DE-102016221477-B4 - Device for operating and determining the operating state of an electromagnetic actuator, as well as coupling device and motor vehicle drivetrain

DE102016221477B4DE 102016221477 B4DE102016221477 B4DE 102016221477B4DE-102016221477-B4

Abstract

Device for operating and determining an operating state, in particular an actuator temperature and/or an actuator position, of an electromagnetic actuator (1), in particular a linear actuator, wherein a two-point controller (12) for operating the actuator (1) and a detection means (11C) configured to determine a time course of the control signal (H1) output by the two-point controller (12) and to determine the operating state from this, is provided, characterized in that the two-point controller is configured to reduce power for operating the actuator when an actuator temperature exceeds a limit value, so that continued operation of the device with reduced input power is possible.

Inventors

Florian Weinl
Martin Ruider
Michael Pantke
Thomas Speh
Thomas Schwegler
Lothar Kiltz

Assignees

ZF FRIEDRICHSHAFEN AG

Dates

Publication Date: 20260513
Application Date: 20161102

Claims (10)

Device for operating and determining an operating state, in particular an actuator temperature and/or an actuator position, of an electromagnetic actuator (1), in particular a linear actuator, wherein a two-point controller (12) for operating the actuator (1) and a detection means (11C) configured to determine a time course of the control signal (H1) output by the two-point controller (12) and to determine the operating state from this, is provided, characterized in that the two-point controller is configured to reduce power for operating the actuator when an actuator temperature exceeds a limit value, so that continued operation of the device with reduced input power is possible.
Device according to Claim 1 , where the two-point controller (12) is an analog two-point controller.
Device according to Claim 2 , wherein the two-point controller (12) is implemented discretely in hardware.
Device according to one of the preceding claims, wherein the two-point controller (12) is provided with an upper current limit and a lower current limit by which it limits the electric current supplied to the actuator (1).
Device according to one of the preceding claims, wherein the determining means (11C) is configured to determine a value of the duty cycle and duty cycle of the control signal (H1) and to determine an actuator temperature from the one value of duty cycle and duty cycle.
Device according to one of the preceding claims, wherein the determining means (11C) is configured to determine a value of frequency and period of the control signal (H1) as well as to determine the electric current supplied to the actuator (1) and to determine an actuator position (1) from a value of the frequency and period as well as from the current.
Device according to one of the preceding claims, wherein the determining means (11C) is configured to include a supply voltage of the actuator (1) in the determination of the operating state.
Device according to one of the preceding claims, wherein the detection means (11C) comprises a lookup table or a characteristic map or another mathematical function and is configured to determine the operating state of the actuator (1) herewith and with the control signal (H1).
Coupling device (2) with a coupling means (7) for selectively mechanically connecting and disconnecting two components (8, 9) and an electromagnetic actuator (1) for moving the coupling means (7), characterized by a device for operating and determining an operating state of the actuator (1) according to one of the preceding claims.
Motor vehicle powertrain, characterized by a coupling device (2) according Claim 9 .

Description

The invention relates to a device for operating and determining the operating state of an electromagnetic actuator. The invention also relates to a coupling device comprising a coupling means for selectively mechanically connecting and disconnecting two components, and an electromagnetic actuator for actuating the coupling. The invention further relates to a motor vehicle powertrain with such a coupling device. Electromagnetic actuators are used to perform positioning tasks, for example, to actuate clutches in automotive transmissions. Knowing the current actuator position (the position the actuator occupies) is often crucial for control strategies and safety concepts. Furthermore, knowing the actuator's temperature is frequently necessary, for example, for condition monitoring. External sensors are often used for this purpose. However, the complexity of external sensors is high. They require installation space, integration is difficult, wiring must be considered, and the sensor signal typically needs to be converted into a digital signal. Moreover, the tolerances of the components involved introduce inaccuracies. By utilizing so-called inherent measurement effects within electromagnetic actuators, external sensors can be eliminated. Methods for the inherent state detection of electric motors are well-known. Solutions for state detection in electromagnetic linear actuators or similar magnetic actuators are less widely known. For these actuators, external displacement measuring systems or proximity sensors are therefore usually used to detect the actuator position. The one in DE 102005018012 A1 The proposed concept of inherent position detection is based on the choke coil principle. In the case of the DE 102007034768 B3 The proposed concept utilizes the so-called hysteresis amplification. Out of DE 101 39 243 A1 A method for monitoring an electromagnetically operated actuator with a first control unit controlled coil for actuating the actuator is described. US 5914 849 A reveals a control circuit of a DC actuator. DE 10 2007 034 768 B3 shows an electric lifting magnet, where, in the case of a pulsed current supply to the lifting magnet, the pulse frequency correlates with the lifting position of the lifting magnet. The object of the present invention is to improve the state of the art. This problem is solved by the features specified in the main claims. Preferred embodiments thereof are described in the dependent claims. Accordingly, a device for operating an electromagnetic actuator and determining its operating state is proposed. The device comprises a two-position controller for operating the actuator and a determination mechanism. This mechanism is designed to determine the temporal profile of a control signal output by the two-position controller and to derive the operating state from this profile. In particular, the dynamics of the control signal are determined for this purpose. The device is designed to supply an electric current, hereinafter also referred to as "actuator current," to the actuator based on the control signal. Corresponding to the temporal profile of the control signal, a characteristic temporal profile of the actuator current develops. This profile inherently contains the operating state of the actuator, as it essentially determines the rate at which the actuator current builds up and falls away, as well as its maximum and average magnitude. It has now been recognized that, due to the characteristic control behavior of a two-point controller, the operating state of the actuator is also reflected in the control signal itself. The temporal profile of the actuator current is, in fact, reflected in the control signal. The invention utilizes this finding and accordingly uses the control signal of the two-point controller to deduce the operating state of the actuator very simply and accurately. The electromagnetic actuator is, in particular, an electromagnetic linear actuator. The electromagnetic actuator can, in particular, have at least or exactly one coil. This coil(s) allows the actuator's armature to be magnetically moved. This movement can be detected at the actuator and used mechanically as a positioning movement of the actuator. The actuator position corresponds to a position of the armature within the actuator or to a positioning position that the actuator assumes externally. The device can, in particular, measure the actuator temperature and/or a The actuator's position can be determined. This then defines the desired operating state of the actuator. The proposed concept offers the advantage that only minimal resources are needed to obtain information about the actuator's current operating state. This information can be immediately processed, for example, to control or regulate the actuator. By utilizing the actuator's integrated sensor capabilities, the tolerance chain can be shortened compared to the external sensors typically used. Preferably, the two-point controller is an ana