Method for operating a system comprising a vehicle and system for carrying out such a method

Abstract

The invention relates to a method for operating a system comprising a vehicle and to a system for carrying out the method, in which the vehicle travels in the system along a trajectory curve by means of a front wheel driven by a first drive operating in a rotational speed-controlled manner and a rear wheel driven by a second drive operating in a rotational speed-controlled manner, wherein the track curve has a linear region and at least one curved region, in particular a predetermined target value is generated in such a way that the actual position of the vehicle is adjusted in the direction of the target position, a target rotational speed is predefined for the first drive, the target rotational speed is determined by a first correction value added to the predetermined target value, and the target rotational speed is determined by a second correction value added to the predetermined target value. A first correction value is provided via a first path of the load compensation controller in such a way that the direction of a predefined torque distribution between the first drive and the second drive is adjusted, one of the paths of the load compensation controller being cut off after the front wheel is detected to enter the curved region.

Description

Field of the Invention

[0001] The present invention relates to a method for operating a system including a transport vehicle and a system for performing such a method. Background Art

[0002] A method for guiding a curve-running rack manipulator through a bend is known from EP 0 997 430 B1.

[0003] A curve-running rack manipulator is known from EP 2 736 832 B1, in which the torque of the front wheels is compared with the torque of the rear wheels.

[0004] As the latest prior art, an electric all-wheel drive system with a star-delta connection for an electric transport vehicle is known from DE 10 2020 108 304 A1.

[0005] A method for controlling the longitudinal movement of a rail vehicle is known from DE 10 2012 014 012 A1.

[0006] A method for passing through a section is known from DE 198 49 276 A1.

[0007] A vibration damping method is known from DE 10 2016 200 006 A1. Summary of the Invention

[0008] Therefore, an object of the present invention is to improve the method for a transport vehicle, especially a curve-running rack manipulator, to smoothly pass through a bend.

[0009] According to the present invention, this object is achieved by a method according to the features given in claim 1 and a system according to the features given in claim 12.

[0010] In the method, an important feature of the present invention is to provide a method for operating a system including a transport vehicle, especially a rail vehicle, especially a curve-running rack manipulator,

[0011] Especially, the method is a method for controlling the longitudinal movement of a rail-type rack manipulator, and the rack manipulator is driven by at least two drive wheels guided on a common track at intervals in the traveling direction, that is, driven by front wheels and rear wheels.

[0012] Especially, a time-related course for the theoretical position of the transport vehicle is predefined.

[0013] Herein, the vehicle travels along a trajectory curve in the system by means of front wheels driven by a first drive device operating in a speed-controlled manner and rear wheels driven by a second drive device operating in a speed-controlled manner, wherein the trajectory curve has a straight section and at least one curved section, in particular a turning section.

[0014] In particular, the position controller generates a preset reference value such that the actual position of the vehicle is adjusted in the direction of the reference position, in particular, the actual position of the vehicle detected or determined at a corresponding current time is adjusted in the direction of a predefined reference position associated with the corresponding current time.

[0015] In particular, the torque introduced into the front wheels generated by the first drive device and the torque introduced into the rear wheels generated by the second drive device are determined.

[0016] Herein, a reference speed is predefined for the first drive device, which is determined by a first correction value added to the preset reference value. The first correction value is provided by a first path of the load compensation controller such that, in particular, as long as the front wheels and the rear wheels are respectively moving in corresponding sections of the straight section of the trajectory curve, the adjustment is always made in the direction of a predefined torque distribution between the first drive device and the second drive device / adjusted to the predefined torque distribution between the first drive device and the second drive device.

[0017] Herein, a reference speed is predefined for the second drive device, which is determined by a negative second correction value added to the preset reference value. The negative second correction value is provided by a second path of the load compensation controller such that, in particular, as long as the front wheels and the rear wheels are respectively moving in corresponding sections of the straight section of the trajectory curve, the torque distribution between the first drive device and the second drive device is always adjusted in the direction of the torque distribution reference value.

[0018] Herein, after it is recognized that the front wheels or the rear wheels enter a curved section, in particular a turning section, one of the paths of the load compensation controller is cut off, so that the preset reference value is used as the reference speed for the corresponding drive device and / or directly provided by the position controller.

[0019] The advantage at this time is that once it is recognized that the vehicle is turning, that is, either the front wheels or the rear wheels are in the curved section and / or the turning section of the trajectory curve, the path is cut off, and thus the corresponding drive device only obtains its reference value from the position controller, while the other drive device driving the wheels in the straight section still obtains the reference value corrected by the load compensation controller. In this way, a smooth entry from the straight section into the turning section can be achieved. Therefore, the vehicle is also only loaded with low forces, vibrations or force shocks. In this way, the transportation of sensitive goods can be achieved.

[0020] The position controller itself generates a theoretical value of the preset rotational speed, which is corrected by the load compensation controller. A signal related to the torque distribution is transmitted to the load compensation controller on the input side. Therefore, during straight-line driving, it is adjusted in the direction of a constant torque distribution and also in the direction of a predefined theoretical position trend related to time.

[0021] The recognition of turning driving can be ensured by checking additional criteria and can be considered in the logic control electronics by corresponding logic elements.

[0022] Alternatively, the method according to the invention can also be used in non-rail vehicles, but in which case, rail guidance achieves higher driving stability.

[0023] In an advantageous design, the difference between the theoretical position and the actual position of the vehicle is transmitted to a linear controller, especially a PI controller, of the position controller in particular. The position controller provides a preset theoretical value as a control value on the output side. The advantage here is that such a controller can be provided simply and at low cost. The actual position of the vehicle is achieved either by sensors for detecting the angular position of the corresponding wheels or by an independent system.

[0024] In an advantageous design, the corresponding drive device is operated in a speed-controlled manner, that is, in particular, the motor current of the corresponding drive device is set such that the actual rotational speed of the detected front or rear wheels driven by the drive device is adjusted in the direction of the theoretical rotational speed predefined for the drive device. The advantage here is that each drive device has a controller, to which the difference between the actual rotational speed and the theoretical rotational speed of the corresponding wheel is transmitted, and the controller prescribes a theoretical value of the motor current as a control variable to the current controller of the drive device. Therefore, a cost-effective and simple implementation can be achieved.

[0025] In an advantageous design, the load compensation controller generates a first correction value such that the currently determined torque distribution, that is, in particular, the actual value of the torque distribution, is adjusted in the direction of the theoretical torque distribution. The advantage here is that the desired torque distribution is achieved as well as possible at least during straight-line driving, that is, the loads on the drive devices are evenly distributed and thus a long service life can be achieved.

[0026] In an advantageous design, the load compensation controller generates a first correction value such that the currently determined torque distribution, i.e., in particular the actual value of the torque distribution, is fed to a first linear controller, in particular a PI controller. The control value of the first linear controller is limited by means of a first limiter, and as long as the front wheels and the rear wheels are moving in the straight section of the track curve, the limited control value is used as the first correction value; otherwise, the first correction value is zero. The advantage here is that the effect of the load compensation controller persists until a turning movement is recognized, and thus as constant a torque distribution as possible can be achieved. However, after a turning movement has been recognized, the path of the load compensation controller assigned to the wheel entering the cornering area is cut off.

[0027] In an advantageous design, the load compensation controller generates a second correction value such that the currently determined torque distribution, i.e., in particular the actual value of the torque distribution, is reversed, and the reversed torque distribution is adjusted in the direction of the theoretical torque distribution value. The advantage here is that during rear-wheel turning, it is also possible to cut off the drive assigned to the rear wheels.

[0028] In an advantageous design, the load compensation controller generates a second correction value such that the currently determined torque distribution, i.e., in particular the actual value of the torque distribution, is reversed, and the reversed torque distribution is fed to a second linear controller, in particular a PI controller. The control value of the second linear controller is limited by means of a second limiter, and as long as the front wheels and the rear wheels are moving in the straight section of the track curve, the limited control value is used as the second correction value; otherwise, the second correction value is zero. The advantage here is that the load compensation controller generates a correction signal, i.e., a correction value, by which the preset theoretical value of the position controller can be corrected, so that a more uniform torque distribution can be achieved. However, when entering a curve, the correction signal for the relevant drive is cut off, and thus a smooth entry into the cornering area can be achieved. It should be noted here that always only one of the two wheels is in one or the cornering area. For this purpose, the bend of the cornering area is not more than 90°.

[0029] In an advantageous design, the recognition is carried out in a hysteretic manner. The advantage here is that stable operating performance can be achieved.

[0030] In an advantageous design, the first path of the load compensation controller has a linear controller, in particular a PI controller, as well as a limiter and logic control electronics, and the control value determined by the linear controller and limited by the limiter is fed to the logic control electronics.

[0031] The linear controller is fed with the currently determined torque distribution on the input side. This has the advantage that a control value can be generated from the difference in the actual torque values ​​of the two drives, which can be added as a correction value to the preset setpoint value of the position controller as long as no bends are being driven.

[0032] In an advantageous embodiment, the torque distribution is equal to the quotient of the torque generated by the first drive and introduced into the front wheels and the torque generated by the second drive and introduced into the rear wheels. The advantage here is that the torque distribution can be determined as the quotient of the actual torque values ​​of the two drive devices and can therefore be adjusted in a simple manner in the direction of the target torque distribution.

[0033] In an alternative advantageous embodiment, the torque distribution setpoint value is zero and the difference between a first product and a second product is used as the torque distribution, wherein the first product is the torque of the first drive multiplied by a first amplification factor and the second product is the torque of the second drive multiplied by a second amplification factor, in particular wherein the first amplification factor is a predetermined constant value and the second amplification factor is a different predetermined constant value. The advantage here is that the torque difference of the two drives weighted by the respective amplification factors can be used as the torque distribution.

[0034] In an advantageous embodiment, the control value of the first linear controller limited by means of the first limiter is a first rotational speed compensation value, and the control value of the second linear controller limited by means of the second limiter is a second rotational speed compensation value, wherein the entry of the front wheel or the rear wheel into a curved region, in particular a cornering region, is detected by:

[0035] - comparing the difference between the first rotational speed compensation value and the second rotational speed compensation value with a threshold value, in particular with a hysteresis,

[0036] - and comparing an average value determined from the first rotational speed compensation value and the second rotational speed compensation value with a second threshold value.

[0037] This has the advantage that the entry of one of the wheels into a curve can be detected with certainty by means of the comparison of the two rotational speed compensation values ​​which are present in both paths of the load compensation control system.

[0038] An important feature of the system for carrying out the above method is that the vehicle is guided by rails, wherein, in particular in the track direction, straight areas of the track path are adjoined on both sides by curved areas of the track path, wherein the front wheels of the vehicle can be driven by a first drive device and the rear wheels can be driven by a second drive device, wherein the front wheels and the rear wheels are spaced apart from one another in the track direction. This has the advantage that the trajectory curve can be fixedly predefined as a track system and thus a stable operation can be achieved.

[0039] In an advantageous design, the distance between the rotational axis of the front wheels and the rotational axis of the rear wheels is greater than 1.5 times the radius of the bend. In particular, the front and rear wheels are not simultaneously in the bend. In particular, the bend has a maximum bending angle of 90°, i.e., in particular, the steering generated by the bend is at most 90°. The advantage here is that only a single wheel is always in the bend. Therefore, it is possible to quickly and simply identify the entry of one of the wheels into the bend, so that the path can be quickly interrupted, such that no significant impact occurs when entering the turning area.

[0040] In an advantageous design, the first drive device has a first electric motor supplied by a first inverter, and the second drive device has a second electric motor supplied by a second inverter. The advantage here is that each of the two electric motors can be operated in a controlled manner, in particular in a speed-controlled manner. For this purpose, a setpoint speed is specified for each of the drive devices, and the respective drive device is adjusted in the direction of this speed, in particular by specifying a setpoint motor current and adjusting the actual motor current in the direction of this setpoint motor current by appropriately adjusting the motor voltage.

[0041] In an advantageous design, the vehicle has a position controller, the output signal of which is fed to the first input of an adder, and a correction signal generated by a first path of a load compensation controller is fed to the second input of the adder. The output signal of the adder device is, in particular, fed as a setpoint speed to the first drive device. The logic control electronics of the vehicle are implemented such that the first path is interrupted according to a release signal, which is generated by a device for identifying a bend. In particular, the device for identifying a bend has a comparison device to which a first compensation signal generated in the first path and a second compensation signal generated in the second path are fed. The first compensation signal is generated by a linear controller with a limiter connected downstream. The output signal of a subtractor, which is implemented in a suitable manner such that the output signal is the difference between

[0042] - the first torque generated by the drive device of the front wheels and multiplied by a first amplification factor and

[0043] - the second torque generated by the drive device of the rear wheels and multiplied by a second amplification factor

[0044] is fed to the input side of the linear controller. The advantage here is that the vehicle has a position controller that can be simply and cost-effectively implemented, and the output signal of the load compensation controller is superimposed on the control value of the position controller as a correction signal, such that the setpoint value for the respective drive device is directly provided by the position controller only in the case of a turning maneuver.

[0045] Other advantages result from the dependent claims. The invention is not limited to the combinations of features stated in the claims. For a person skilled in the art, other reasonable combinations of the claims and / or of the features of the individual claims and / or of the description and / or of the drawings result, in particular, from the purpose setting and / or from the purposes arising from a comparison with the prior art. Description of the Drawings

[0046] The invention will now be explained in more detail with reference to the schematic drawings:

[0047] In Figure 1 the turning control of a vehicle 50 according to the invention, in particular of a rack handling machine, is schematically shown, wherein a load compensation controller 3 supplies a rotational speed correction value to a logic control electronics 7, which is added to the control variable of a position controller 2.

[0048] In Figure 2 a first part of the logic control electronics 7 is schematically shown.

[0049] In Figure 3 exemplary turning requirements are shown.

[0050] In Figure 4 a second part of the logic control electronics 7 is shown, wherein the output signal actuates the first part.

[0051] In Figure 5 the turning travel of the vehicle 50, in particular of a rack handling machine, is schematically drawn. Detailed Description of the Invention

[0052] As shown in Figure 1 a travel path 1 is predefined, which describes the relationship between the position s and the time t of the vehicle 50, in particular of a rack handling machine moving in a curve. Thus, in particular as a preset theoretical value, the goal is for the vehicle to follow this travel path 1 along the path curve.

[0053] The vehicle has a first drive device 11 and a second drive device 12 spaced apart from the first drive device. Each of these two drive devices (11, 12) has an electric motor which drives the respective wheels. Preferably, the first drive device drives the front wheels of the vehicle 50 and the second drive device 12 drives the rear wheels.

[0054] In particular, the chassis 13 of the vehicle 50 has these two drive devices (11, 12) and is preferably embodied as a rail-guided, in particular rail-guided and / or curve-traveling rack handling machine.

[0055] When driving straight, the torque distribution on the two drive units (11, 12) is constant. For example, each of the two drive units (11, 12) must apply the same torque share. The torque distribution is predefined by the parameters kM1 and kM2 and preferably remains constant during operation.

[0056] Now, if the vehicle enters a curve, i.e., the front wheels are in the turning area while the rear wheels are still in a straight track section, the load compensation controller 3 may actually try to balance the resulting change in the actual torque value and, for this purpose, increase the predefined setpoint value nSOLL1 for the front wheel speed. To prevent this, after it is recognized that the front wheels have entered the curve, the corresponding path in the load compensation controller 3 is deactivated by outputting zero as the correction value n_Korrektur_1 as n_Kurve_max, and thus the predefined setpoint value determined by the position controller 2 for the first drive unit 1 remains unchanged. Conversely, of course, the torque deviation between the first drive unit (11) and the second drive unit (12) is taken into account in another path, and a negative value, i.e., n_Korrektur_2, is added to the predefined setpoint value of the position controller 2 for the second drive unit 12, i.e., in particular, the speed of the rear wheels is affected.

[0057] As can be seen in Figure 5 the front and rear wheels are spaced apart from each other to such an extent that the turning area can be spanned, i.e., in the shown 45° position, the two wheels are arranged in a straight section adjacent to the curve section.

[0058] Therefore, the present invention does not have a master-slave control but treats the two drive units (11, 12) in the same way.

[0059] As can be seen in Figure 1As shown, a theoretical position value associated with a corresponding current moment is obtained from the driving trajectory 1, and the difference between the theoretical position and the actual position value is fed to a controller, in particular a P controller or a PI controller. The actual position is determined by angle sensors (G1, G2) arranged at the drive devices (11, 12). Here, the angle sensors (G1, G2) detect the rotational positions of the respective rotor shafts of the respective motors of the respective drive devices (11, 12). The motors directly drive the wheels of the vehicle 50 or, via a transmission, i.e., indirectly drive the wheels of the vehicle 50. The position of the vehicle 50 is determined from the angle positions detected by the angle sensors (G1, G2), in particular by means of a magnification factor that is proportional to the value determined from the values detected by the two angle sensors (G1, G2). In particular, the wheels, i.e., in particular the front wheels and the rear wheels, convert the rotation of the drive devices (11, 12) into a distance change along the trajectory curve, i.e., in particular a movement in the driving plane. Therefore, the distance traveled by the vehicle 50 is proportional to the angular distance traveled by the respective rotor shafts of the drive devices (11, 12). By means of summation, the distance change can be determined with high precision.

[0060] A first correction value n_Korrektur_1 is added to the control variable determined by the position controller 2 from the difference between the actual position value and the theoretical position value, and the thus determined theoretical speed nSoll1 is prescribed for the first drive device 11.

[0061] Correspondingly, a second correction value n_Korrektur_2 is added to the control variable determined by the position controller 2 from the difference between the actual position value and the theoretical position value, and the thus determined second theoretical speed nSoll2 is prescribed for the second drive device 11.

[0062] Each drive device (11, 12) has an inverter that supplies power to the motor of the respective drive device (11, 12), so that the rotational speed of the respective motor can be controlled or even regulated. Preferably, in the signal electronics of the drive devices (11, 12), estimated values or model values are used to determine the torque output by the motor and used as the actual values (M1, M2) of the torque.

[0063] In the load compensation controller 3, the difference between the torque values M1 and M2 determined in this way and multiplied by the magnification factors km1 or km2 is determined.

[0064] By feeding this difference to the load compensation controller 3, the load compensation controller determines the first correction value n_Korrektur_1. On the one hand, at this time, this difference is fed to the first controller 5 of the load compensation controller 3, especially a PI controller. The first controller is followed by a limiter 6, and the output signal N_Ausgleich_1 of the limiter is fed to the logic control electronics 7.

[0065] On the other hand, the load compensation controller 3 determines the second correction value n_Korrektur_2. For this purpose, the reversed difference is fed to the second controller 5 of the load compensation controller 3, especially a PI controller. The second controller is followed by a second limiter 6, and the output signal n_Ausgleich_2 of the second limiter is also fed to the logic control electronics 7.

[0066] That is, as specifically shown in Figure 1 the actual value of the torque M1 of the first drive device 11 is multiplied by the first amplification factor kM1, that is, the first product is determined.

[0067] Similarly, the actual value of the torque M2 of the second drive device 12 is multiplied by the second amplification factor kM2, that is, the second product is determined.

[0068] The difference between the first product and the second product is fed to a first path. The first path has a first controller, especially a PI controller. A first limiter 6 is connected after the first controller. The output signal n_Ausgleich_1 of the first limiter is fed to the logic control electronics 7, especially to the connection terminal A of the switch arranged in the Figure 2 upper path in Figure 2 This switch is controlled by the control signal Switch_n1. When the vehicle 50 is driving straight, the switch remains in the Figure 1 switch position shown in

[0069] That is, therefore, the signal n_Ausgleich_1 is output as n_Korrektur_1 and is added to the output signal of the position controller 2 as shown in Figure 2

[0070] Figure 1 As in Figure 1As shown, the reverse difference between the first product and the second product is fed to a second path, which has a second controller 5, the second controller having a second limiter 6 connected downstream, the output signal n_Ausgleich_2 of the second limiter being fed to a logic control electronics 7, in particular to the connection terminal A of a switch arranged in the Figure 2 lower path shown, the switch being actuated by a control signal Switch_n2. When the vehicle 50 is traveling in a straight line, the switch remains in the Figure 2 switch position shown. That is, the signal n_Ausgleich_2 is thus output as n_Korrektur_2 and, as Figure 1 shown, is added to the output signal of the position controller 2, so that the sum thus obtained is prescribed for the second drive device 12 in this way as the set speed nSOLL2.

[0071] The recognition of a bend by means of the logic control electronics 7 is carried out in the Figure 3 way shown. At this time, the difference between the output signal n_Ausgleich_1 of the first limiter 6 and the output signal n_Ausgleich_2 of the second limiter 6 is compared with two threshold values n_Diff_AUS and n_Diff_EIN, so that a bend can be recognized in a hysteretic manner.

[0072] For the recognition, the logic control electronics 7 according to Figure 4 has a second partial area 40. For this purpose, the two signals n_Ausgleich_1 and n_Ausgleich_2 are fed to the input terminals of functional blocks (41, 42, 43, 44), the first input terminal in the Figure 4 corresponding upper part shown being designated by A and the second input terminal in the Figure 4 corresponding lower part shown being designated by B. The output signals of the corresponding functional blocks (41, 42, 43, 44) are formed according to the functions shown accordingly.

[0073] In the first functional block 41, the difference between the magnitudes of the signals n_Ausgleich_1 and n_Ausgleich_2 is determined and this difference is fed to another functional block 45, which has a hysteretic switching behavior and whose binary output signal is fed to an arithmetic element 47.

[0074] The second functional block 42 determines the average value of the two signals n_Ausgleich_1 and n_Ausgleich_2 as the output signal, and in another functional block 46 it is monitored whether this average value exceeds a constant threshold value n_Kurve_min. The binary output signal of this other functional block 46 is likewise fed to the arithmetic element 47.

[0075] The third functional block 43 monitors whether the signal n_Ausgleich_1 exceeds the signal n_Ausgleich_2. The binary output signal of the third functional block 43 is fed to an AND gate, and the output signal of the arithmetic element 47 is also fed to this AND gate. The output signal of the first AND gate is the switching signal Switch_n1 for the upper switch in Figure 2 the middle.

[0076] The fourth functional block 44 monitors whether the signal n_Ausgleich_2 exceeds the signal n_Ausgleich_1. The binary output signal of the fourth functional block 44 is fed to a second AND gate, and the output signal of the arithmetic element 47 is also fed to this second AND gate. The output signal of the second AND gate is the switching signal Switch_n2 for the lower switch in Figure 2 the middle.

[0077] The output signal of the arithmetic element indicates whether one of the wheels of the vehicle 50 has entered a curve.

[0078] Therefore, the present invention enables a smooth entry into a curve, where nevertheless a high speed can be maintained. Even if the center of gravity of the vehicle 50 is arranged very high, tipping over during high-speed travel along a track curve can still be avoided. The same applies when exiting the curve. In addition, the vehicle 50 is not overloaded and thus can achieve a longer service life.

[0079] As Figure 5 shown, the distance between the front wheels and the rear wheels is greater than 1.5 times the radius of the curve. Therefore, the front wheels and the rear wheels are not simultaneously in the curve, especially where the curve has a maximum bending angle of 90°, that is, especially the steering generated due to the curve is at most 90°.

[0080] In a further embodiment according to the invention, instead of the difference between the output signal n_Ausgleich_1 of the first limiter 6 and the output signal n_Ausgleich_2 of the second limiter 6, the difference between the above-mentioned first product and the second product is used.

[0081] In a further embodiment according to the invention, instead of the shelf manipulator, another rail-guided vehicle 50 is used, which has front wheels driven by a first drive device 11 and rear wheels driven by a second drive device 12.

[0082] List of reference numerals

[0083] 1 Travel trajectory

[0084] 2 Position controller

[0085] 3 Load compensation controller

[0086] 4 Torque comparison

[0087] 5 Controller, especially PI controller

[0088] 6 Limiter

[0089] 7 Logic control electronic device

[0090] 8 Parameter

[0091] 9 Parameter

[0092] 10 Parameter

[0093] 11 First drive device for speed control with angle sensor

[0094] 12 Second drive device for speed control with angle sensor

[0095] 13 Chassis of the rack operating machine

[0096] 14 Encoder feedback

[0097] 15 Proportional element

[0098] 20 First partial area of the logic control electronic device 7

[0099] 40 Second partial area of the logic control electronic device 7

[0100] 41 Function block

[0101] 42 Function block

[0102] 43 Function block

[0103] 44 Function block

[0104] 45 Function block

[0105] 46 Function block

[0106] 47 Logic operation element function block

[0107] 50 Vehicle, especially rack operating machine

[0108] G1 Angle sensor of the first drive device 11

[0109] G2 Angle sensor of the second drive device 12

[0110] Km1 First amplification factor

[0111] Km2 Second amplification factor

[0112] n_Diff_EIN Switch signal

[0113] n_Diff_AUS Switch signal

[0114] The theoretical value of the minimum rotational speed of the n_Kurve_min

[0115] The theoretical value of the maximum rotational speed of the n_Kurve_max Setpoint

[0116] The torque of M1, the first drive 11

[0117] The torque of M2, the second drive 12

[0118] The actual rotational speed of the first drive 11, nIST1

[0119] The actual rotational speed of the second drive 12, nIST2

Claims

1. A method for operating a system comprising a vehicle, in particular a rail vehicle, in particular a shelf handling machine for curve travel, in particular a method for controlling the longitudinal movement of a rail-mounted shelf handling machine, the shelf handling machine being driven by at least two drive wheels guided on a common rail at intervals from each other in the travel direction, i.e., driven by a front wheel and a rear wheel, in particular wherein a time-dependent course for the theoretical position of the vehicle is predefined, wherein the vehicle travels in the system along a track curve by a front wheel driven by a first drive device operating in a speed-controlled manner and a rear wheel driven by a second drive device operating in a speed-controlled manner, wherein the track curve has a straight section and at least one curved section, in particular a turning section, wherein, in particular, a preset theoretical value is generated by a position controller such that the actual position of the vehicle is adjusted in the direction of the theoretical position, in particular, the actual position of the vehicle detected or determined at a corresponding current time is adjusted in the direction of the predefined theoretical position associated with the corresponding current time, in particular wherein the torque introduced into the front wheel generated by the first drive device and the torque introduced into the rear wheel generated by the second drive device are determined, wherein a theoretical speed is predefined for the first drive device, the theoretical speed being determined by a first correction value added to the preset theoretical value, and the first correction value is provided through a first path of a load compensation controller such that, in particular, as long as the front wheel and the rear wheel are respectively moving in corresponding sections of the straight section of the track curve, the torque distribution between the first drive device and the second drive device is continuously adjusted to a predefined torque distribution, wherein a theoretical speed is predefined for the second drive device, the theoretical speed being determined by a negative second correction value added to the preset theoretical value, and the second correction value is provided through a second path of the load compensation controller such that, in particular, as long as the front wheel and the rear wheel are respectively moving in corresponding sections of the straight section of the track curve, the torque distribution between the first drive device and the second drive device is continuously adjusted in the direction of the theoretical torque distribution value, wherein, after it is recognized that the front wheel or the rear wheel enters a curved section, in particular a turning section, one of the paths of the load compensation controller is cut off, so that the preset theoretical value is used as the theoretical speed for the corresponding drive device and / or is directly provided by the position controller.

2. The method according to claim 1, characterized in that the difference between the theoretical position and the actual position of the vehicle is fed to a linear controller, in particular a PI controller, of the position controller in particular, and the position controller provides a preset theoretical value as a control value at the output side.

3. The method according to claim 1 or 2, characterized in that the corresponding drive device is operated in a speed-controlled manner, i.e., in particular, the motor current of the corresponding drive device is set such that the actual speed of the front wheel or the rear wheel driven by the drive device is adjusted to the theoretical speed predefined for the drive device.

4. The method according to any one of the above claims, characterized in that The load compensation controller generates a first correction value such that the currently determined torque distribution, in particular the actual value of the torque distribution, is adjusted to the theoretical value of the torque distribution.

5. The method according to any one of the preceding claims, characterized in that the load compensation controller generates a first correction value such that the currently determined torque distribution, in particular the actual value of the torque distribution, is fed to a first linear controller, in particular a PI controller, the control value of the first linear controller is limited by means of a first limiter, and as long as the front wheels and the rear wheels are moving in the straight-line region of the trajectory curve, the thus limited control value is used as the first correction value, otherwise the first correction value is zero.

6. The method according to any one of the preceding claims, characterized in that the load compensation controller generates a second correction value such that the currently determined torque distribution, in particular the actual value of the torque distribution, is reversed, and the thus reversed torque distribution is adjusted to the theoretical value of the torque distribution.

7. The method according to any one of the preceding claims, characterized in that the load compensation controller generates a second correction value such that the currently determined torque distribution, in particular the actual value of the torque distribution, is reversed, and the thus reversed torque distribution is fed to a second linear controller, in particular a PI controller, the control value of the second linear controller is limited by means of a second limiter, and as long as the front wheels and the rear wheels are moving in the straight-line region of the trajectory curve, the thus limited control value is used as the second correction value, otherwise the second correction value is zero.

8. The method according to any one of the preceding claims, characterized in that the identification is carried out in a hysteretic manner.

9. The method according to any one of the preceding claims, characterized in that the first path of the load compensation controller has a linear controller, in particular a PI controller, as well as a limiter and logic control electronics, the control value determined by the linear controller and limited by means of the limiter is fed to the logic control electronics, wherein the currently determined torque distribution is fed to the linear controller on the input side.

10. The method according to any one of the preceding claims, characterized in that the torque distribution is equal to the quotient of the torque generated by the first drive device and introduced into the front wheels and the torque generated by the second drive device and introduced into the rear wheels, or the theoretical value of the torque distribution is zero, and as the torque distribution, the difference between a first product and a second product is used, wherein the first product is the torque of the first drive device multiplied by a first amplification factor, and the second product is the torque of the second drive device multiplied by a second amplification factor, in particular wherein the first amplification factor is a predefined constant value and the second amplification factor is a different predefined constant value.

11. The method according to any one of the preceding claims, characterized in that the control value of the first linear controller limited by means of the first limiter is a first rotational speed compensation value, and the control value of the second linear controller limited by means of the second limiter is a second rotational speed compensation value, Among them, the entry of the front wheel or the rear wheel into a curved area, especially a cornering area, is recognized by the following method: - In particular, the difference between the first rotational speed compensation value and the second rotational speed compensation value is compared with a threshold value in a lagged manner. - And the average value formed by the first rotational speed compensation value and the second rotational speed compensation value is compared with a second threshold value.

12. A system for performing the method according to any one of the above claims, characterized in that the vehicle is guided by a track, wherein, in particular along the track direction, the straight sections of the track route are adjacent to the curved sections of the track route on both sides. Among them, the front wheels of the vehicle can be driven by a first drive device, and the rear wheels can be driven by a second drive device. Among them, the front wheels and the rear wheels are spaced apart from each other along the track direction.

13. The system according to any one of the above claims, characterized in that the distance between the rotational axis of the front wheel and the rotational axis of the rear wheel is greater than 1.5 times the radius of the bend. In particular, so that the front wheels and the rear wheels are not simultaneously in the bend, especially where the bend has a maximum bending angle of 90°, that is, especially the steering generated by the bend is at most 90°.

14. The system according to any one of the above claims, characterized in that the first drive device has a first motor powered by a first inverter. the second drive device has a second motor powered by a second inverter.

15. The system according to any one of the above claims, characterized in that the vehicle has a position controller, the output signal of which is fed to the first input of an adder, and a correction signal generated by a first path of a load compensation controller is fed to the second input of the adder. Among them, the output signal of the adder device is fed to the first drive device as the nominal rotational speed, wherein the logic control electronics of the vehicle are implemented to cut off the first path according to a release signal. wherein the release signal is generated by a device for recognizing a bend. In particular, the device for recognizing a bend has a comparison device, to which a first compensation signal generated in the first path and a second compensation signal generated in the second path are fed. Among them, the first compensation signal is generated by a linear controller with a limiter connected downstream. Among them, the output signal of a subtractor is fed to the input side of the linear controller, and the subtractor is implemented in a suitable manner such that the output signal is - the difference between the first torque generated by the drive device of the front wheel and multiplied by a first amplification factor and - the second torque generated by the drive device of the rear wheel and multiplied by a second amplification factor.

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