DE4409563A1 - Electric vehicle electrical components initialisation and self-test - Google Patents

Abstract

The startup and self-test method for automobile electrical equipment in electric vehicles is performed in two stages. The pre-start test stage 2 (Stufe-2) is started by a second sensor signal (Signal-2) which indicates that the first test stage initiated by sensor signal (Signal-1). The first test stage uses less energy than the second, and is initiated by a sensor such as seat pressure or door opening. The second test stage uses a greater amount of energy, and is initiated by a sensor indicating a high probability of starting, such as ignition key operation. It is only performed on successful completion of the first stage.

Description

The invention relates to a method for prior checking and Preparation of electrical components in electric vehicles according to the preamble of claim 1.

Electronically controlled electric vehicles have a very complex electrical and electronic networking of sensors, Connectors, cables, data acquisition and processing plants on. Therefore, before every start of the electric vehicle an automatic self-diagnosis of all electrical, elec tronic and electromechanical components. These Prior checking is lengthy and can take some time to take. In the event that the prior check is only carried out by the The driver would have to start operating the ignition lock therefore wait a relatively long time for the start approval.

From patent application P 43 22 767.8-32 a Ver drive to start an electric vehicle known by a vehicle door or seat contact sensor test for gas sensors is started. However, it can happen that by checking the contacts several times the check started several times and thereby the vehicle battery is unnecessarily burdened.

In addition, from DE-OS 41 00 133 a method for elec preheating a catalyst system for a motor vehicle Stuff known, in which the heating time in several heating periods is divided, the partial heating periods by sensor signals, who know the upcoming commissioning of the motor vehicle draw, start.  

The object of the invention is to provide a method for Prior checking of electrical components in electric vehicles to improve so that the consumption of electrical energy is reduced.

The object is achieved by the characterizing Features of claim 1 solved.

The division of the necessary prior checks into two, from depending on the respective energy requirement has the advantage that the first stage, which has a lower energy requirement points, by a relatively early characteristic sensor signal can be started. The second, more energy-intensive stage is only started when the electrical system is started up vehicle is very likely to come. So can the time until the start approval was given and yet unnecessary energy consumption can be prevented.

Further advantages and configurations result from the subclaims Chen and the description. The invention is as follows based on a drawing showing a flowchart of a fiction shows the method described in more detail.

After the start of the method in block 1 , the variables t, I₁, I₂, Flag_1 and Flag_2 are reset in block 2 , that is to say assigned the value zero. The method can be started immediately after the electric vehicle is switched off or only after a predetermined period of time has elapsed. It is then checked in block 3 whether the battery voltage U _bat exceeds a lower limit value U _min . If the battery voltage U _bat falls below this limit value, a branch is made to block 4 , where the method is ended. This is to prevent a weak battery from being further weakened by starting the prior check several times. In this case, the preliminary check is only carried out after the ignition lock has been actuated. If, on the other hand, the battery has a sufficient state of charge, the process jumps from block 3 to block 5 , where it is checked whether a first sensor signal Signal_1 has been received. The first sensor signal, hereinafter referred to as Signal_1, is generated by one or by a combination of several sensors that indicate the probability of the electric vehicle being put into operation. Suitable sensors are, for example, a seat contact, a door light contact, a door lock contact, a door handle sensor or a proximity sensor.

If no signal_1 was received in block 5 , the method is continued in block 13 . If, on the other hand, a Signal_1 has been received, a check is made in Block 6 to determine how often Signal_1 has been received so far. If the number I _{1 exceeds} a predetermined maximum number I _{max 1} , the _{process jumps} to block 13 without starting the stage_1 of the prior check. If the maximum number I _max1 has not yet been reached, it is checked in block 7 whether a predetermined time period t _{max has} elapsed since the start of the method, for example after the vehicle has been switched off. If this is the case, the process jumps directly to block 13 . The first stage_1 of the prior check is started in block 8 only if the time period t _max has not yet been exceeded. Blocks 6 and 7 are intended to prevent unnecessary energy being consumed by frequent unintentional or improper triggering of the first stage of prior checking. This is achieved in that after a predetermined number I _max1 of first _{signals_1} , which are not followed by a second signal_2, or after a predetermined parking period t _max, the first stage_1 of the prior check is only started with the second signal_2.

After the end of the first stage_1 of the prior check in block 8 , it is then checked in block 9 whether an error has occurred. If an error has been detected, a corresponding error message is generated in block 10 and the method is ended without start authorization. Depending on the type of error that has occurred, an emergency operation program can also be activated, making it possible to reach the next workshop. If no error was detected in block 9 , the flag_1 is assigned the value one in block 11 to identify a successfully completed first stage_1 and the number I 1 of the first stages_1 passed is increased by 1 in block 12 .

The process then jumps to the beginning of block 13 , where it is checked whether a second signal_2 has been received. The signal_2 is in turn generated by one or by the combination of several sensors which indicate the probability of an imminent start-up of the electric vehicle. However, the second signal_2 must indicate the upcoming commissioning with a higher probability than the first signal_1. If no signal_2 was received in block 13, the system jumps to block 25 , where it is checked whether the ignition lock has been actuated. If, on the other hand, a second signal_2 has been received in block 13 , the number 12 of the second stages_2 which have been completed so far is compared in block 14 with a second predetermined maximum number I _max2 . If the maximum number I _{max2 is} exceeded, the second part of the prior check is terminated and the system _jumps directly to the beginning of block 25 . If the maximum number I _max2 has not yet been reached, the variable I _{1 is reset} to the value zero in block 15 . This ensures that the first part of the preliminary check after passing through the second part regardless of the number I₁ of the previously passed first parts is released again in any case.

It is then checked in block 16 whether flag_1 has the value one. If this is the case, that is to say the first stage_1 of the prior check has been carried out without errors, the second stage_2 of the prior check is started in block 20 . In the other case, a branch is made to block 17 , where the first stage_1 is started and it is then checked in block 18 whether an error has occurred. If an error has been detected, an error message is generated in block 19 in accordance with block 10 and the method is ended. If, on the other hand, no error has occurred in block 18 , the process jumps to block 20 and the second stage_2 of the prior check is started. The next block then asks whether an error has occurred in the second stage_2 of the prior check. If this is the case, the process branches to block 22 , where an error message is generated in accordance with blocks 10 and 19 and the method is ended. Otherwise, the process jumps to block 23 , where flag_2 is assigned the value one to identify the successfully completed second stage_2 of prior checking. In block 24 , the number I₂ of runs through the second part of the preliminary check is then increased by one and then jumped to the beginning of block 25 .

In block 25 it is queried whether the ignition lock has been actuated. If no actuation was recognized, the process jumps back to the beginning of block 3 , where the method continues with the checking of the battery voltage U _bat . In the other case, it is checked in block 26 whether the flag_1 has the value one, that is to say whether the first stage_1 has already been passed without errors. If this is the case, the process jumps to block 30 , where it is checked whether the second stage_2 of the prior check has already been carried out without errors. If the second flag_2 also has the value one, the system then jumps to block 34 , where the start release is given.

If one of the flags in blocks 26 or 30 does not have the value one, the corresponding level of prior checking must be made up. For this purpose, a jump is made from block 26 to block 27 , where the first stage_1 of the prior check is started and then checked in block 28 for errors that have occurred. If an error is detected, an error message is generated in block 29 and the method ends. Accordingly, if the flag_2 has a value un equal to one, the process jumps from block 30 to block 31 and the second stage_2 of the prior check is started there, then checked for errors in block 32 and, if appropriate, an error message is generated in block 33 and the method is ended.

In the first stage_1 of the preliminary check, all tests are carried out processes that have low energy requirements through guided. Because even triggering this first stage several times cannot immediately lead to a power failure this first stage_1 by a very early characteristic Signal, for example a proximity or door handle sensor, to be triggered. In the second stage_2 prior checking then all energy-consuming steps are carried out, for example, the power electronics checked or the Power capacitors pre-charged. For the start of the second But stage_2 is a second characteristic signal_2 necessary, which is a higher probability for the imminent commissioning of the vehicle. Therefor comes for example a seat contact, a door light contact or a combination of several sensor signals in question. It's fine However, it is also possible that the second stage_2 only through the Start actuating the ignition lock.

When the vehicle is parked and there is sufficient energy supply, blocks 3 , 5 , 13 and 25 are normally run through in a loop. The method is ended in block 4 only if it is recognized in block 3 that the battery voltage U _{bat has} dropped below a minimum value U _min . If a proximity or a door handle sensor is activated and a first signal_1 is generated, the next loop pass from block 5 to the first part of the prior check starts at block 6 . Provided that no error is detected, the variables flag_1 and I₁ are assigned the value one and then jumped to block 13 . It is then checked here whether a second Signal_2 has been received in the meantime. If this is not the case, block 25 jumps back to the beginning of the method.

It can now happen that a first signal_1 is generated several times without a second signal_2 being subsequently received. In order to prevent the first stage_1 from being run through as often as required, blocks 6 and 7 are now used to check whether a predetermined number I _max1 of runs or a predetermined time period t _max has passed since the vehicle was put down. If one of these conditions is met, the first stage_1 is no longer run through from this point in time, but instead jumps directly to block 13 . Only when a second signal_2 is received and thereby the value I 1 is reset to the value zero in block 15 can the first stage_1 be run through again. If the predetermined time period t _{max has been} exceeded, the first stage_1 can only be started by the second signal_2.

When a second signal_2 is received, a branch is made from block 13 to the second part of the prior check from block 14 . Here, too, a maximum number of runs I _{max2 is specified} without subsequent actuation of the ignition lock. If this maximum number I _{max2 is} exceeded, the second part of the preliminary check can only be started by actuating the ignition lock. If, on the other hand, the maximum number I _max2 has not yet been reached, the second stage_2 is started in block 20 in any case. If, however, the first part of the prior check was not run without errors beforehand, the system jumps from block 16 to block 17 before the start of the second stage_2, where the first stage_1 of the prior check is also started.

If the ignition lock is finally actuated, the system branches from block 25 to block 26 . In this branch of the method, it is again checked whether the first stage_1 and the second stage_2 of the prior check were carried out without errors. If this is the case, the start approval for the electric vehicle is finally given in block 34 . If it is recognized in one of the blocks 26 or 30 that one of the stages has not yet been passed without errors, this is possibly made up for in blocks 27 and 31 respectively. The query in blocks 26 and 30 also ensures that the prior check is still carried out properly even if one or all sensors fail.

In this case, the driver would only have to press the Wait for the ignition lock to start for a while. Of the In this case, the driver can also use an additional Error messages about the failure of the sensors are informed.

Since the Flag_1 or the Flag_2 no information about when the respective level of prior checking was passed through, the flags can also be provided reset after a predetermined period of time. This could be prevented that the first stage_1 very long ago go through the actual startup process and is released and that this means that any that may occur in the meantime Faults could not be recognized.

Claims (3)

1. A method for prior checking and preparation of electrical components in electric vehicles, wherein the prior checking is started as a function of at least one sensor signal that characterizes the forthcoming start-up of the electric vehicle, characterized in that the prior checking takes place in two stages, the second stage (stage_2) being carried out by at least one a second sensor signal (Signal_2) is started, which indicates an imminent commissioning of the electric vehicle compared to the first sensor signal (Signal_1) with a higher probability, and that the less energy-intensive test processes take place in the first stage (Stage_1). 2. The method according to claim 1, characterized in that when a predetermined period of time (t _max ) has elapsed since the electric vehicle was switched off or a predetermined number (I _max1 ) of first sensor signals (Signal_1) were registered, the first stage ( Stage_1) is started only by a second sensor signal (Signal_2) or by actuating the ignition lock. 3. The method according to claim 3, characterized in that when a predetermined number (I _max2 ) of second sensor signals (Signal_2) has been registered, the second stage (Stage_2) is started only by opening the ignition lock.