a further conveying means which is different from the conveyor belt conveying mechanism which is only shown schematically in fig. 1 to 6.

In order to monitor the vehicle distance D, the work tractor 10 has a distance monitoring device 26.

The spacing monitoring device includes a laser beam source 28 and two sensor assemblies 30 arranged with a spacing from each other along a pitch axis N2 of the regenerator 14. Only the sensor assembly 30 is shown in fig. 1 to 4, respectively, close to the observer. The other sensor assembly 30 located behind it is blocked by the display.

The laser beam source 28 emits a laser beam 32 which reaches the sensor device 30 only in a central detection region 34 with the reference spacing shown in fig. 1.

The sensor device 30 extends along a sensor axis 36 and has a plurality of sensor elements sensitive to the light of the laser beam 32 in succession to one another along the sensor axis 36. For example, fig. 1 shows only sensor elements 38 located in detection region 34.

The laser beam source 28 is a laser level which can be shielded from light in unnecessary radiation regions for operational safety reasons, or the laser beam source 28 is the source of an oscillating laser beam 32 which illuminates only a predetermined angular range (see second angular range 46 in fig. 5).

From the laser beam source 28, only one beam space 40 is filled with the laser beam 32, which extends around a first beam space axis 42, which is orthogonal to the drawing plane of fig. 1 to 4, over a very small first angular range 43, which corresponds substantially only to the thickness of the laser beam 32. The laser beam 32 covers a second angular range 46 about the second beam spatial axis 44, which second angular range 46 is very large compared to the first angular range 43 about the first beam spatial axis 42 (see fig. 5 and 6). The second angular range 46 is so large that the laser beam 32 reliably reaches the two sensor arrangements 30 of the regenerator 14 over the entire range of the theoretical distance value of the vehicle distance D. The second angular range 46 is only shown here in a rough schematic way in fig. 5 and 6.

The first beam space axis 42 is parallel to the pitch axis N1 of the grader 12. The second beam space axis 44 is parallel to a plane spanned by the yaw axis G1 and the roll axis R1 of the grader 12.

As shown in fig. 1, the beam space 40 about a first beam space axis 42 is inclined with respect to the working direction a. The sensor axis 36 is also tilted with respect to a tilt axis 48 that is preferably parallel to the first beam space axis 42. The sensor axis 36 extends parallel to a plane spanned by the yaw axis G2 and the roll axis R2 of the regenerator 14. Preferably, the sensor arrangement 30 is tilted about the tilt axis 48 such that the sensor axis 36 is perpendicular to the laser beam 32 impinging on the sensor arrangement 30 in the reference state shown in fig. 1. Since in the preferred embodiment shown the laser beam 32 radiates orthogonally to the second beam space axis 44, it is preferred in this embodiment that the sensor axis 36 and the second beam space axis 44 are parallel to each other. This arrangement makes it possible to achieve a large sensitivity of the sensor arrangement 30 with respect to changes in the vehicle distance D while the sensing range is large.

In fig. 5, a straight connecting line 33 is shown between the laser source 28 and the detection region 34 of the sensor arrangement 30 shown in fig. 1. In the side views of fig. 1 to 3, the representation of the connecting straight line 33 is identical to the representation of the first angular range 43 and to the representation of the laser beam 32.

Preferably, the sensor axis 36 is parallel to a sectional straight line of a plane orthogonal to the connecting straight line 33 and parallel to a plane containing the roll axis R2 and the yaw axis G2 of the other vehicle 14 in the reference state. The sensor axis then extends orthogonally to the connecting straight line 33 and is therefore tilted only about the tilting axis 48 parallel to the pitch axis N2 of the other vehicle 14.

In order to simplify the arrangement of the distance monitoring device 26, the laser beam source 28 can be adjusted on the body 12a of the road construction machine 12 about the adjustment axis 50 of the road construction machine side by means of an actuator 52, preferably an electric motor. In this example, the adjustment axis 50 of the road builder side is parallel to the first beam space axis 42 and also parallel to the pitch axis N1 of the first vehicle 12 (road builder).

To arrange the sensor arrangement 30 as well, it is provided that the sensor arrangement is oriented by means of a preferably electric motor-type actuator 56 about a regenerator-side adjustment axis 54 relative to the body 14a of the other vehicle 14. The regenerator side adjustment axis 54 is parallel to the pitch axis N2 of the regenerator 14 and also parallel to the tilt axis 48 of the sensor assembly 30.

To show the orientation of the first vehicle 12 and the further vehicle 14 in the reference state, three cartesian coordinate axes are shown on the respective vehicle by the following coordinate axes which are suitable for the vehicle: roll axis R, pitch axis N, and yaw axis G. The axis of the first vehicle 12 additionally has the number 1 and the corresponding coordinate axis of the second vehicle 14 additionally has the number 2. The yaw axes G1 and G2 of the first and second vehicles 12 and 14 are parallel to each other as are the pitch axes N1 and N2 and the roll axes R1 and R2.

The distance monitoring device 26 has a control device 58, which is arranged, for example, on the regeneration machine 14, which not only follows the vehicle, but is also the target vehicle, since the sensor arrangement 30 is arranged thereon.

Regardless of where the laser beam 32 impinges on the sensor assembly 30, the control device 58 may output a spacing signal that includes information about the vehicle spacing D. In a simple case, the distance signal can be displayed as operating information via a data line on a display device 60 in the cab 24 of the regeneration machine 14. For example, the machine driver in cab 24 can be shown, by means of display device 60, that he should accelerate the regenerator 14 in the working direction a if the vehicle distance D is too small, that he should decelerate the regenerator in the working direction if the vehicle distance D is too large, or that the vehicle speed is not changed if the vehicle distance D is suitable.

Alternatively, control device 58 may output a spacing signal to traction motors 62 and 64 of regenerator 14 and cause the traction motors to accelerate or decelerate or continue to operate at the existing drive speed based on the sensed condition of sensor assembly 30. The output of the spacing signal to the traction motors 62 and 64 is equal to the output through the control device 58 to a motor control device or central control device, which is separately constructed and arranged and controls the output of the traction motors 62 and 64. The control device 58 may also be a central control device of the regenerator 14.

In this way, the distance is monitored in the simplest manner by the distance monitoring device 26. Such a distance monitoring of the vehicle distance D is particularly advantageous without any data communication between the first vehicle 12 and the second vehicle 14. It is thus possible to implement pitch control or pitch regulation only in the following vehicle (here the regenerator 14) without any feedback for this purpose to the lead vehicle (here: the road construction machine 12).

The speed of the regenerator 14 in the working direction a is implemented such that the detection area 34 on the sensor assembly 30 is located in a predetermined sensor axial detection area.

But such communication should not be excluded.

Although the work tractor 10 operates in the manner described above with the aid of the spacing monitoring device 26, its function can be extended. The following vehicle and the target vehicle 14 thus have a transmission/reception unit 66, which can likewise be controlled via the control device 58. The transmit/receive unit 66 is used to exchange data with the transmit/receive unit 68 of the source vehicle and the lead vehicle 12.

A control device 70 can likewise be provided on the road construction machine 12, by means of which the transmission/reception unit 68 on the road construction machine side can be actuated. Furthermore, the control device 70 of the road construction machine 12 can have a data output unit 72, by means of which data, in particular display data, can be output to an operator in the cab 22.

The two vehicles 12 and 14 can exchange data between them by means of the transmitting/receiving units 66 and 68. The data communication may be unidirectional, but is preferably bidirectional. Where the data communication is unidirectional, the communication is preferably from the following vehicle 14 to the lead vehicle 12.

To improve the accuracy of the spacing monitoring, the regenerator 14 may have a yaw angle sensor 74 and a pitch angle sensor 76. Both sensors are connected to a control device 58 of the road construction machine 14 in a data-transmitting manner.

The road construction machine 12 can also have a yaw angle sensor 78 and a pitch angle sensor 80 as a guide vehicle, which are likewise connected to its control device 70 in a data-transmitting manner.

In fig. 2, the work tractor 10 of fig. 1 is shown with an increased vehicle separation distance D'. It can be seen that the detection region 34' on the sensor arrangement 30, which detects the laser beam 32 of the source vehicle 12, is displaced from the initially central detection region 34 toward the upper longitudinal end relative to the sensor axis 36. The laser light thus no longer enters the central sensor element 38, but only the upper sensor element 38'.

Without any communication between the two vehicles 12 and 14, the control unit 58 can only recognize that the vehicle distance D has changed from the reference distance of fig. 1 on the basis of the relative movement of the detection region 34 to 34'. In addition, it can be stored in the data memory of the control device 58 that the movement of the detection region 34 from the detection region 34 at the center to the detection region 34' at the upper end in the sensor axial direction means an increase in the vehicle pitch. Accordingly, control device 58 may indicate in display device 60 in cab 24 of regenerator 14 that the speed of following vehicle 14 should be reduced, or/and directly control traction motors 62 and 64 in such a way that the travel speed of regenerator 14 in work direction a is reduced.

In fig. 3, the work tractor 10 of fig. 1 is shown with a reduced vehicle separation distance D ". The detection region 34 ″ of the sensor arrangement 40 for receiving the laser beam 32 is then located at the lower end of the sensor arrangement 30 in the axial direction of the sensor. The sensor element 38 ″ on the lower end side now receives the laser light, while the laser light of the laser beam source 28 does not reach the remaining sensor elements of the sensor arrangement 30 and the remaining sensor elements are in the dark space.

From the above description of fig. 2, the control device 58 recognizes from the position of the detection region 34 "that the distance D" between the vehicles 12 and 14 has decreased or even reached the lower limit value. Accordingly, control device 58 may output a signal on a display device 60 in cab 24 that requests the operator in cab 24 to accelerate the regenerator 14 in the work direction a, or/and control device 58 may operate traction motors 62 and 64 of the regenerator 14 in a manner that increases the speed.

When the regenerator 14 has reached its maximum travel speed in the working direction a, which is also the feed speed of the working device 16, further acceleration of the regenerator 14 is no longer technically possible. In this case, the control device 58 transmits a corresponding signal via the transmitter/receiver unit 66 to the transmitter/receiver unit 68 of the road construction machine 12, where the control device 70 indicates to the machine driver in the cab 22 on the data output unit 72 that the road construction machine 12 is not permitted to complete more quickly, or even that its working speed in the working direction a should be reduced. Since the regenerator 14 is a following vehicle and its speed in the working direction a depends on the speed of the road building machine 12 in the working direction a, when the regenerator 14 reaches its maximum speed in the working direction a and the distance D between the vehicles 12 and 14 is further reduced, it can be increased again at this time also by a control intervention on the road building machine 12.

Fig. 4 shows a schematic view of the work tractor 12 of fig. 1 during driving over a vault section. The foundation U is arched with respect to a bending axis orthogonal to the plane of drawing of fig. 4.

The schematic diagram of fig. 4 shows that a change in the detection state of the sensor assembly 36 corresponds to an increase in the vehicle interval D, regardless of whether the vehicle interval D actually changes.

The stacked arrangement of the two vehicle-specific coordinate systems shown at the upper middle of fig. 4 shows that the pitch axes N1 and N2 of the vehicles 12 and 14 are always parallel to each other, but that the yaw axis and the roll axis are arranged at an angle γ to each other with respect to each other about an axis parallel to the pitch axis or the bending axis.

The control device 58 on the regenerator 14 may detect by means of a pitch angle sensor 76 that the pitch angle of the regenerator 14 changes in an absolute coordinate system. Thus, based on the travel speed of the reproduction machine 14 in the working direction a, which is known to the control device 58, the control device 58 can derive when the road construction machine 12 also follows the same orientation change with respect to its pitch axis N1. The control device 58 can thus recognize on the basis of the pitch angle signal of the pitch angle sensor 76 that the change in the detected state at the sensor arrangement 30 is not based on a change in the vehicle distance D, but on a change in the relative orientation of the two vehicles 12 and 14 about a change axis parallel to the pitch axis, wherein the control device 58 can be pre-calculated by means of a time measurement and by means of a speed measurement of the regeneration machine 14 when the coordinate system of the two vehicles 12 and 14 again has three spatial axes parallel to one another. The control device 58 of the regeneration machine 14 can thus determine, without data exchange with the road construction machine 12, whether the displacement of the detection region 34 along the sensor axis 36 is based on a distance change or on the field information. This is based on the situation where the two vehicles 12 and 14 travel the same road section with a time difference to each other.

However, in addition, a pitch angle sensor 80 can also be used on the road construction machine 12, wherein the pitch angle signal can be transmitted via the transmitting/receiving unit 68 to the transmitting/receiving unit 66 of the regeneration machine 14. From the pitch angle information of the two vehicles 12 and 14, the control device 58 can calculate the relative pitch angle of the two vehicles 12 and 14 with respect to one another and can thus directly determine whether the two coordinate systems are rotating relative to one another about their pitch axes N1 or N2. The detection result of the sensor assembly 30 can be evaluated with higher accuracy.

Fig. 5 shows the work tractor 10 of fig. 1 from above in a plan view. The second sensor arrangement 30 can be seen here, but it corresponds exactly to the sensor arrangement 30 described so far. The components and component parts that are identical and function identically to the already explained sensor arrangement 30, i.e. the lower sensor arrangement 30 in fig. 5, also correspond to the upper, second sensor arrangement in fig. 5 and 6. The references to sensor assemblies 30 apply to both sensor assemblies 30.

The dashed line segment shows the detection regions 34 on both sensor assemblies 30 when driving straight.

Since the milling rollers in the regenerator 14 are usually not arranged symmetrically in the direction of the pitch axis on the regenerator, the two vehicles 12 and 14 have a misalignment in the direction of the pitch axis in the direction of the parallel roll axis R1 or R2 in their reference state.

Fig. 5 shows that the detection regions 34 of the two sensor arrangements 30 are located, for example, in the same sensor axial region during straight travel.

In fig. 6 it is exemplarily shown that the working tractor starts to turn along a right-hand bend. The regenerator 14 has been turned into the right hand turn and the grader 12 has not been turned into. Accordingly, the detection regions of the two sensor assemblies 30 are moved along the respective sensor axes 36 without a change in the vehicle state between the vehicles 12 and 14. As the beam space 40 tilts, the vehicles 12 and 14 are offset in a counterclockwise direction at different yaw angles about the first beam space axis 42 that is parallel to the pitch axis N1 of the grader 12. In the example shown, the detection region 34 of the sensor arrangement 30 in the upper part of fig. 6 is shifted from the state in fig. 5 toward the upper longitudinal end of the sensor arrangement 30, i.e. in the direction of the detection region 34' in fig. 2. The detection region 34 of the lower sensor arrangement 30 in fig. 6 is likewise shifted from the state in fig. 5 toward the lower longitudinal end of the sensor arrangement 30, which is in the direction of the detection region 34 ″ in fig. 3.

This detection state can in principle have two reasons: on the one hand, the cornering manoeuvre shown in fig. 6 and, on the other hand, a section shape, in which the two vehicles 12 and 14 are rotated relative to each other about an axis parallel to their two initially parallel roll axes R1, R2.

However, with the yaw angle sensor 74 in the regenerator 14, based on the yaw angle signal provided by the yaw angle sensor, the control device 58 may determine that either of the sensed conditions with respect to the change from fig. 5 is based on a change in the yaw angle of the regenerator 14 and not on a change in pitch or based on rotation about the roll axis. Instead of or in addition to the yaw angle sensor 74 or 78, a roll angle sensor may be provided on one or both of the vehicles 12 and 14. However, the arrangement of the yaw angle sensor is preferred because cornering shows a significantly more common operating situation than driving around a lane that is twisted in the working direction.

Instead of yaw angle and roll angle sensors, equivalent information in terms of their effectiveness can alternatively or additionally be obtained by detecting mechanical data and evaluating them over a common period of time, for example by detecting the steering angle, the vehicle speed and time and/or the travel path, the position of a single lifting column, from which the distance of the respective vehicle body from the chassis connected to the lifting column and from the bearing surface of the ground region on which the respective chassis is located can be derived.

If only one sensor assembly 30 is arranged on the reproduction machine 14, the control device 58 can detect only a change in the detection state at the start of cornering, and cannot distinguish a change in the pitch without additional information. But since the second sensor assembly is spaced along the pitch axis N2 from a different side of the plane parallel to the roll and yaw axes of the regenerator 14 (which passes through the beam source 28 in the reference state of the work tractor), the cornering travel may cause an opposite sensing change of the above-described detection state, and thus the cornering travel is identified at the sensor assembly 30. Rather, a curve is recognizable by the additional information of the yaw angle sensor 74.

As explained above in connection with driving over a vault (see fig. 4), the yaw angle information of the yaw angle sensor 78 on the road construction machine side can also be transmitted from the road construction machine 12 to the regeneration machine 14, and in this case, together with the yaw angle information of the yaw angle sensor 74, can be converted by the control device 58 into the relative yaw angle information of the two vehicles 12 and 14 relative to one another. This provides the most accurate solution for determining the detection state of the at least one sensor assembly 30 when the vehicle separation distance D changes.