CN115776266A

CN115776266A - Method and device for operating an automatic control system of a motor vehicle

Info

Publication number: CN115776266A
Application number: CN202211091927.1A
Authority: CN
Inventors: C·施托尔茨; J·卡萨格兰德
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2021-09-07
Filing date: 2022-09-07
Publication date: 2023-03-10
Also published as: DE102021209836A1

Abstract

The invention relates to a method for operating an adjustment system (2) and to an adjustment system (2), in particular a sun roof system or a window lift system, in a motor vehicle, wherein an adjustment element (3) can be moved in a translatory manner by means of a servomotor (8), comprising the following steps: -operating the servomotor (8) using the speed regulation; -monitoring the rotational speed (n) of the servomotor (8), wherein the rotational speed (n) is found to be below a regulation-off threshold (n) _abschalt ) The speed regulation is deactivated and a protective operating mode is used, whichIn the protective operating mode, the servomotor (8) is operated with a predetermined motor torque (M) to be set, the lower the rotational speed (n) is, the lower the motor torque is.

Description

Method and device for operating an automatic control system of a motor vehicle

Technical Field

The present invention relates to an adjustment system, such as an opening and closing system of a motor vehicle, in particular an automatic sun roof system, a window lift system or a seat adjustment system. The invention also relates to measures for protecting the mechanism in the event of a crash of the adjusting element into the end position or in the event of a blockage in the adjusting range.

Background

Automatic adjustment systems for vehicles are applied to automatic window regulator systems and automatic sunroof systems. These systems are capable of opening and closing a corresponding vehicle opening by moving a corresponding adjustment element, such as a window pane or a sunroof.

For moving the adjusting element, the adjusting element is coupled to the servomotor via an adjusting mechanism. In general, the adjusting mechanism converts a rotary movement of the servomotor into a translatory adjusting movement of the adjusting element. Usually, the servomotor is operated with a rotational speed regulation in order to achieve a movement of the regulating element which is as uniform as possible.

When the adjusting element is moved, it is moved in the end position of the possible path of movement onto the corresponding end stop. Since, when reaching this end stop, the motor current increases significantly to a maximum torque as a result of an increase in the control deviation due to the operation of the servomotor in the manner of speed control, a high blocking torque is effective at the point in time when the control element stops at the end stop. This results in a high force in the adjusting mechanism, on the adjusting element and on the end stop. The relevant components of the control system must therefore be designed to be correspondingly robust in order to be able to withstand the torques which arise as a result of the corresponding design of the servomotor.

It is therefore an object of the present invention to provide an adjusting system in which the mechanical stress of the adjusting mechanism and of the end stop when the adjusting element reaches the end position is reduced.

Disclosure of Invention

According to the invention, a method for operating an adjustment system of a motor vehicle, in particular a window lift system or a sunroof system, according to claim 1, and an adjustment system for a motor vehicle according to the independent claims are provided.

Further embodiments are specified in the dependent claims.

According to a first aspect, a method for operating an adjustment system, in particular a sun roof system or a window lift system, in a motor vehicle is provided, wherein an adjustment element can be moved in a translatory manner by means of a servomotor, the method having the following steps:

-operating the servomotor using the speed regulation;

monitoring the rotational speed of the servomotor, wherein the rotational speed control is deactivated when the rotational speed is found to be below a control switch-off threshold, and a protected mode of operation is used, wherein in the protected mode of operation the servomotor is operated with a predefined motor torque to be set, the lower the rotational speed, the lower the motor torque.

When this rotational speed is found to exceed the regulation switch-off threshold, the rotational speed regulation can be activated again and the protected operating mode can be exited.

Servomotors for automatic adjustment systems in motor vehicles, such as sunroof systems or window lift systems, are usually operated by means of a simple rotational speed adjustment. In this case, the actuating element, i.e. the window pane or the sun roof, is moved at a constant actuating speed by adjusting the rotational speed of the corresponding servomotor. The rotational speed adjustment can compensate for the changing friction of the adjusting element during the movement in its corresponding guide device, so that a smooth, jitter-free opening and closing of the respective vehicle opening can be achieved.

When the end stop is reached, i.e., for example, in the case of an opening and closing system, either the open position or the closed position, the actuating element strikes the damping element and is thereby braked. As a result, the rotational speed control is saturated by the reduction in the rotational speed and the resulting control deviation, wherein in particular the servomotor is controlled in such a way that the motor current is maximized and thus a maximum torque is provided by the drive motor. This maximum torque is effective in the case of a rapid reduction in the rotational speed and is a high load for all components of the control system, in particular when the control element strikes an end stop.

In this connection, the above method provides for: the speed regulation for the servomotor is exited below a regulation-off threshold, which is determined by a threshold speed below the target speed of the regulated operation, and a protected operating mode is used. In the protection operating mode, the rotational speed is monitored and the set motor torque or the set motor current is limited depending on the rotational speed, so that the motor torque decreases as the rotational speed decreases. If this rotational speed now drops further due to the impact of the actuating element on the end stop and becomes zero, the now effective motor torque is reduced relative to the maximum motor torque, so that the mechanical load on the components of the actuating system is reduced.

Provision may also be made for: in the protection operating mode, protection rotational speed thresholds are defined, wherein the motor torque to be set is reduced if the rotational speed falls below one of the protection rotational speed thresholds, wherein the motor torque to be set is increased if the rotational speed exceeds one of the protection rotational speed thresholds.

In particular, it can be provided that: in the protected operating mode, rotational speed ranges are defined, for which the motor torques to be set are each specified.

The torque to be set can be reduced by a predetermined relative or absolute value for each of these rotational speed ranges in the direction of decreasing rotational speed, wherein in particular the motor torque to be set for the rotational speed range of this rotational speed adjacent to 0 corresponds to 80% to 90% of the maximum settable motor torque.

One or more protective rotational speed thresholds can thus be defined, which specify the motor torque to be set or the motor current to be set for different rotational speed ranges below the threshold rotational speed, respectively, wherein the lower the rotational speed range, the lower the motor torque to be set or the motor current to be set. Thus, as the motor rotation speed decreases, the motor torque can be gradually reduced after the undershoot.

Furthermore, the servomotor can be controlled by means of pulse width modulation, wherein the motor torque to be set is specified as the motor current to be set.

The setting of the motor current is usually effected by specifying a motor voltage which can be set in particular by means of a pulse width modulation method according to a specified duty cycle. The duty cycle describes the voltage as part of the supply voltage and determines the motor current and thus the motor torque provided by the servomotor from the effective voltage generated at the servomotor. That is, if, in the case of the above-described speed regulation, the duty ratio as the manipulated variable of the regulation reaches a maximum value of, for example, 95% to 98%, and the speed drops below the regulation-off threshold, the speed regulation is deactivated and the protected operating mode is used. In the case of a rotational speed corresponding to this regulation-off threshold, in the protection operating mode, the maximum value of the duty cycle is initially maintained. In the guard operation mode, the rotation speed is monitored and the set duty ratio is limited according to the rotation speed, so that the motor torque decreases as the rotation speed decreases. If the rotational speed now drops further and becomes zero as a result of the impact of the actuating element on the end stop, the now acting motor torque is reduced relative to the maximum motor torque, so that the mechanical loading to which the components of the actuating system are subjected is reduced.

The protective rotational speed threshold is now defined as rotational speed limits, which can be defined, for example, as a function of the target rotational speed on which the rotational speed adjustment is based. In this way, for example, a first protective rotational speed threshold is provided at 50% of the target rotational speed, wherein the maximum duty cycle, i.e. the maximum motor current, is reduced by a relative or absolute value, such as by 5% of the original maximum duty cycle or motor current. Other protection thresholds may be provided, for example in the case of 45%, 40% of the target rotational speed, wherein the duty cycle or motor current is further reduced. Thus, when the rotational speed of the servomotor becomes zero, the blocking torque is significantly lower than the blocking torque that would have been present at the maximum duty cycle or maximum motor current, for example, when the rotational speed regulation was exited, so that the mechanical load to which the components of the regulation system were subjected is significantly reduced.

The method can realize that: the robustness of the mechanical components of the control system is reduced in the design phase, since the load reduction is caused by the operating situation in which the control element drives against the end stop, in which the highest load on the components of the control system is present. In the case where a plurality of protective rotation speed thresholds are provided, the motor torque can be gently reduced, so that a chattering caused by an excessive sudden reduction in the motor torque can be avoided.

The above-described method enables the provision of a corresponding control unit which can be used for a plurality of different types of servomotors, so that the implementation can be used for various adjustment systems, irrespective of the choice of the type of drive motor.

According to another aspect, an adjustment system, in particular a sunroof system or window lift system, in a motor vehicle is provided, comprising:

a servomotor coupled with the adjusting element via an adjusting mechanism;

-a control unit designed to:

o operating the servomotor using the speed regulation,

monitoring the rotational speed of the servomotor, wherein a protected mode of operation is used when the rotational speed is found to be below the regulation switch-off threshold, wherein in the protected mode of operation the servomotor is operated with a predetermined, in particular constant, motor torque to be set, the lower the rotational speed, the lower the motor torque.

Drawings

Embodiments are subsequently explained in more detail on the basis of the enclosed drawings. Wherein:

fig. 1 shows a schematic view of an opening and closing system in the case of a sunroof system of a motor vehicle;

FIG. 2 shows a flow chart for explaining a method for operating the regulating system of FIG. 1; and

fig. 3 shows a diagram for elucidating the reduction of the motor torque in the case of a low motor speed.

Detailed Description

Fig. 1 shows a schematic view of a sun roof system 2 as an adjusting system of a motor vehicle 1 with a sun roof as an adjusting element 3, which sun roof can be moved in a guide device 4 between an open position and a closed position. Here, the window can be moved onto a first end stop 5, wherein the window is completely closed, and the window can be moved onto a second end stop 6, wherein the window is completely open.

The sun roof is coupled via an adjusting mechanism 7 to a servomotor 8, so that when the servomotor 8 is activated, a corresponding motor torque acts on the adjusting mechanism 7 and a corresponding adjusting force is exerted on the sun roof 3. Here, the rotary movement of the servomotor 8 is converted into a translatory movement of the sun roof 3. Here, depending on the rotational direction of the servomotor 8, the sunroof 3 is moved in the opening or closing direction.

The servomotor 8 can be arranged, for example, as a brush-commutated electric motor. The variable actuation of the servomotor 8 can be achieved, for example, by variable regulation of the motor voltage. For this purpose, the servomotor 8 can be coupled to a power driver 9, which reduces the specified supply voltage by means of a pulse-width-modulated control method.

The supply voltage can be connected to the servomotor 8, in particular, via a power semiconductor switch. A control unit 10 is also provided, which switches the power driver 9 and controls the pulse width modulation of the power driver 9 according to the duty cycle. In the case of pulse width modulated actuation, the duty cycle specifies an effective motor voltage or an effective phase voltage, which determines the motor current and thus the motor torque. The servomotor 8 may also be equipped with a rotational speed sensor 11, which transmits a rotational speed signal to the control unit 10. Alternatively, sensorless rotational speed detection may also be used.

The control unit 10 is designed to drive the servomotor 8 in the corresponding rotational direction upon a request to open or close the sunroof system 2, in particular by activating a rotational speed adjustment. The request for adjusting the roof window 3 can be made automatically or also by a user input at the operating element 12. The rotational speed adjustment uses a specified target rotational speed so that uniform movement of the sunroof 3 can be achieved in this way.

A flow chart illustrating a method for operating the sunroof system 2 by means of the control unit 10 is shown in fig. 2. The method can be implemented in the control device 10 in the form of software and/or hardware algorithms.

In step S1, it is first checked whether the sunroof 3 should be moved in the opening or closing direction. The activation of the movement of the roof window 3 can be effected by actuation of the actuating element 12 or by automatic signaling. If this is the case (option: yes), the method is continued with step S2, otherwise a jump is made back to step S1.

In step S2, a speed control is activated, in particular after the start, which specifies the target speed n _soll . For example, the target rotational speed may be 80 revolutions per minute. The rotational speed control can be designed in the form of a conventional rotational speed control, in particular as a PID controller. The rotational speed control is controlled in response to a control deviation between the target rotational speed and the rotational speed measured by the rotational speed sensor 11, and a duty ratio for pulse width modulation is provided as an operating variable which specifies the motor voltage. The duty cycle is converted into a corresponding pulse control signal which is applied to the control input of the semiconductor switch of the power driver 9 in order to thus apply or disconnect a supply voltage to or from the servomotor 8 depending on the pulse width of the control signal. Thereby, an effective motor voltage is obtained, which results in a resulting motor current, which is substantially proportional to the motor voltage. The motor current determines the set motor torque in a linear manner.

In step S3, it is checked whether the rotational speed is within a specified regulation range around the target rotational speed. The regulating range can be adjusted by regulating the turn-off threshold n _abschalt Limited downwards, the regulation-off threshold may be specified between 60-90% of the target speed. If the rotational speed is within the specified control range around the target rotational speed (option: yes), the method is continued with step S2, otherwise (option: no) the method is continued with step S4.

In step S4, it is checked whether the specified maximum duty cycle is reached. The specified maximum duty cycle may be between 95% and 97% and represents the maximum possible handling or the maximum possible motor voltage. If the maximum duty cycle is reached (option: yes), the method is continued with step S5, otherwise (option: no) a jump is made back to step S2.

In step S5, the regulation is ended, the protection operating mode is adopted and the duty cycle to be set is fixedly set. The duty cycle to be set initially corresponds to this maximum duty cycle.

At 0 and a regulation turn-off threshold n _abschalt The rotational speed range in between is divided into a plurality of rotational speed ranges, which are subdivided by one or more protective rotational speed thresholds. As the rotational speed decreases, the duty ratio to be set, which is allocated to these rotational speed ranges, decreases.

In step S6, it is checked whether the rotational speed is below one of the protective rotational speed thresholds. If this is the case (option: yes), the duty cycle to be set is reduced by a predetermined value or set to the duty cycle assigned to the relevant speed range, otherwise (option: no) the method continues with step S10.

In step S10, it is checked whether the rotational speed exceeds one of the protective rotational speed thresholds. If this is the case (option: yes), the duty cycle to be set is increased by a predetermined value or set to the duty cycle assigned to the relevant speed range and the method is continued in step S7, otherwise (option: no) the method is continued in step S5.

In step S7, the servomotor 8 is operated according to the duty ratio to be set.

In step S8, it is checked whether the rotational speed has reached zero. If this is the case (option: no), the servomotor 8 is switched off in step S11, since the end stop has been reached or there is another blockage of the sun roof 3, and the method continues with step S1. Otherwise, the method continues with step S9.

In step S9, it is checked whether there is still a request for activating the sunroof 3. If this is the case (option: yes), the method is continued with step S12, otherwise (option: no) a jump is made back to step S1.

In step S12, it is checked whether the rotational speed n again exceeds the regulation-off threshold n _abschalt . If this is the case (option: yes), the method is continued with step S2, otherwise (option: no) the method is continued with step S5.

Fig. 3 is a diagram showing an exemplary speed profile n and torque profile M over time t when using the above-described method for the case of operation with speed regulation and subsequent approach to an end stop. The active range R of the rotational speed regulation can be seen by a fluctuating setting intervention of the motor torque M to be set. When the rotation speed decreases at time T1, the motor torque M to be set becomes maximum. If the speed n drops further below the regulation-off threshold n _abschalt Then the maximum motor torque is set. When the speed n reaches a first protection threshold n _S1 The motor torque M to be set is correspondingly reduced by reducing the applied duty cycle or the motor voltage, which has a direct effect on the reduction of the motor speed n. Correspondingly, when the second protection threshold n is reached _S2 Thereafter, the motor torque M may be correspondingly further reduced by further reducing the applied duty cycle or the motor voltage. This can be done stepwise in steps, so that when the rotational speed n reaches zero, a blocking torque is achieved which can be significantly reduced in relation to the maximum motor torque which would be reached with the maximum duty cycle. Immediately after the blockage is found, the motor torque to be set is reduced to 0.

Claims

1. Method for operating an adjustment system (2), in particular a sun roof system or a window lift system, in a motor vehicle, wherein an adjustment element (3) can be moved in a translatory manner by means of a servomotor (8), having the following steps:

-operating the servomotor (8) using a rotational speed regulation;

-monitoring the rotation speed (n) of the servomotor (8), wherein the rotation speed (n) is found to be below a regulation-off threshold (n) _abschalt ) The speed regulation is deactivated and a protected operating mode is used, wherein in the protected operating mode the servomotor (8) is operated with a predefined motor torque (M) to be set for the regulating element (3), the lower the speed (n) the lower the motor torque.

2. Method according to claim 1, wherein in the protection operating mode a protection rotational speed threshold is defined, wherein the motor torque (M) to be set is reduced when the rotational speed (n) falls below one of the protection rotational speed thresholds, wherein the rotational speed exceeds the protection rotational speed threshold (n), respectively _S1 、n _S2 ) In one case, the motor torque (M) to be set is increased.

3. Method according to claim 1 or 2, wherein in the protective operating mode a rotational speed range is defined for which the motor torque (M) to be set is specified, in particular constant, in each case.

4. A method according to claim 1 or 2, wherein the lower the rotation speed (n) of the rotation speed range, the lower the motor torque (M) to be set is selected.

5. Method according to one of claims 1 to 4, wherein the torque (M) to be set is reduced by a predetermined relative or absolute value in each case for the rotational speed range in the direction of a reduction of the rotational speed (n), wherein in particular the motor torque (M) to be set corresponds to 80% -90% of the settable maximum motor torque for a rotational speed range of the rotational speed (n) adjoining 0.

6. Method according to one of claims 1 to 5, wherein the servomotor (8) is controlled by means of pulse width modulation, wherein the motor torque (M) to be set is specified as the motor current to be set.

7. Method according to any one of claims 1 to 6, wherein the rotational speed is found to exceed the regulation-off threshold (n) _abschalt ) The speed regulation is activated and the protected mode of operation is exited.

8. Device, in particular control unit (10), for controlling an adjustment system (2), in particular a sunroof system or a window lift system, in a motor vehicle, wherein the device is designed for:

-operating the servomotor (8) using speed regulation;

-monitoring the rotation speed (n) of the servomotor (8), wherein the rotation speed (n) is found to be below a regulation-off threshold (n) _abschalt ) A protected operating mode is used, in which the servomotor (8) is operated with a predefined motor torque (M) to be set, the lower the rotational speed (n) is, the lower the motor torque is.

9. An adjustment system (2), in particular a sunroof system or a window lift system, in a motor vehicle, the adjustment system comprising:

-a servomotor (8) coupled with the adjusting element (3) via an adjusting mechanism (7);

-a control unit (10) designed for:

o operating the servomotor (8) using speed regulation,

o monitoring the rotational speed (n) of the servomotor (8), wherein the rotational speed (n) is found to be below a regulation-off threshold (n) _abschalt ) A protected operating mode is used, in which the servomotor (8) is operated with a predefined motor torque (M) to be set, the lower the rotational speed (n) the lower the motor torque.

10. Adjustment system (2) according to claim 9, wherein an end stop is provided for the adjustment element (3) in order to block the servomotor (8) when the adjustment element (3) hits the end stop.