Control unit

Abstract

Control device, in particular an electronic transmission control device, for controlling the operation of a system to be controlled, in particular a transmission of a motor vehicle, wherein the control device has a modular functional architecture with a plurality of control modules (1, 2, 3, 4) connected in series and a signal conditioning module (5), wherein first control modules (1, 2, 3) generate output variables from input variables that the signal conditioning module (5) and / or another first control module (1, 2) connected upstream of the respective first control module (2, 3) provide as output variables, which are input variables of another first control module (2, 3) connected downstream of the respective first control module (1, 2) or of a second control module (4) connected downstream of the respective first control module (3), which outputs a variable for controlling the system to be controlled.characterized by a monitoring device (12) covering all control modules (1, 2, 3, 4) connected in series, wherein the monitoring device (12) monitors the output of the second control module (4) for the purpose of functional testing of all control modules (1, 2, 3, 4) on the basis of plausible measurement signals of the system to be controlled without accessing the outputs of the first control modules (1, 2, 3).

Description

[0001] The invention relates to an electronic control device, in particular an electronic transmission control device, according to the preamble of claim 1.

[0002] Electronic control systems are subject to increasingly stringent demands with regard to safeguarding against or preventing safety-critical situations. To this end, an electronic control system performs a variety of monitoring functions for the processes controlled by the electronic control system, as well as for monitoring the internal execution of program commands.

[0003] Fig. 1 illustrates the structure of an electronic transmission control device known from the prior art, wherein the electronic transmission control device of the Fig. 1 comprises a modular functional architecture with a plurality of control modules 1, 2, 3, and 4 connected in series. Control module 1 is an operating concept control module, control module 2 is a driving strategy control module, control module 3 is a transmission function control module, and control module 4 is an actuator control module.

[0004] Based on output variables of a signal conditioning module 5, the operating concept control module 1 generates a target transmission position signal with a target transmission position as an input variable for the operating concept control module 2, wherein the target transmission position is one of the transmission positions P (parking), R (reverse), N (neutral), or D (forward). Based on the target transmission position signal and the output variables of the signal conditioning module 5, the driving strategy control module 2 generates a target gear signal with at least one target gear as an input variable for the transmission function control module 3.

[0005] Based on the target gear signal and output variables of the signal processing module 5, the transmission function control module 3 outputs a target control signal - for example, target currents - as an input variable for the actuator control module 4, wherein the actuator control module 4 outputs an actual control signal based on the target control signal as an output variable for controlling the transmission to be controlled.

[0006] The signal processing module 5 processes signals 6, whereby the signals 6 can be, for example, measurement signals of the transmission to be controlled as well as signals from the engine or other control units in the vehicle network present in the vehicle electrical system, for example an engine speed.

[0007] The control modules 1, 2 and 3 are therefore first control modules which generate output variables from input variables which the signal processing module 5 and / or another first control module 1, 2 connected upstream of the respective control modules 1, 2, 3 provides as output variables, which are input variables of another first control module 2, 3 connected downstream of the respective first control module 1, 2 or of a second control module 4 connected downstream of the respective first control module 3, which second control module outputs an output variable for controlling the system to be controlled.

[0008] At the Fig. In the electronic transmission control device shown in Figure 1, which is known from the prior art, monitoring of the same is realized by assigning an independent monitoring module 7, 8, 9, 10, and 11 to each of the control modules 1, 2, 3, and 4 as well as to the signal processing module 5 in order to monitor the control modules 1 to 4 and the signal processing module 5. A large number of input variables are required for the individual monitoring modules 7 to 11, which must be protected.

[0009] This means that in the prior art electronic transmission control system, a multitude of complex signal calculations must be performed to provide secure signals for the individual monitoring modules 7 to 11. Therefore, the monitoring function in a prior art electronic transmission control system requires a significant amount of memory and computing power. This is complex and expensive.

[0010] Another such electronic control device for controlling a transmission of a motor vehicle is known, for example, from document DE 44 20 930 A1.

[0011] Based on this, the present invention addresses the problem of creating a novel electronic control device that allows safety-relevant monitoring with less memory space and less computing power. This problem is solved by an electronic control device according to claim 1. The electronic control device according to the invention comprises a monitoring device covering all control modules connected in series. The monitoring device monitors the output variable of the second control module based on plausibility-checked measurement signals from the system to be controlled, without accessing the output variables of the first control modules, to check the functionality of all control modules.

[0012] According to the invention, monitoring is not carried out on individual control modules, as is usual in the prior art, but rather across all control modules. For this purpose, the output signal of the control module that outputs an output variable for controlling the system to be controlled is fed to a monitoring device. The monitoring device monitors this output variable based on plausibility-checked measurement signals from the system to be controlled to check the functionality of all control modules. This monitoring device does not have access to the output variables of the control modules, whose output variables are further processed in other control modules and therefore not output to control the system to be controlled.

[0013] By using such a monitoring device covering all control modules, it is possible to reduce the storage space and computing power required to implement the monitoring function.

[0014] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 is a block diagram of an electronic control device known from the prior art; and Fig. 2 a block diagram of an electronic control device according to the invention.

[0015] The present invention will be described below with reference to Fig. 2 is described in detail using the example of an electronic transmission control device.

[0016] The Fig. The electronic transmission control device according to the invention shown in Figure 2 again has a plurality of control modules 1, 2, 3 and 4 connected in series, wherein the control module 1 is the operating concept control module, the control module 2 is the driving strategy control module, the control module 3 is the transmission function control module and the control module 4 is the actuator control module. Furthermore, the electronic transmission control device according to the invention of the Fig. 2 a signal processing module 5, which processes signals 6.

[0017] Based on output variables of the signal conditioning module 5, the operating concept control module 1 outputs a target transmission position signal as an input variable for the operating concept control module 2, which represents one of the transmission positions P (parking) or R (reverse) or N (neutral) or D (forward) as the target transmission position.

[0018] Based on the target transmission position signal output by the operating concept control module 1 and output variables of the signal processing module 5, the driving strategy control module 2 outputs a target gear signal as an input variable for the transmission function control module 3.

[0019] The transmission control function module 3 generates a target control signal, in particular target currents, as an input variable for the actuator control module 4 on the basis of the target gear signal and output variables of the signal processing module 5, wherein the actuator control module 4 outputs an actual control signal as an output variable for controlling the transmission to be controlled on the basis of the target control signal output by the transmission function control module 3.

[0020] The control modules 1, 2 and 3 are therefore control modules which generate output variables from input variables which the signal conditioning module 5 and / or a control module 1 or 2 upstream of the respective control module 2 or 3 provides as output variables, which are input variables of a control module 2, 3 or 4 downstream of the respective control module 1, 2 or 3.

[0021] The control module 4 is a control module which, based on the output variables of a control module 3 upstream of the same, outputs an output variable which serves to control the system to be controlled, in this case the transmission to be controlled.

[0022] The transmission control device according to the invention of Fig. 2 comprises a monitoring device 12 which covers all of the control modules 1, 2, 3 and 4 connected in series, wherein the monitoring device 12 monitors the output variable of the actuator control module 4, which serves to control the transmission to be controlled, on the basis of plausibility-checked measurement signals of the transmission to be controlled, for monitoring all of the function modules 1 to 4 connected in series, without access to the output variables of the other control modules, i.e. without access to the output variables of the operating concept control module 1, the driving strategy control module 2 and the transmission function control module 3.

[0023] If necessary, the monitoring device 12 also uses, in addition to the plausibility-checked measurement signals of the transmission to be controlled, a plausibility-checked engine speed of an engine coupled to the transmission to be controlled or signals from other control units in the vehicle network. A signal selection module 13 selects from the totality of available signals 6 those signals that the monitoring device 12 requires for the joint functional check of all control modules 1 to 4, with the signal selection module 13 providing these signals to the monitoring device 12.

[0024] It is therefore within the scope of the present invention to control the function of all control modules 1 to 4 connected in series in Fig. 2 with the aid of the monitoring device 12 covering all control modules 1 to 4, wherein the monitoring device 12 monitors the output variable of the control module 4, which serves to control the system or transmission to be controlled, on the basis of plausibility-checked measurement signals of the controlling transmission, and specifically without access to the output variables of the control modules 1 to 3 connected upstream of the control module 4, the output variables of which merely represent intermediate variables and are not output to control the system to be controlled.

[0025] The dashed arrows of the Fig.2 illustrate that the output variables of the control modules 1, 2 and 3 of the control device according to the invention, which are not output for controlling the system or transmission to be controlled and therefore only represent intermediate variables, can also be fed to the monitoring device 12 in order to then monitor them in the monitoring device 12 on the basis of plausibility-checked measurement signals of the system or transmission to be controlled and, if appropriate, on the basis of the plausibility-checked engine speed of the engine coupled to the transmission or other signals from control devices in the vehicle network, whereby, however, the output variables of the control modules 1 to 3 are not used to monitor the output variable of the control module 4.

[0026] In the case of the preferred embodiment of an electronic transmission control device, the target transmission position signal output by the operating concept control module 1 as an intermediate variable and / or the target gear signal output by the driving strategy control module 2 as an intermediate variable and / or the target control signal output by the transmission function control module 3 as an intermediate variable is only monitored and checked for plausibility in the monitoring device 12 if the respective signal is used, for example, in a driver assistance system to automatically trigger a function there.

[0027] If, however, output variables output as intermediate variables by the control modules 1 to 3 of the control device according to the invention only serve to generate the output variable output by the control module 4 for controlling the system or transmission to be controlled, these intermediate variables are not monitored separately in the monitoring device 12.

[0028] In accordance with the present invention, the memory and computing power requirements of monitoring functions of an electronic control device featuring a modular functional architecture with a plurality of cascaded control modules can be reduced by not monitoring individual control modules, but rather by using a monitoring system that encompasses or covers all control modules. For this purpose, not all output variables of all control modules are secured, but only the output variable of the control module that outputs an output variable for controlling the system to be controlled.This output variable, which is used to control the system to be controlled, is compared with plausibility-checked measurement signals of the system to be controlled and, if applicable, with plausibility-checked signals of a system coupled to the system to be controlled in order to implement the monitoring function. Reference symbol 1 control module 2 Control module 3 Control module 4 Control module 5 Signal conditioning module 6 signals 7 Monitoring module 8 Monitoring module 9 Monitoring module 10 Monitoring module 11 Monitoring module 12 Monitoring device 13 Signal selection module

Claims

[1] Control device, in particular an electronic transmission control device, for controlling the operation of a system to be controlled, in particular a transmission of a motor vehicle, wherein the control device has a modular functional architecture with a plurality of control modules (1, 2, 3, 4) connected in series and a signal processing module (5), wherein first control modules (1, 2, 3) generate output variables from input variables provided as output variables by the signal processing module (5) and / or another first control module (1, 2) connected upstream of the respective first control module (2, 3), which output variables are input variables of another first control module (2, 3) connected downstream of the respective first control module (1, 2) or of a second control module (4) connected downstream of the respective first control module (3), which outputs an output variable for controlling the system to be controlled, characterized bya monitoring device (12) covering all control modules (1, 2, 3, 4) connected in series, wherein the monitoring device (12) monitors the output variable of the second control module (4) on the basis of plausibility-checked measurement signals of the system to be controlled without access to the output variables of the first control modules (1, 2, 3) in order to check the functionality of all control modules (1, 2, 3, 4). [2] Control device according to claim 1, characterized by that the monitoring device (12) continues to monitor output variables of the first control modules (1, 2, 3) on the basis of plausibility-checked measurement signals of the system to be controlled, but without using the output variables of the first control modules (1, 2, 3) to monitor the output variables of other first control modules (1, 2, 3) and / or the output variable of the second control module (4). [3] Control device according to claim 1 or 2, characterized bythat the control device is designed as a transmission control device and comprises at least three first control modules, namely an operating concept control module (1), a driving strategy control module (2), and a transmission function control module (3), as well as a second control module, namely an actuator control module (4), wherein the operating concept control module (1) outputs a target transmission position signal as an input variable for the driving strategy control module (2) on the basis of output variables of the signal processing module (5), wherein the driving strategy control module (2) outputs a target gear signal as an input variable for the transmission function control module (3) on the basis of the target transmission position signal and output variables of the signal processing module (5),wherein the transmission function control module (3) outputs a target control signal as an input variable for the actuator control module (4) based on the target gear signal and output variables of the signal processing module (5), wherein the actuator control module (4) outputs an actual control signal based on the target control signal as an output variable for controlling the transmission to be controlled, and wherein the monitoring device (12) monitors the actual control signal exclusively on the basis of plausibility-checked measurement signals of the transmission to be controlled and, if applicable, on the basis of a plausibility-checked engine speed of an engine coupled to the transmission or signals from other control units in the vehicle network, without using the target transmission position signal and the target gear signal and the target control signal. [4] Control device according to claim 3, characterized bythat the monitoring device (12) further monitors the target transmission position signal and / or the target gear signal and / or the target control signal on the basis of plausibility-checked measurement signals of the transmission to be controlled and, if appropriate, on the basis of a plausibility-checked engine speed of an engine coupled to the transmission or signals from other control units in the vehicle network, specifically when the target transmission position signal and / or the target gear signal and / or the target control signal automatically triggers a function.

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