KR100806460B1 - Method for controlling at least one external output stage by means of a data bus and a device for carrying out said method - Google Patents

Abstract

The present invention relates to a method for controlling at least one external output stage 3 via one data bus using a control device 1. In the method one acknowledgment signal is provided to the data bus after reception of the signal provided by the control device 1, and the confirmation signal is received by the control device 1 so that the control device 1 and the output terminal 3 are provided. It is used for synchronization between the servers.

Also described is an apparatus for the execution of the method according to the invention and an output stage 3 controlled according to the method.

Control Unit, Data Bus, External Output, Synchronization, CAN Bus, Electronic Unit, Control Line, Amplification Unit

Description

METHOD FOR CONTROLLING AT LEAST ONE EXTERNAL OUTPUT STAGE BY MEANS OF A DATA BUS AND A DEVICE FOR CARRYING OUT SAID METHOD}

1 is a block diagram of a preferred embodiment of the device according to the invention.

2 is a block diagram of a preferred embodiment of an output stage according to the present invention.

3 is a flow chart of the progress of communication between a control device and an output stage according to a preferred embodiment of the method according to the invention.

4 is a diagram relating to the modification of the injection timing which can be realized according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: control device

2: CAN bus

3: output

4: data line

5: valve

6: control line

8: electronic unit

The present invention relates to a method for controlling at least one external output stage via a data bus using a control device and an apparatus for implementing the method. The invention also relates to an output stage controlled according to the method.

The output stages used in motor vehicles are connected with different parts such as ignition coils, valves and injectors for injection and ignition. At this time, the output terminals for the parts to be controlled each include one control line as an input unit. The control device transmits an impulse via the data bus, in other words through the corresponding control line, whereby the ignition or injection is initiated. The pulse length corresponds, for example, to the volume to be injected. Synchronization over time is achieved by the location of the impulses. If a failure occurs, the failure must be identified by appropriate measures.

For example, arithmetic logic units of control devices for fuel injection and / or engine ignition of engines are known from German patent 43 37 132, in particular comprising one processor and one control logic. In the case of the arithmetic logic unit, a controller which serves as an interface is connected between the processor and the control logic. The controller is responsible for the designated task of the processor to reduce the load on the processor. It is provided that information is transferred between the processor and the control logic. For this information, the controller generates additional information, to which the control logic reacts and / or from the processor to the control logic, data which is not changed by the controller. At the same time, however, the controller preferably generates signals which are transmitted to the control logic via an internal data bus and / or which information is changed while passing through the controller between the processor and the control logic.

When transmitting data from the control device to the output, the problem arises that there is always a delay between the transmission at the transmitter, the control device and the reception of the complete message at the receiver and output. Since the output stage does not have any speed input, in other words no information is available considering the position of the crankshaft, this causes problems in the control of the injection and ignition system.

It is an object of the present invention to provide a method and apparatus in which part control is possible depending on the position of the crankshaft.

The object associated with the method is solved by a method having the features of claim 1.

The object associated with the device is solved by a device having the features of claim 3.

The output stage according to the invention is presented in claim 4.

Preferred embodiments of the invention are subject of the dependent claims.

The method according to the invention is used to control at least one external output stage while using one control device via one data bus. According to the invention, after receiving a signal from the control device, a confirmation signal is provided to the data bus, for example via an output stage. The signal is received by the control device and used to synchronize between the control device and the output.

In this manner the control device has information which makes it possible to measure the delay between sending and receiving a message.

Preferably serving as a data bus is a data bus using the CAN data transfer protocol. In the following, the CAN bus is named. Of course, another vehicle bus may be used, for example a TTP / C bus.

In the method according to the invention, the characteristic of the CAN which transmits an acknowledgment signal when the reception of the message via the bus is completed is used. This causes an interrupt not only at the transmitter but also at the receiver. The interrupt serves to synchronize the transmitter and the receiver.

If, for example, two output stages are controlled by one control device, data for the second output stage is transmitted when the first output stage should start with its own sequence. In detail, the following procedure can be considered. First, the control device transmits data to the first output terminal. When the reception of the data by the first output stage is completed, that is to say that the first output stage should be started in its own sequence, an acknowledgment signal is provided to the bus causing an interrupt in the output terminal and the receiver as well as the control device and the transmitter. The interrupt serves to synchronize. The data is then sent from the control device to the second output stage. Therefore, the above is made at the time when the first output stage should start with its sequence.

The control device with information about the crankshaft position uses the interrupt to measure the delay according to the setpoint and to compensate for subsequent injections if necessary via a corresponding algorithm.

In the method according to the invention, some cost is incurred because some cable connection is required between the control device and the output end. In addition, of course, a slight failure probability is caused. The CAN bus uses a finely tuned fault identification method and a fault correction method, which reduces the sensitivity to faults. Although the message is lost, the possibility of implementing a counter in the messages exchanged to ensure cylinder allocation is provided. The messages may also contain information on the level of current or voltage, in addition to the on / off pulse.

The apparatus according to the invention for carrying out the method described above comprises one control device and at least one output stage. The device is characterized in that at least one output is connected to the control device via one CAN bus.

The output stage for carrying out the method comprises one control unit connected to one CAN bus and one controller comprising one first demultiplexor and one for time dependent control comprising a second demultiplexer. An electronic unit and one amplifier unit. The control unit is connected to the electronic unit via a first control line, and the electronic unit is connected to the amplification unit or power output state through a second control line. The power output stage supplies a signal for the actuator to be actuated, for example a valve. The control unit is connected to the control device via a CAN bus.

Preferably the control unit and the electronic unit are integrated in one electronic module.

Therefore, the controller that generates the signal to directly control the power output stage can be adjusted using CAN. Since the functionality is not too complex in the alternative, use ASICs (application-specific integrated circuits) instead of microcontrollers. CAN structural member (structural member) is a VHDL block; available as (in English V ery H igh Speed IC Hardware D escription L anguage High Speed IC Hardware Description Language), and the rest of the state machine (state machine), for example, execute control according to the time An executive state machine is easily implemented. If the evaluation of the CAN message and the control of the amplification unit is done as an ASIC, it is usually possible to transmit the data of the injection in a cylinder synchronized manner, and to use interrupts at the end of the transmission, to rewrite the message and to generate the signal. The machine can be started immediately.

The invention is explained in more detail according to the accompanying drawings.

Figure 1 shows a preferred embodiment of the device according to the invention. The device controls the injection in the engine. The device shown is a control device 1, a CAN bus 2, an output stage 3, three data lines 4 and a valve 5. The control device 1 is connected to the output stage 3 via the CNA bus 2. The control device 1 transmits data to the output terminal 3 to initiate the injection process via the CAN bus 2. The data are evaluated in the output stage 3 and continue to be transmitted to the valve 5 via the data line 4. The valve then starts the injection process.

In figure 2 a preferred embodiment of the output stage 3 according to the invention is shown in detail.

The output stage comprises a control unit 6, five first control lines 7, an electronic unit 8, nine second control lines 9 and a power output stage 10.

Via the CAN bus, the control unit 6 obtains a message about the injection to be performed. The control unit 6 may for example be formed as a microcontroller or a CAN controller. The control unit also includes a demultiplexer, whereby the incoming signal is transmitted to the five first control lines 7. In the electronic unit 8 for control over time, the signals are continuously processed and transmitted by an additional demultiplexer to the power output stage 10 via nine second control lines 9. The power output stage generates output signals for controlling the valve 5 via the data lines 4.

The control unit 6 and the electronic unit 8 may be integrated in one electronic module, for example in an ASIC. This means that the CAN controller generates signals for the power output directly. Implementation within one ASIC proves to be desirable. CAN structural members are available as VHDL blocks. The state machine needed to generate the control signal is easily implemented in the ASIC. This significantly reduces the cost and allows for a simple configuration. The data of injection can be sent in a cylinder synchronized manner, an interrupt can be used at the end of the transmission to rewrite the message and immediately start up the state machine for signal generation.

Figure 3 illustrates the communication via a CAN bus between one control device and two output stages.

Using step 20, the control device sends an impulse to one first output. The output receives the impulse sent in step 21. After reception is complete, the characteristic of the CAN to transmit an acknowledgment signal (acknowledgement) (step 22) is used. This allows for equal bus conditions on the CAN bus. The confirmation signal causes an interrupt in step 23 for the first output stage and in step 24 for the control device. The interrupt serves to synchronize between the control device and the first output terminal. The interrupt begins in step 25 with the first output end of its own sequence for initiating injection and in step 26 the control device sends data for the second output end.

Data transmission for injection is divided into two stages. In the first stage, the general output stage configuration is transmitted. The output stage can thus always have a defined characteristic. The output stage is always dependent on a preset current characteristic (common rail solenoid valve), or determines a constant voltage level, regardless of how much the pulse length should be (common rail piezo control device). In the second step, actual injection data is transmitted. The transmission is made just before the injection, and includes the injection period. Because a complete transmission based on a unified bus state causes an interrupt in both devices, the transmitter and the receiver, an interrupt is used at the output to initiate the sequence while the deviation of the desired angle within the control device is measured. Can be. Subsequent injections are then initiated before or after the corresponding deviation. Similar methods and precision controls for determining the deviation of the mean can be considered.

Two messages are required for use for ignition control. The first message serves to induce the current supply phase of the ignition coil and includes the set current (corresponding to the cam angle so far) depending on the situation. The second message serves to induce ignition, and does not necessarily contain useful data. The message can only be thought of as a trigger. However, for safety reasons, at least the cylinder number must be transmitted in order to allow control of the message for allocation in case of failure.

Since the control device uses information relating to the crankshaft position, an interrupt is used to measure the delay to the set point in some cases and to compensate for subsequent injection by the corresponding algorithm if necessary. This point is shown in FIG.

At the time point 30, data transmission from the control device to the output terminal is started. The transmission period is specified by a bar. At the time point 31, the transmission ends. The time point 31 is named as φist (actual time). As a result, the injection 32 is started. However, the injection should already be made about the time point 33? Soll (set time). This information is held by the control device because the control device uses information relating to the position of the crankshaft. The time difference between the set time and the actual time is given by the following formula.

delta t = t (φsoll)-t (φist).

The exact time point for the transmission of the next injection message is calculated as follows:

φsoll-t _DUE -delta (z-1).

T _tUE is the time required to transmit the message. delta (z-1) is the difference according to the time between the set time of the preceding injection and the actual time.

According to the present invention, synchronization is achieved between the control device and the output stage, so that delay-free message transmission and reception are performed so that trouble-free ignition and injection are performed.

Claims (5)

In a method for controlling at least one external output stage 3 via one data bus using a control device 1, The external output terminal 3 provides one confirmation signal to the data bus after reception of the signal provided by the control device 1, which confirmation signal is received by the control device 1 so that the control device 1 and the output terminal are received. (3) An external output stage control method, characterized in that it is used for synchronization between. The method of controlling an external output stage according to claim 1, wherein a CAN bus (2) is used as a data bus. In a device for carrying out the method according to claim 1 or 2 with a control device 1 and at least one output stage 3, the at least one output stage 3 is connected to one CAN bus 2. A device characterized in that it is connected with the control device (3) via. In the output stage 3 controlled by the method according to claim 1 or 2, A control unit 6 with one first demultiplexer connected to one CAN bus 2, an electronic unit 8 for controlling over time with a second demultiplexer, and an amplification unit 10 The control unit 6 is connected to the electronic unit 8 via a first control line 7, the electronic unit being connected to the amplification unit 10 via a second control line 9. An output stage, characterized in that connected. 5. An output stage according to claim 4, characterized in that the control unit (6) and the electronic unit (8) are integrally formed in one electronic module for control over time.

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