METHOD FOR AUTOMATICALLY TRANSFERRING A PIVOTABLE TROLLEY POLE

Abstract

A method for automatically transferring at least one pivotable trolley pole, in particular of a trolleybus, from a start position into an end position which corresponds, in particular, to a contact position on an overhead line. The end position is assigned at least one setpoint position value, at least one actual position value of a current position of the trolley pole is detected, and the trolley pole is pivoted automatically about at least one axis. A setpoint speed is determined from a positional deviation of the detected actual position value from the setpoint position value, and a dynamic limitation to a dynamically limited setpoint speed is carried out in order to avoid overshooting when the end position is reached.

A separate sheet setting forth the replacement Abstract is provided herewith.

Claims

1. A method for automatically transferring at least one pivotable trolley pole from a start position into an end position, wherein at least one setpoint position value is assigned to the end position, at least one actual position value of a current position of the trolley pole is detected and the trolley pole is pivoted automatically about at least one axis, wherein a setpoint speed is determined from a positional deviation of the detected actual position value from the setpoint position value and is dynamically limited to a dynamically limited setpoint speed to prevent overshooting when the end position is reached.

2. The method according to claim 1, wherein the dynamic limitation of the setpoint speed is dependent on the positional deviation of the actual position value from the setpoint position value.

3. The method according to claim 2, wherein a stronger dynamic limit is set for smaller positional deviations relative to the dynamic limit for larger positional deviations.

4. The method according to claim 1, wherein the setpoint speed to be limited is determined from the positional deviation and a linear calculation factor.

5. The method according to claim 1, wherein for dynamic limitation, a maximum permissible speed is specified as a function of the positional deviation.

6. The method according to claim 5, wherein for dynamic limitation, the setpoint speed to be limited and the maximum permissible speed are compared with each other.

7. The method according to claim 5, wherein the value of the maximum permissible speed, if the setpoint speed to be limited is greater than the maximum permissible speed, or the value of the setpoint speed to be limited, if the setpoint speed to be limited is less than the maximum permissible speed, is used as the value of the dynamically limited setpoint speed.

8. The method according to claim 1, wherein an actual speed is determined from the recorded actual position value.

9. The method according to claim 1, wherein a manipulated variable for swiveling the trolley pole is determined from the dynamically limited setpoint speed and the actual speed.

10. The method according to claim 9, wherein the manipulated variable is determined as the output variable of a proportional-integral control with the difference between the dynamically limited setpoint speed and the actual speed as the input variable.

11. The method according to claim 1, wherein the trolley pole is automatically swiveled about a horizontal axis and a vertical axis.

12. The method according to claim 1, wherein the trolley pole is continuously moved from the start position to the end position.

13. The method according to claim 1, wherein the at least one actual position value is recorded as an actual angle value.

14. The method according to claim 13, wherein a detected actual angle value is converted into an actual height value to control the swiveling about a horizontal axis.

15. The method according to claim 1, wherein the end position is at least one of: determined from sensor data, or taken from a database.

16. A current collector system for arrangement on a vehicle roof with at least one pivotable trolley pole, which for transfer from a start position to an end position, to which at least one setpoint position value is assigned, is automatically pivotable about at least one axis, with a control unit for controlling the transfer and with at least one means for detecting at least one actual position value of the current position of the trolley pole, wherein the control unit is set up to determine a setpoint speed from a positional deviation of a detected actual position value from the setpoint position value and to limit it dynamically to a dynamically limited setpoint speed in order to avoid overshooting when the end position is reached.

17. The current collector system according to claim 16, wherein the control unit is part of a modular control device.

18. The current collector system according to claim 16, further including pneumatic actuators for swiveling the trolley pole about at least one of a horizontal axis or a vertical axis.

19. The current collector system according to claim 16, further including sensors for detecting the relative position of an overhead line.

20. The method according to claim 1, wherein the trolley pole is a trolley pole of a trolley bus, and wherein the end position corresponds to a contact position on an overhead line.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further details and advantages of a method according to the disclosure and of a current collector system according to the disclosure will be explained below by means of an exemplary embodiment shown schematically in the figures described below.

[0039] FIG. 1a shows a vehicle with a current collector system from the side;

[0040] FIG. 1b shows a vehicle with a current collector system from the top;

[0041] FIG. 2 shows the progression over time of the actual position value and the actual speed in a method for automatically transferring according to the state of the art,

[0042] FIG. 3 shows the progression over time of the actual position value and the actual speed in the method according to the disclosure; and

[0043] FIG. 4 shows the schematic structure of a control unit for carrying out the method according to the disclosure.

DETAILED DESCRIPTION

[0044] FIG. 1a and FIG. 1b show a trolley bus 100, which is connected to a line net consisting of two overhead lines 200 via a current collector system 1. The current collector system 1 is arranged on the vehicle roof 110. In order to connect the trolley bus 100 to the overhead lines 200, the current collector system has two trolley poles 2. As long as the trolley bus 100 does not need to be supplied with power via the overhead lines 200, the trolley poles 2 rest on the vehicle roof 110 in their respective rest position.

[0045] If a connection is now to be established with the overhead lines 200, the trolley poles 2 are each brought into a contact position in which they are in contact with one of the overhead lines 200. In the contact position, an electrical connection is established between the trolley bus 100 and the overhead lines 200 via the trolley poles 2, which is also referred to as wiring. During this wiring, each of the trolley poles 2 is thus transferred from its rest position, which represents a start position 3, to its contact position, which represents an end position 4. Each of the trolley poles 2 has a hinged end 2.1 about which the trolley pole 2 can be swiveled about a horizontal axis 5 and a vertical axis 6, so that a free end 2.2 of the respective trolley pole 2 can be moved in space relative to the trolley bus 100 in order to be brought into contact with one of the overhead lines 200. In order to enable this swiveling about the axes 5, 6, the current collector system 1 has several actuators 18, which enable swiveling about the respective axes 5, 6 and are designed as pneumatic cylinders in the exemplary embodiment shown.

[0046] During the transfer from the start position 3 to the end position 4, the trolley pole 2 is raised in a vertical plane when swiveling about the horizontal axis 5, as shown in FIG. 1a together with several intermediate steps. In this way, the free end 2.2 of the trolley pole 2 is raised to the height of the overhead line 200. When swiveling about the vertical axis 6, the trolley pole 2 is swiveled to the side in a horizontal plane, as shown in FIG. 1. Each of the two trolley poles 2 can be swiveled about its own vertical axis 6, which run parallel to each other and intersect the common horizontal axis 5 essentially at right angles. By swiveling in the horizontal plane, the position of the trolley pole 2 can be adapted to the route of the overhead line 200 if, for example, the trolley bus 100 is at an angle to the overhead line 200 or laterally offset to it, as shown in FIG. 1b.

[0047] For each axis 5, 6, both the end position 4 and the start position 3 are each assigned a setpoint position value .sub.S or a start position value .sub.0, which in the exemplary embodiment is the angle that the trolley pole 2 assumes when swiveling around the respective axis 5, 6 in the end position 4 or the start position 3. In order to enable automatic transfer of the trolley pole 2 to the end position 4, the current collector system 1 can detect the current position of the trolley pole 2. For this purpose, the current collector system 1 has at least one means or mechanism/system for detecting an actual position value for each of the axes 5, 6, which in the exemplary embodiment is the angle around the respective axis 5, 6 at which the trolley pole 2 is currently positioned. The actual position value , the start position value .sub.0 and the setpoint position value .sub.S can be detected relative to the rest position of the trolley pole 2, so that the start position value .sub.0 can assume the value zero for the exemplary embodiment of FIG. 1, as the transfer shown takes place from the rest position as the start position 3.

[0048] In contrast to the method according to the disclosure for automatically transferring the trolley pole 2, the methods known from the prior art cause the trolley pole 2 to overshoot beyond the setpoint position value .sub.S assigned to the end position 4, as shown in FIG. 1a. Due to the inertia of the trolley pole 2, it continues to move after reaching the setpoint position value .sub.S and only comes to a standstill at an overshoot position .sub.U. In order to complete the transfer to the end position 4, the trolley pole 2 must therefore be guided from the overshoot position .sub.U back to the setpoint position value .sub.S, which makes the known transfer methods time-consuming. Such an overshoot of the trolley pole 2 also causes an unwanted mechanical load on the overhead line 200 due to the force exerted on it by the trolley pole and also harbors the risk of the overhead line 200 being missed in the horizontal plane, for example due to an overshoot.

[0049] FIG. 2 shows the progression over time of the actual position value and the actual speed of the trolley pole 2 during a known automatic transfer. The transfer of the trolley pole 2 from the start position 3 to the end position 4 begins at the time t.sub.0, at which the actual position value corresponds to the start position value .sub.0. Starting from the start position value .sub.0, the trolley pole 2 is accelerated so that its actual speed increases. Due to the inertia of the trolley pole 2, the increase in the actual speed is not sudden, but takes place over a certain period of time until the actual speed assumes a largely constant value. With this actual speed , the actual position value approaches the setpoint position value .sub.S assigned to the end position 4 until the time t.sub.1, at which the actual position value corresponds to the setpoint position value .sub.S. From this point in time t.sub.1, the actual speed is reduced, but cannot be abruptly set to zero due to the inertia of the trolley pole 2, so that the trolley pole 2 and thus also its actual position value continues to change beyond the setpoint position value .sub.S.

[0050] Only at time t.sub.2 the actual speed reaches the value zero, so that the trolley pole 2 comes to a stop. At time t.sub.2, however, the trolley pole 2 assumes the overshoot position .sub.U, which deviates from the setpoint position value .sub.S. In order to complete the transfer to the end position 4, i.e. to bring the actual position value into alignment with the setpoint position value .sub.S for a stationary trolley pole 2, the actual position value must be returned from the overshoot position .sub.U to the setpoint position value .sub.S. To do this, the trolley pole 2 is moved in the opposite direction, whereby the actual speed assumes a negative value. At the time t.sub.3, the actual position value then corresponds to the setpoint position value .sub.S, while the actual speed is zero at the same time. Only under these conditions the automatic transfer is completed without human intervention.

[0051] The progression over time of the actual position value Y and the actual speed is shown in simplified form in FIG. 2. In practical implementation, further overshoots above the setpoint position value .sub.S can occur between time t.sub.2 and time t.sub.3, so that the transition can only be completed after a longer settling process.

[0052] In contrast to FIG. 2, FIG. 3 shows the progression over time of the actual position value and the actual speed during a transfer of the trolley pole 2 from the start position 3 to the end position 4 in accordance with the method according to the disclosure. Here too, the actual position value begins at the start time t.sub.0 of the transfer at the start position value .sub.0 and is changed by the increasing actual speed in the direction of the setpoint position value .sub.S. Due to the dynamic limitation that is dependent on the positional deviation , which is described in more detail below, a control unit 10 of the current collector system 1 that controls the transfer reduces the actual speed at a point in time t.sub.1 at which the actual position value does not yet match the setpoint position value .sub.S. In the method according to the disclosure, the trolley pole 2 is already braked when the positional deviation of the detected actual position value from the setpoint position value .sub.S is still not equal to zero.

[0053] Due to the inertia of the trolley pole 2, the actual speed can only be reduced continuously from the time t.sub.1, but not abruptly. Accordingly, the actual position value Y continues to move in the direction of the setpoint position value .sub.S even after the time t.sub.1. The actual speed only assumes the value zero at the time t.sub.2, so that the trolley pole 2 comes to rest. The dynamic limitation according to the disclosure is designed in such a way that the actual position value at time t.sub.2 corresponds to the setpoint position value .sub.S and the transfer is therefore completed without overshooting and, in particular, without a transient process. The trolley pole 2, which is articulated on one side, is gently braked as it approaches the setpoint position value .sub.S in such a way that no whiplike overshoot of the free end 2.2 occurs. The end position 2 is therefore approached in a time-saving and more reliable manner.

[0054] As can be seen in FIG. 3, the actual position value is continuously transferred from the start position value .sub.0 to the setpoint position value .sub.S. This continuous transfer can take place both for the actual position value of a swiveling movement around axis 5 and for the actual position value of a swiveling movement around axis 6. As the actual position values of the swivels around the horizontal axis 5 and around the vertical axis 6 represent coordinates of a spherical coordinate system that are independent of each other, these individual continuous transfers to the setpoint position values .sub.S can be carried out in parallel or in series.

[0055] FIG. 4 shows the schematic structure of the control unit 10, which is used to carry out the method for automatically transferring according to the disclosure. The setpoint position value .sub.S and the actual position value serve as input variables for this control system. The setpoint position value .sub.S can, for example, be taken from a database in which the height of the overhead line 200 or an angle to be assumed for contacting by the trolley pole 2 is stored in a spatially resolved manner, depending on the position of the trolley bus 100, or can be determined from sensor data of a sensor of the current collector system 1 used to detect the relative position of the overhead line 200.

[0056] The actual position value is detected by the at least one means/mechanism/system of the current collector system 1 provided for detecting it. If the actual position value is detected as an actual angle value by the means/mechanism/system for detecting it, but the setpoint position value .sub.S is available as a length dimension, such as a height above the vehicle roof 110, a conversion not shown in the figure can be carried out beforehand. During this conversion, the recorded actual angle value is converted into an actual height value and this is used as the actual position value in the further process. Alternatively, the setpoint position value .sub.S can also be converted into an angle measurement. Using the known length of the swiveling trolley pole 2, such a conversion from a spherical coordinate system to a Cartesian coordinate system or from a Cartesian coordinate system to a spherical coordinate system is possible in a simple manner.

[0057] The positional deviation is determined by subtraction from the actual position value and the setpoint position value .sub.S. The positional deviation is passed on to a multiplier 12 as an input variable. Together with a predeterminable calculation factor B, this determines a setpoint speed .sub.S. The calculation factor B can be determined from a remaining fraction of a transfer time specified for carrying out the entire transfer from the start position to the end position; in particular, it can be the value of this fraction. The multiplier 12 then multiplies this calculation factor B by the positional deviation and outputs the setpoint speed .sub.S, which is thus in a linear relationship to the positional deviation with the calculation factor B as a linear factor. This setpoint speed .sub.S corresponds to the speed at which the actual position value would have to be constantly moved in the direction of the setpoint position value .sub.S in order to be brought into line with it within the transfer time. If the transfer time has already elapsed, the multiplier 12 can output a stored maximum achievable speed for the movement of the trolley pole 2 by the actuators as the setpoint speed .sub.S.

[0058] When determining this setpoint speed .sub.S, the avoidance of overshoot is not initially considered, so that overshoot could occur as described in connection with FIG. 2 if this setpoint speed .sub.S were simply used for transfer.

[0059] To counteract overshooting, the positional deviation is also used for dynamic limitation via a maximum permissible speed .sub.max. In an absolute value element 11.1, the absolute value of the positional deviation is first determined so that the rest of the procedure can be carried out regardless of whether the position setpoint value .sub.S assigned to the end position 4 is greater or less than the actual position value of the current position of the trolley pole 2.

[0060] The absolute value element 11.1 can be part of the downstream control component that determines the maximum permissible speed .sub.max, which in the example shown is designed as lookup table 11. Different maximum permissible speeds are stored in the lookup table 11, which are assigned to individual positional deviations. The positional deviation determined from the actual position value and the setpoint position value .sub.S is compared with these stored positional deviations. Depending on the comparison result, the maximum permissible speed .sub.max is selected from the stored maximum permissible speeds or determined by interpolation between the stored maximum permissible speeds whose stored positional deviations come closest to the positional deviation . The values of the maximum permissible speed stored in the lookup table 11 can also decrease with decreasing values of the positional deviations assigned to them. In this way, the lookup table 11 determines increasingly smaller maximum permissible speeds .sub.max the closer the actual position value approaches the setpoint position value .sub.S, i.e. the smaller the positional deviation becomes.

[0061] As an alternative to the lookup table 11, in which individual value pairs of positional deviations and maximum speeds or positional deviation ranges and their associated maximum speeds are stored, a calculation element can be used in which a function is used to calculate the maximum permissible speed .sub.max as a function of the positional deviation . This function can be designed in such a way that the maximum permissible speed .sub.max also decreases with decreasing positional deviations , in particular in a non-linear ratio.

[0062] The increasingly smaller values of the maximum permissible speed .sub.max with decreasing positional deviations enable a dynamic limitation in which a stronger limitation occurs for smaller positional deviations than for larger positional deviations .

[0063] The determined maximum permissible speed .sub.max is forwarded to a limiting element 14 together with the setpoint speed .sub.S. As the sign of the setpoint speed .sub.S depends on whether the actual position value is to be transferred from a start position value Po above or below the setpoint position value .sub.S to the setpoint position value .sub.S, the maximum permissible speed .sub.max is also fed to the limiting element 14 as an input variable via an inverter 15. As the maximum permissible speed .sub.max, as well as the value of the maximum permissible speed .sub.max inverted by the inverter 15, is thus fed to the limiting element 14, which therefore in fact specifies a minimum value of a permissible speed in the negative range, a speed window of permissible speeds is specified for the limiting element 14.

[0064] For dynamic limitation, the limiting element 14 now compares the setpoint speed .sub.S to be limited and the maximum permissible speed .sub.max with each other. If the setpoint speed .sub.S is outside the speed window specified by the maximum permissible speed .sub.max, the maximum permissible total speed .sub.max is output as the dynamically limited setpoint speed .sub.B by the limiting element 14. However, if the setpoint speed .sub.S is within the speed window, the value of the setpoint speed .sub.S is output by the limiting element 14 as the value of the dynamically limited setpoint speed .sub.B and used in the following. Due to this dynamic limitation, which depends on the positional deviation of the actual position value from the setpoint position value .sub.S, comparatively large dynamically limited setpoint speeds are still permitted at the start of the transfer in the event of large positional deviations , while a stronger dynamic limitation and thus increasingly smaller dynamically limited setpoint speeds .sub.B are permitted as the positional deviation decreases towards the end of the transfer in order to avoid overshooting beyond the setpoint position value .sub.S.

[0065] Parallel to determining the dynamically limited setpoint speed .sub.B, the actual speed is determined from the actual position value and a time signal t by a derivation element 13. The time signal t can correspond to a cycle time that the control unit requires to run through a control cycle. Both the actual speed and the dynamically limited setpoint speed .sub.B are passed on as input signals to a subtraction element 16, which determines a speed difference .

[0066] The speed difference is forwarded to a PI controller 17, which uses it to determine a manipulated variable A used to swivel the trolley pole 2. The subtraction element 16 and the PI controller 17 form a proportional-integral control system with the dynamically limited setpoint speed .sub.B and the actual speed as input variables and the manipulated variable A as output variable.

[0067] In particular, in a current collector system 1 with pneumatic actuators 18, the manipulated variable can be the pneumatic pressure used to swivel the trolley pole 2 around one of the axes 5, 6. The manipulated variable A causes a change in the position of the trolley pole and thus a change in the actual position value .sub.S. After the manipulated variable A is output, the actual position value is therefore recorded again, so that the control steps described above are run through cyclically until the actual position value corresponds to the setpoint position value .sub.S when the trolley pole 2 is at rest.

[0068] The method described above for automatically transferring a swiveling trolley pole 2 from a start position 3 to an end position 4 and the current collector system 1 enable a reliable and time-saving transfer of the trolley pole 2.

LIST OF REFERENCE SYMBOLS

[0069] 1 Current collector system [0070] 2 Trolley pole [0071] 2.1 End [0072] 2.2 End [0073] 3 Start position [0074] 4 End position [0075] 5 Axis [0076] 6 Axis [0077] 10 Control unit [0078] 11 Lookup table [0079] 11.1 Absolute value element [0080] 12 Multiplier [0081] 13 Derivation element [0082] 14 Limiting element [0083] 15 Inverter [0084] 16 Subtraction element [0085] 17 PI controller [0086] 18 Actuator [0087] 100 Trolleybus [0088] 110 Vehicle roof [0089] 200 Overhead line [0090] .sub.0 Start position value [0091] Actual position value [0092] .sub.S Setpoint position value [0093] .sub.U Overshoot position [0094] Positional deviation [0095] Actual speed [0096] .sub.S Setpoint speed [0097] .sub.B Dynamically limited setpoint speed [0098] .sub.max Maximum permissible speed [0099] Speed difference [0100] A Manipulated variable [0101] B Calculation factor [0102] t Time

[0103] Having described the invention in detail and by reference to the various embodiments, it should be understood that modifications and variations thereof are possible without departing from the scope of the claims of the present application.