Method and related equipment for transmitting data from an actuator to a control device

Abstract

This invention relates to a method and related apparatus for transmitting data from an actuator to a control device. Specifically, this invention relates to a method for transmitting data from an actuator (2) to a control device (1) that operates the actuator (2), wherein the control device (1) operates a piezoelectric element (3) contained in the actuator (2), wherein, for transmitting data in the actuator (2), a load (7) is connected in parallel with or not in parallel with the piezoelectric element (3).

Description

Technical Field

[0001] This invention relates to a method for transmitting data from an actuator to a control device, and to a corresponding actuator and a corresponding control device. An actuator is known whose characteristics are determined at the end of production and are represented as corresponding data on its outer surface using a dot matrix. Upon startup, an assembly worker reads the corresponding data from the dot matrix and transmits the data to the control device. Summary of the Invention

[0002] Advantages of the present invention

[0003] In contrast, the method according to the invention, or the actuator or control device according to the invention, has the following advantages: data is automatically transmitted from the actuator to the control device via electrical signals. Therefore, it is no longer necessary to read the dot matrix and transmit it to the control device. This is especially beneficial when combining the actuator and the control device, eliminating manual operation steps.

[0004] According to a method of transmitting data from an actuator to a control device that operates the actuator, wherein the control device operates a piezoelectric element contained in the actuator, and a load is connected in parallel with the piezoelectric element, or not connected in parallel, for transmitting the data in the actuator. A predetermined first voltage difference is applied to the piezoelectric element by the control device for operation, and a predetermined second voltage difference is applied to the piezoelectric element for transmitting the data, wherein the second voltage difference is selected to avoid operation of the actuator. Preferably, the second voltage difference applied by the control device is affected by connecting the load in parallel. The current required to apply the second voltage difference is determined both when the load is connected in parallel and when it is not connected in parallel. The first and second voltage differences have opposite signs. The actuator has control logic; information about the characteristics of the actuator is stored in the control logic; the information about the characteristics is transmitted to the control device using the data; and the control device uses the transmitted data to operate the actuator. The control logic device stores information about the characteristics of the actuator, which is determined by measuring these characteristics during the production of the actuator. The actuator according to the invention has a piezoelectric element for use according to the method described above, wherein a component is provided to connect the load in parallel with the piezoelectric element, or not in parallel, to transmit data. The invention also provides a control device for operating the aforementioned actuator, comprising a component for operating the piezoelectric element and other components that determine whether the load is connected in parallel with or not in parallel with the piezoelectric element, and thus receive data transmitted by the actuator. Data transmission is particularly simply requested by the control device using a second voltage difference, which is distinctly different from the first voltage difference used to operate the actuator. The second voltage difference is chosen to avoid operation of the actuator. Thus, unintentional operation of the actuator is reliably avoided. Verification of the parallel connection of the load is particularly simple by current measurement in the control device. Voltage levels are particularly simple to distinguish by polarity. Data transmitted by the actuator is used by the control device, particularly for operating the actuator. In this way, production fluctuations of the actuator can be taken into account when operating the actuator. When producing the actuator, the corresponding data can be determined very simply. Attached Figure Description

[0005] Embodiments of the invention are shown in the accompanying drawings and described in more detail in the following description.

[0006] Figure 1 A schematic circuit diagram of the control equipment and actuators is shown.

[0007] and Figure 2 An example of an alternative to the implementing agency is shown. Detailed Implementation

[0008] exist Figure 1 The diagram schematically illustrates control device 1 and actuator 2, showing only the relevant electronic components of control device 1 or actuator 2 respectively. Figure 1 In the diagram, components of the control device 1 are shown to the left of the dashed dividing line 12, and components of the actuator 2 are shown to the right of the dashed dividing line 12. The actuator 2 is an actuator with a piezoelectric element 3. This piezoelectric element 3 is a mechanical actuator that undergoes a length change due to an applied voltage. This length change can be directly used as a mechanical actuator. Such an actuator is used, for example, as a valve for metering the injection of liquid (e.g., fuel) into an engine.

[0009] The piezoelectric element 3 is operated by the control device 1 by correspondingly manipulating MOS-FET transistors 21, 22, and 24, which are configured as switches. Alternatively, switches 21, 22, and 24 can also be formed using other transistors, such as IGBTs. Through switch 21, the first terminal 31 of the piezoelectric element 3 is connected to the high-voltage terminal 33 of the control device 1. A voltage difference of, for example, 250V is applied to the high-voltage terminal 33 of the control device 1 relative to the ground terminal 34. Through switch 22, the first terminal 31 of the piezoelectric element 3 is connected to the ground terminal 34 of the control device 1. By alternately switching switches 21 and 22, the terminal 31 of the actuator 2 or the piezoelectric element 3 can thus be selectively connected to a control voltage of 250V or ground, thereby causing the piezoelectric element 3 to contract and re-expand. The second terminal 32 of the piezoelectric element 3 is connected to the ground terminal 34 of the control device 1 via switch 24. During operation of actuator 2 or piezoelectric element 3, switch 24 is switched on, and second terminal 32 is thus connected to ground terminal 34. Actuator 2 can therefore be controlled by switching transistors or switches 21, 22, and 24 via the corresponding program in control device 1.

[0010] According to the program stored in the control device 1, the piezoelectric element 3 can be manipulated, and thus the actuator 2 can be operated. A problem with such control of the actuator 2 via the control device 1 is the variation in the characteristics of the actuator 2 caused by production. To compensate for such variation, it is desirable that the control device 1 contains information regarding the variation in the characteristics of the actuator 2. During the production of the actuator 2, its characteristics can be determined at the end of production, and these characteristics can be used to control the piezoelectric element 3. Figure 1 In this embodiment, the actuator 2 has a control logic device 9, which internally includes a memory storing information about variations in the characteristics of the actuator. Furthermore, the actuator 2 has other components that enable the transmission of information stored in the control logic device 9 back to the control device 1.

[0011] A load 7 is arranged in parallel with piezoelectric element 3 in a series circuit with switch 23, which is configured as a transistor. By switching switch 23 to the ON position, load 7 can thus be connected in parallel with piezoelectric element 3. Switch 23 is configured as a transistor, such as a MOS-FET or IGBT, and is controlled by control logic device 9 via control lines. By a corresponding signal from control logic device 9, switch 23 can be placed in an ON state or a OFF state.

[0012] Furthermore, the actuator 2 also has a voltage supply device 10, which, in addition to the regulator 15, includes several capacitors for stabilizing the regulated voltage. As long as the control device 1 applies a voltage signal to the actuator 2 frequently enough, the voltage supply device 10 ensures a sufficient voltage supply to the control logic device 9. Even if the control device 1 does not apply a voltage signal to the actuator 2 for a short period, the voltage supply device 10 still ensures a supply voltage to the control logic device 9.

[0013] In addition, the control logic device 9 has three external terminals 13 for externally programming or storing data. For this purpose, information about the characteristics of the actuator 2, determined during its production, is stored in the control logic device 9 via the terminals 13. A supply voltage is applied to one of the terminals 13, ground is applied to another terminal 13, and corresponding data signals are applied to the other terminals 13.

[0014] By applying a second voltage difference to actuator 2, control device 1 can cause data to be transmitted from actuator 2 or its control logic device 9 to control device 1. Preferably, the second voltage difference has the opposite sign to the first voltage difference. To this end, control device 1 first disconnects switch 24, so that terminal 32 of actuator 2 is no longer connected to ground. Furthermore, switch 21 is opened, so that terminal 31 of actuator 2 is no longer connected to terminal 33, to which a high voltage of 250V is applied. Switch 22 is switched on, so that terminal 31 remains connected to ground. Furthermore, switch 25 is switched on. For example, a supply voltage of 6V is applied to terminal 39, which, together with operational amplifier 35, forms a constant voltage source. For this purpose, the input and output terminals of operational amplifier 35 are connected. With switch 25 closed, a constant voltage is thus supplied to terminal 32 of actuator 2. The voltage at terminal 32 is estimated to be so low that it does not cause any noticeable adjustment movement of actuator 2. The voltage supply device 10 is activated by diode 36, thus enabling the control logic device 9 to operate. The activated control logic device 9 then generates corresponding control pulses for switching switch 23, through which resistor 7 is connected in parallel with piezoelectric element 3. Due to this parallel connection, the current flow through the constant voltage source formed by operational amplifier 35 is loaded with different currents depending on whether resistor 7 is connected in parallel. This current can be verified by the voltage drop across resistor 37, which is located between the output of operational amplifier 35 and switch 25, verified by operational amplifier 38. For this purpose, the two inputs of operational amplifier 38 are connected before and after resistor 37. Correspondingly, a signal is output at the output of operational amplifier 38 corresponding to the connection state of load 7 or the switching state of switch 23. The output signal of operational amplifier 38 can then be processed in the corresponding software of control device 1 to process the value stored in control logic device 9. In this way, the corresponding values ​​that have been programmed into the control logic device 9 during the manufacturing of the actuator can be transmitted to the control device 1.

[0015] In particular, the method according to the invention can be used when the defined characteristics of the actuator 2 deviate from each other due to variations in production. For example, the actuator 2 can be designed as a valve for injecting liquid, and the amount of liquid injected by the valve may vary due to production fluctuations under the same applied control signal. For example, such a valve can be used to inject fuel into an internal combustion engine. Such variations in the valve can then be identified at the end of production by test injection and corresponding measurements, and the corresponding parameters describing this are then stored in the logic circuit 9. For this purpose, the logic circuit 9 has an external terminal 13 through which the logic module 9 can be activated, and thus the corresponding measurement data can be programmed. If the actuator 2 then operates together with the control device 1, this data stored in the control logic device 9 is transmitted from time to time during initial startup or, but also during continuous operation. In this way, negative effects caused by production fluctuations can be avoided when manufacturing the actuator.

[0016] exist Figure 2 The figure also shows alternative embodiments of the actuator 2 according to the invention. Reference numerals 31, 32, 36, 3, 23, 7, 10, 15, 9, and 13 are used to indicate the presence of the actuator 2 according to the invention. Figure 1 The same object with the same function as described. However, with Figure 1 Unlike other actuators, terminal 13 in actuator 2 is no longer externally accessible, or occupied by another function in its completed state. Therefore, data can be stored in control logic device 9 without using terminal 13. To store data in control logic device 9, in Figure 2 In this example, it is done by applying a voltage to terminal 32 that is different from the voltage that may exist between control device 1 and actuator 2 during normal operation, specifically a voltage higher than that that may exist between control device 1 and actuator 2 during normal operation. For example, if control device 1 applies a voltage of 6 volts to terminal 32, then for the purpose of storing data in control logic device 9, a voltage of 8 volts may be applied. The increased voltage is then also applied to the cathode of diode 36 and is identified by programming circuit 40 connected thereto. If the increased voltage is applied, the corresponding data word can be transmitted to programming circuit 40 by corresponding timing of the voltage signal between terminals 32 and 31, and the corresponding data word can be stored in control logic device 9 via line 41.

Claims

1. A method for transmitting data from an actuator (2) to a control device (1) that manipulates the actuator (2), wherein the control device (1) manipulates a piezoelectric element (3) contained in the actuator (2), characterized in that, In order to transmit the data in the actuator (2), the load (7) is connected in parallel with the piezoelectric element (3), or the load (7) is not connected in parallel. Through the control device (1), a predetermined first voltage difference is applied to the piezoelectric element (3) for manipulation, and a predetermined second voltage difference is applied to the piezoelectric element (3) for data transmission. The second voltage difference is selected to avoid operation of the actuator.

2. The method according to claim 1, characterized in that, By connecting the load (7) in parallel, the second voltage difference applied by the control device (1) is affected.

3. The method according to claim 2, characterized in that, In the case where the load (7) is connected in parallel, and in the case where the load (7) is not connected in parallel, determine the current required to apply the second voltage difference.

4. The method according to any one of claims 1-3, characterized in that, The first voltage difference and the second voltage difference have opposite signs.

5. The method according to any one of claims 1-3, characterized in that, The actuator (2) has a control logic device (9); information about the characteristics of the actuator (2) is stored in the control logic device (9); the information about the characteristics is transmitted to the control device (1) using the data; and the control device (1) uses the transmitted data to operate the actuator (2).

6. The method according to claim 5, characterized in that, The control logic device (9) stores the following information about the characteristics of the actuator (2): the information was determined by measuring the characteristics of the actuator (2) during the production of the actuator (2).

7. An actuator (2) having a piezoelectric element (3) for use according to the method of any one of claims 1-6, characterized in that, Components are provided to connect the load (7) in parallel with the piezoelectric element (3), or not in parallel, in order to transmit data.

8. A control device (1) for operating the actuator (2) according to claim 7, characterized in that, The device is provided with a component for manipulating the piezoelectric element (3) and other components that are identified as either connected in parallel with the piezoelectric element (3) or not connected in parallel with the load (7), and thus receive data sent by the actuator (2).

Images