Method and arrangement for monitoring status of control device

Abstract

The invention relates to a method for monitoring the state of a control device, in which a change in a supply voltage of the control device during switching is evaluated using a first monitoring module, in which a current reaction time is determined, the current reaction time is compared with a value of the beginning of the reaction time, such that a difference is determined, and the change in the supply voltage of the control device during switching is evaluated using a second monitoring module. The difference value carries information related to the state of the control equipment. The invention also relates to an arrangement for monitoring.

Description

Technical Field

[0001] The present invention relates to a method for monitoring the state of a control device and an arrangement for carrying out the method. Background Art

[0002] A control device is an electronic module that is put into use at a location where certain things must be controlled or regulated. In motor vehicles, control devices are used in different fields.

[0003] In modern control devices, such as in sensor control devices, especially in systems with a high SAE (Society of Automotive Engineers) ASIL (Automotive Safety Integrity Level) classification, i.e., systems with a level 2 or higher level, it becomes increasingly important to monitor the state, especially the technical state. Especially for L4 control devices used in vehicles, such as commercial vehicles, it is important to know at what point in time the control device must be repaired or replaced.

[0004] To achieve this goal, new solutions must be adopted to verify the technical state of the control device. Since each control device has a very high cost, simple solutions using timers or counters are not sufficient.

[0005] In L3+ systems, a monitoring unit is used to monitor all supply voltages or voltage rails. The monitoring unit can use an analog-to-digital converter (ADC) to measure the current voltage of the voltage rail and can compare it with the calculated minimum or maximum threshold of the voltage rail, usually within a window of + / - 3%. In addition, a comparator can be used to perform continuous monitoring against other thresholds. Usually, the maximum classification of the supplied facility, such as the maximum classification of a SoC (System on Chip), is adopted. The ADC can detect slow voltage fluctuations and can verify whether the voltage is within a pre-given range, which is called low-frequency (NF) monitoring. The comparator can detect fast voltage peaks and voltage drops, which is called high-frequency (HF) monitoring. Separate monitoring thresholds for overvoltage and undervoltage are given for these two methods.

[0006] The monitoring unit can also measure the on-time and off-time of the assigned voltage rail to verify whether the on-sequence and off-sequence are as defined. In this regard, refer to Figure 1 , in Figure 1 the basic pattern is shown.

[0007] Document DE 10 2019 213 654 A1 describes a method for verifying the functionality of a self - sufficient supply unit of a control device for at least one personal protection measure in a vehicle. In this method, the detection process of the voltage is decoupled, the detection time length is detected, and the functionality of the self - sufficient supply unit is detected based on the detected voltage and / or the detected time length.

[0008] A method for operating a controller for a starting device is known from document DE 10 2009 047 034 A1. The starting device has a starting motor for starting an internal combustion engine of a vehicle with an on - vehicle electrical network. Here, the starting motor is driven by the controller, more precisely, especially for the start - stop operating mode of the vehicle. In order to reduce the load on the on - vehicle electrical network, especially the voltage dip, during the starting process, the controller detects at least one parameter for determining the state of the on - vehicle electrical network, and the starting motor is driven at least based on this parameter. Summary of the Invention

[0009] In this context, a method according to the invention and an arrangement according to the invention are proposed. Embodiments result from the following description.

[0010] The proposed method is used to monitor the state of a control device. In this method, when a switch, especially when turning on the control device, a first monitoring module analyzes the change process of the supply voltage of the control device, where the current response time or response duration is determined and compared with the starting value of the response time, so that a difference is obtained, and this difference carries information related to the state of the control device.

[0011] In one embodiment for analyzing the start - up (hochfahren) of the control device, the start - up time (Anlaufzeit) or start - up duration (Anlaufdauer) is used as the response time. In another embodiment for analyzing the shutdown or turn - off of the control device, the decay time or decay duration is analyzed.

[0012] Therefore, a method is proposed which, in one configuration, is used to monitor the state of the energy supply and some PCB parameters (PCB: printed circuit board).

[0013] The proposed arrangement or monitoring arrangement is used to perform the described method and is implemented, for example, in hardware and / or software. The arrangement can be integrated in the control device of a motor vehicle or be configured as such.

[0014] Further advantages and configurations of the invention result from the description and the drawings.

[0015] It should be understood that, without departing from the framework of the present invention, the features described above and those to be explained below can be used not only in the given combinations respectively, but also in other combinations or alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 An embodiment of the proposed monitoring arrangement is shown in a block diagram.

[0017] Figure 2 The voltage change process is shown in a graph to illustrate the proposed method.

[0018] Figure 3 The voltage change process is shown in a graph to illustrate an embodiment of the proposed method.

[0020] Figure 4 An embodiment of the proposed monitoring arrangement is shown in a block diagram.

[0021] Figure 5 Another voltage change process is shown in a graph.

[0022] Figure 6 A vehicle with a control device is shown in a highly simplified schematic diagram. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention is schematically illustrated by means of the embodiments in the drawings and will be described in detail hereinafter with reference to the drawings.

[0024] Figure 1 A monitoring arrangement or a monitoring setup for monitoring is shown in a basic circuit diagram, which is globally identified by the reference numeral 10. The figure shows a regulator 12, a voltage divider 14 with resistors R1 16 and R2 18, and a processor 20 acting as a consumer, which is configured as a SoC in the present case. The figure also shows a monitoring module 22, in which a slow-working ADC (analog-to-digital converter) 24, a continuously operating comparator 26, and a logic unit 28 are provided.

[0025] Figure 2 The voltage change process is shown in graph 50, in which the abscissas 52 and 54 are plotted as time and the ordinate 56 is plotted as voltage. The figure shows an input signal change process 60 showing a turn-on pulse and an analyzed signal change process 62, which, as clarified by arrow 64, shifts towards change process 66.

[0026] The double arrow 70 indicates the typical time for the voltage to reach the set value after being switched on. This time is determined, stored separately for each device in the new state, measured each time the device is started, and the measured time is compared with the initial value determined in the new state. The double arrow 72 illustrates the turn-on delay of the voltage regulator, i.e., the time elapsed from when the regulator receives the turn-on signal until it starts regulating. The double arrow 74 illustrates the time required for the regulator until the voltage stabilizes, which is also referred to as the Softstart Time. The reference numeral 76 in the figure illustrates the variation process of the regulator output voltage.

[0027] In modern control devices, on-vehicle monitoring units are used to verify the correct turn-on and turn-off sequences, which can be inferred from Figure 2 Therefore, the minimum and maximum durations or operating times of each voltage rail are calculated relative to the enabling signal or activation signal for the first voltage rail, and this is illustrated by the dashed line 80 in Figure 2 Then, each time the main SoC is started or put into operation, it is measured and verified whether the sequence is adhered to. The tolerances are caused by input parameters:

[0028] Soft start of the regulator (regulator + external R-C (Resistor-Capacitor));

[0029] EN (Enable) delay in the regulator;

[0030] EN delay in the turn-on sequence.

[0031] At this point, the first aspect of the proposed method is considered in detail:

[0032] In the new control device, the signal variation process 62 shown in Figure 2 shows the ramp-up of the voltage. The time measured during the first start-up (Hochfahren), for example, the time measured in the regulation path at the end of the line test, should be stored in a non-volatile memory (NVM: non volatile memory). In practice, this time is measured each time the SoC is started. Due to the aging of components, the signal variation process 62 shifts to the left or right, for example, towards the variation process 66 in Figure 2

[0033] The time difference can be calculated by comparing the start-up time or turn-on time with the starting value. With this degradation, the end of operation of the regulator and the external circuit can be predicted. After the shift reaches a certain ratio, the end of operation of the control device can be estimated better.​

[0034] It should be noted that the regulator and its external circuit are particularly important during the start-up sequence.

[0035] The shutdown process will be explored later.

[0036] Figure 3 The course of voltage change is shown in Chart 100, in which the abscissas 102 and 104 are plotted as time and the ordinate 106 is plotted as voltage. This chart shows the course of the input signal change 110 including the turn-off pulse and the analyzed signal change 112, as clarified by arrow 114. The analyzed signal change 112 shifts towards the change 116.

[0037] The double arrow 120 clarifies the discharge time from the shutdown signal until the output voltage is below the defined threshold, for example 0.2 V. The double arrow 120 shows the variance of the time 120 given by the component tolerances.

[0038] The correct shutdown sequence is very important for modern SoCs. This is also verified by this external monitoring. The decay time (Abklingzeit) or shutdown time of each voltage rail is calculated using all tolerances, that is Figure 3 the dotted line in. The input parameters are:

[0039] The capacitance of the buffer capacitor;

[0040] The discharge current;

[0041] The voltage on each voltage rail;

[0042] The discharge current of each voltage rail;

[0043] The deactivation delay / sequence in the energy sequence.

[0044] Each voltage rail usually discharges actively during shutdown to ensure that each voltage rail discharges quickly and surely. The activation signal of the regulator usually reverses the discharge signal of the assigned voltage rail.

[0045] Another aspect of the proposed method will be explored later.

[0046] In the new control device, the signal change 112 shown in Figure 3 shows the voltage down-ramp. The time measured during the first shutdown, for example at the end of the line test in the regulation path, should be stored in the non-volatile memory. In practice, this time is measured at each SoC shutdown. Due to component aging, the signal change 112 shifts to the left, for example towards the change 116 in Figure 3

[0047] The time difference can be calculated by comparing the decay time with the starting value. With this degradation, the end-of-life of the decoupling capacitor and the external circuit can be estimated. After a certain ratio has been reached over time, the end-of-operation of the control device can be estimated well.

[0048] During the turn-off sequence, the capacitor and the discharge circuit are particularly important.

[0049] Now, let's explore the dynamic verification of the regulator and decoupling:

[0050] The tests explained above are used to verify the static behavior of the external circuit. This already gives a good indication, however, this is not sufficient for the core voltage rails with high power. Since the peak current in the range of 100 to 200 A is very high and the requirements for power integrity on these voltage rails are very high, additional monitoring is necessary. The goal of this monitoring is to verify the power integrity of the core voltage rails. The impact on integrity is given by the following parameters:

[0051] The capacitance of the decoupling capacitor;

[0052] The internal resistance of the capacitor;

[0053] The PCB core material (dielectric constant, hereinafter referred to as epsilon 0).

[0054] Another aspect of the proposed method will also be explored:

[0055] In order to analyze the voltage rails considering degradation and aging, additional monitoring must be carried out for all high-power voltage rails, such as for the core voltage rail, the DDR voltage rail (DDR corresponds to the memory RAM), and generally high-power voltage rails.

[0056] Figure 4 Another monitoring arrangement is shown in the circuit diagram, which is generally identified by the reference numeral 200. The figure shows a regulator 202, a voltage divider 204 with resistors R1 206 and R2 208, a processor 210 as a consumer, which is configured as a SoC in the current case. The figure also shows a first monitoring module 220, in which a slow-working ADC 224, a fast-working comparator 226, and a logic unit 228 are provided. In addition, a correspondingly constructed second monitoring module 250 is provided.

[0057] The existing monitoring carried out by the first monitoring module 220 cannot be used for the task because the first monitoring module 220 must ensure that the supply voltage is always within the maximum classification or maximum evaluation.

[0058] The two monitoring modules 220 and 250 are identical, i.e., they have the same hardware, but different threshold configurations. Each monitoring has the option: to measure the average voltage using an ADC, and if the given threshold is reached, then trigger a reaction. The measurements made using the ADC are always time-discrete and not continuous, which in turn means that small peaks may be lost. This is shown in Figure 5 as follows.

[0059] Figure 5 Different processes are shown in the graph 300, i.e., the maximum range 310. In the graph 300, the abscissas 302 and 304 are plotted as time, and the ordinate 306 is plotted as voltage. The reference numeral 312 indicates that after a certain aging of the device, the initial threshold 314 is exceeded in order to determine by how much the threshold needs to be increased so that it will not be exceeded even under high load. The reference numeral 312 represents the initial threshold for voltage monitoring, deliberately below the maximum allowable threshold, which will not be exceeded in a new device. The reference numeral 316 shows an example of a discrete voltage process. The reference numeral 318 is similar to 314, just below it. The reference numeral 320 is similar to 312, just below it. The reference numeral 324 marks the allowable voltage. The process 326 represents a fault signal.

[0060] The point 330 is an ADC sampling point. The threshold for the ADC in the second monitoring module is the same as the threshold configured in the second monitoring module, i.e., the dashed lines 340 and 342.

[0061] The difference lies in the high-frequency monitoring using a comparator. The threshold is reduced or reduced to the 3% line at around the 3% line. In Figure 5 310 and 324 are the thresholds used in the first monitoring module, and 314 and 318 are the thresholds used in the second monitoring module.

[0062] In a new control device, since all components are in good condition, 314 and 318 will not be reached. Due to the aging of the decoupling capacitors, the voltage drops or the voltage peaks increase and reach the thresholds (indicated by the reference numerals 314 and 318). This is not a problem for the overall operation of the SoC.

[0063] The change of the threshold should be carried out step by step until the threshold is not reached during a long running time, for example, one hour. After several consecutive running hours, due to the aging of components, such as the aging of capacitors, the threshold will also be reached, and the threshold must be adjusted, for example, to the thresholds (indicated by the reference numerals 312 and 320). It is important that any change must be within the range of the maximum value, i.e., within the range of the thresholds (indicated by the reference numerals 310 and 324).

[0064] Using information related to a change between a threshold (indicated by reference numerals 314 and 318) and a threshold (indicated by reference numerals 312 and 320), i.e., the running time, such as a voltage change, the remaining running time until the maximum classification is reached can be calculated.

[0065] Figure 6 In a highly simplified illustration, a vehicle 400 with a control device 402 is shown, and the state of the vehicle is monitored. For this purpose, a first monitoring module 404 and a second monitoring module 406 are used. These two monitoring modules 404, 406 are typically arranged in a monitoring arrangement or in the manner of a monitoring arrangement.

Claims

1. A method for monitoring the state of a control device (402), in which a first monitoring module (22, 20, 404) is used to analyze the change process of the supply voltage of the control device (402) when the control device (402) is switched, wherein, Determine the current reaction time, compare the current reaction time with the starting value of the reaction time such that a difference is obtained, the difference carrying information regarding the state of the control device (402).

2. The method according to claim 1, wherein the method is performed when starting the control device (402), where Compare the current actuation time, which is the current reaction time, with the starting actuation time, which is the starting reaction time.

3. The method according to claim 1, wherein the method is executed when the control device (402) is shut down, where Compare the current decay time, which is the current reaction time, with the starting decay time, which is the starting reaction time.

4. The method according to any one of claims 1 to 3, wherein a second monitoring module (22, 250, 406) is used in the method.

5. The method according to any one of claims 1 to 4, wherein a value of the starting reaction time is used in the method, the value being stored in a non-volatile memory.

6. An arrangement for monitoring a status, the arrangement being configured to perform the method according to any one of claims 1 to 5, wherein, The arrangement (10) has a first monitoring module (404).

7. The arrangement according to claim 6, the arrangement having a second monitoring module (406).

8. The arrangement according to claim 6 or 7, wherein, in the arrangement, the first monitoring module (404) has an analog-to-digital converter (24, 224) for verifying slow voltage changes and a comparator (26, 226) for verifying fast voltage changes.

9. The arrangement according to any one of claims 6 to 8, wherein, in the arrangement, the second monitoring module (406) has an analog-to-digital converter (24, 224) for verifying slow voltage changes and a comparator (26, 226) for verifying fast voltage changes.

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