A computer-implemented method and device for triggering a high-level communication between an electric vehicle and a charging station

The invention relates to a computer-implemented method and to a control device for triggering a high-level communication between an electric vehicle and a charging station. The electric vehicle comprises a control until for high-level communication between the charging station and the electric vehicle and for low-level communication between the charging station and the electric vehicles.

The basic communication is used to detect a connection between the charging station and the electric vehicle and to perform basic signaling between the electric vehicle and the charging station. The high-level communication is used to control the charging process of the electric vehicle. The basic signaling and the high-level communication is also explained in ISO and IEC 61851 standard documents. The basic signaling between the electric vehicle and the charging station and the high-level communication require different resources. The high-level communication requires higher communication resources which may cause higher power / current consumption and the low-level communication involves basic signaling which requires lower power I current consumption.

Standard control units which control the communication between the electric vehicle and the charging station have one microcontroller which controls the high-level communication and the low-level communication between the charging station and the electric vehicle. Such control units with one microcontroller have a relatively high power I current consumption during the charging process of the electric vehicle and also during normal operation of the electric vehicle when no connection is established between the electric vehicle and the charging station. In the letter case, the control unit is always activated just in order to capture a signal coming from the charging station or a connection of the electric vehicle to the charging station in order to start the charging process of the electric vehicle. This lasting activation of the control unit of the electric vehicle even when no connection is established between the electric vehicle and the charging station leads to a very high power consumption and current consumption of the control unit only to detect a connection of the electric vehicle to the charging station.

The object of the present disclosure is therefore to create a computer-implemented method and a control device which reduces energy consumption of the electric vehicle and I or increases the efficiency of the electric vehicle.

The object is achieved by a computer-implemented method comprising the features of the independent claims and by a control device which is used to execute the computer-implemented method according to the independent claim. Advantageous embodiments of the method and the control device are specified in the independent claims.

A computer-implemented method for triggering a high-level communication between an electric vehicle and a charging station is specified. The electric vehicle comprises a control unit with a first microcontroller for high-level communication between a charging station and the electric vehicle and a second microcontroller for basic communication between the charging station and the electric vehicle. According to the present disclosure, the control unit comprises two microcontroller each having its specific task. The first microcontroller has the task for high-level communication and the second microcontroller has the task for basic communication. The method for triggering the high-level communication between the electric vehicle and the charging station comprises the following steps:

- Operating only the second microcontroller of the control unit for detecting a wake-up signal coming from a possible connection of the electric vehicle to the charging station and keeping the first microcontroller deactivated. In other words, during normal operation of the electric vehicle for example during driving or standstill, the first microcontroller is deactivated and does not require any electric energy and only the second microcontroller is in operation for detection of a possible wake-up signal which comes from a possible connection of the electric vehicle to the charging station. The wake-up signal is a signal which is triggered from the connection of the electric vehicle to the charging station or which comes directly from the charging station when the plug from the charging station is inserted into the electric vehicle for charging. During normal operation of the electric vehicle, only the second microcontroller requires energy for the detection of the wake-up signal.

- Connecting the electric vehicle to the charging station, whereby at least one wake-up signal is sent to the control unit. In this step, the electric vehicle is connected to the charging station to recharge the electric vehicle. Due to the connection, the wake-up signal is sent to a control unit to start the communication between the control unit and the charging station to manage the charging process of the electric vehicle.

- Detecting the wake-up signal coming from the connection of the electric vehicle to the charging station with the second microcontroller. In this step, the second microcontroller detects the wake-up signal which comes from the connection of the electric vehicle to the charging station directly itself or which comes from the charging station. The second microcontroller is designed to detect the wake-up signal which comes from the connection of the electric vehicle to the charging station.

- Activating the first microcontroller for high-level communication between the electric vehicle and the charging station when the wake-up signal is detected. In other words, when the second microcontroller detects the wake-up signal which comes from the connection of the electric vehicle to the charging station, then the first microcontroller is activated, for example using the second microcontroller, for the required high-level communication between the electric vehicle to the charging station to initiate the recharging process of the electric vehicle.

According to the present disclosure, the tasks of high-level communication and the low-level communication is separated between the first microcontroller and the second microcontroller of the control unit for the charging process. The first microcontroller is responsible for the high-level communication which requires a high-power consumption and the second microcontroller is responsible for the basic communication between the charging station and the electric vehicle which does not require the high energy consumption. It is therefore possible to keep the first microcontroller deactivated for most of the operating time of the electric vehicle besides the actually charging process of the electric vehicle. This is achievable only using the second microcontroller which monitors if a wake-up signal coming from the connection of the electric vehicle to the charging station or which comes directly from the charging station. The overall power consumption of the control unit can therefore be reduced over the lifetime of the electric vehicle which therefore increases the range of the electric vehicle and the overall efficiency of the electric vehicle. According to one embodiment, it is conceivable that the microcontroller receives the wake-up signal from another control unit which predicts a future charging process coming for example from the navigation system which plans the recharging processes.

According to one embodiment, the second microcontroller operates using a polling sequence for the detection of the wake-up signal coming from the connection of the electric vehicle to the charging station. Polling is the process where the control unit waits for the external device to check for its readiness or state. In this embodiment, the polling sequence is used to detect the wake-up signal. With the polling sequence also the second microcontroller is not always activated. It is only activated when the polling sequence activates the second microcontroller. Therefore with the use of the polling sequence for the detection of the wake-up signal coming from the connection of the electric vehicle also the power consumption of the second microcontroller can be further reduced which increases the overall efficiency of the control unit and therefore the overall efficiency of the electric vehicle. The polling sequence for the detection of the wake-up signal helps therefore to achieve the desired efficiency of the control unit.

According to one embodiment, the polling sequence and the length of the wake-up signal are adjusted to each other in order that each wake-up signal is detected by the second microcontroller. The wake-up signal has a predefined length which is for example 100 milliseconds or 200 milliseconds. The polling sequence comprises highs and lows and the wake-up signal will be only detected by the second microcontroller when a high of the polling sequence and the wake-up signal occur at the same time. It is therefore necessary that a polling sequence is shorter than the length of the wake-up signal. In other words, the time between the highs and the lows of the polling sequence must be smaller than the overall length of the wake-up signal. In this case, at least one high of the polling sequence occurs which detects the presence of the wake-up signal coming from the connection between the electric vehicle and the charging station. It is therefore according to this embodiment simple and reliable to detect each wake-up signal coming from the connection between the electric vehicle and the charging station. Further, the adjustment of the polling sequence and the length of the wake-up signal creates a reliable and efficient method to detect each and every wake-up signal in combination with a low power consumption of the second microcontroller.

According to one embodiment, the polling sequence comprises a fast polling sequence and/or a slow polling sequence. According to this embodiment, the polling sequence may be a fast polling sequence, a slow polling sequence or a combination of a fast polling sequence and a slow polling sequence. The difference between the fast polling sequence and the slow polling sequence is that the fast polling sequence has a higher frequency than the slow polling sequence. For example, the fast polling sequence may have a five times higher frequency than the slow polling sequence. According to one embodiment, the fast polling sequence is used to detect a fast wakeup signals like button, flap or switches and the slow polling sequence is used to detect a slow wakeup signal I source like ADC inputs and control pilot signals from the charging station.

According to one embodiment, each polling sequence is implemented using a PWM signal on the second microcontroller. The PWM signal is a pulse width modulation signal with constant period time. The period of the slow polling sequence is for example five times longer than the period of the fast polling sequence. The PWM signal is in particular easy to implement on the second microcontroller and to achieve the desired advantage for the detection of the wake-up signal. It is therefore an easy and simple way to implement the required detection functionality on the second microcontroller for a reliable detection of the wake-up signal coming from the connection between the electric vehicle and the charging station.

According to one embodiment, the fast polling sequence is designed to capture a status of digital input and the slow polling sequence is designed to monitor a PWM signal from the charging station and/or ADC input signal from the charging station The digital inputs refer to switches and flaps which constitute the fast wakeup source monitored by fast polling sequence. The control pilot signal (PWM signal) and ADC are used for basic signaling and are monitored by the slow polling sequence. The communication standard only mentions control pilot and ADC, the fast polling sources are for example additional requirements which is to ensure the charger plug connection to the charging station is successful. This can be used based on requirements, since the implementation is generic so that all possible wakeup sources can be detected. According to one embodiment, the control pilot signal determines the connection status, voltage available for charging and charging status in case of AC charging in case of DC charging it produces a pulse of constant duty which indicates that the charging process must switch to high level communication. The specified design is implemented in such a way that different types of connectors with different fast wakeup signals and slow wakeup signals can be recognized by the same software thus, can be reused for multiple vehicles with minimum update.

According to one embodiment, the first microcontroller is activated via the second microcontroller by activating a power supply of the first microcontroller whereby the first microcontroller is woken up for the high-level communication between the electrical vehicle and the charging station. According to this embodiment, the first microcontroller or the control unit comprises a power supply for the first microcontroller. The activation of this power supply of the first microcontroller activates the first microcontroller for the desired high-level communication between the electric vehicle and the charging station. According to this embodiment, the second microcontroller just activates the power supply of the first microcontroller for the activation of the first microcontroller. It is thereby according to this embodiment in particular simple and reliable to activate the first microcontroller after the wake-up signal is detected from the connection between the electric vehicle and the charging station.

According to one embodiment, the second microcontroller switches to a transmit mode after detecting the wake-up signal, wherein in the transmit mode data from the connection of the electric vehicle to the charging station and/or high level communication data from and to the charging station is transmitted via the second microcontroller to and from the first microcontroller. In the transmit mode, the second microcontroller just transfers the data coming from the charging station to the first microcontroller and the data coming from the first microcontroller to the charging station. This reduces the required wiring and reduces the overall complexity of the control unit.

According to one embodiment, the second microcontroller records the wakeup signals during fast and slow polling. If data consistent with wakeup event, the wakeup of the first microcontroller is done. After first microcontroller was woken up, by request, the wakeup records from second microcontroller are sent to first microcontroller. According to this embodiment, data is collected within the second microcontroller and sent to the first microcontroller after the activation of the first microcontroller.

According to one embodiment, the communication between the first microcontroller and the second microcontroller is a synchronous to asynchronous communication from the first microcontroller to the second microcontroller. The communication is in request response format. The request is sent from the first microcontroller and the response is sent form the second microcontroller. A clock reference for the entire duration of the communication is given by the first microcontroller. The software implemented supports two types of format, one format which comprises 16 bytes format (16 clock pulses) and type two format which comprises 24 bytes format (24 clock pulses). The use of the particular type format depends on the functionality requested from the second microcontroller. The type two format is mainly used for a response which requires more than 8 bytes response. Those format types (type 1 and type 2) use 8 bytes for request and the remaining 8 or 16 bytes for response, this reduces the communication load on the second microcontroller. The idle time between request and response is greater than the maximum time required by the second microcontroller for execution of the request and collecting the data for a response. This is to ensure the correct response is ready before the second sequence of the clock pulse starts. The second microcontroller is in receive mode by default during start up and switches to transmit mode only when a response is to be sent to the request from the first microcontroller. Thus, with the above design synchronous to a synchronous communication between the first microcontroller and the second microcontroller is managed in a particular advantageous manner.

According to the present disclosure, it is possible to detect a connection between the electric vehicle and the charging station and to trigger the high-level communication between the control unit and the charging station between all different types of connectors, like Type 1 (IEC 62196 Type 1 ), Type 2 (IEC 62196 Type 2), CHAdeMO, Chaoji, China AC and China DC connectors between the electric vehicle and the charging station.

According to one embodiment, the wake-up signal is coming from the connection between the electric vehicle and the charging station as a PWM signal, also known as control pilot from the charging station. The control pilot may be used in both AC and DC charging. In AC charging it is used to determine the state of the station as the state defined in the standard IEC 61851 -1 . In DC charging it may also be used to force high-level communication.

The overall design of the control unit in combination with the charging station and the software design ensures a very low energy I current consumption of the control unit during the overall operation of the electric vehicle including during the charging process and further it ensures an individual control of all peripherals.

According to a further aspect of the present disclosure, a control device for triggering a high-level communication between an electric vehicle and a charging station is specified. The control device is for example part of the electric vehicle wherein the electric vehicle comprises a control unit with a first microcontroller for high-level communication between the charging station and the electric vehicle and a second microcontroller for basic communication between the charging station and the electric vehicle, wherein the control device is designed to execute a computer-implemented method according to anyone of the preceding claims. The control device may be the control unit or the second microcontroller itself. It is also conceivable that the control device is part of a control device of the electric vehicle or of the power train of the electric vehicle. It is also conceivable that the control device is implemented in a server architecture of the electric vehicle.

Further advantageous embodiments of the present disclosure will become apparent from the detailed description of the exemplary embodiments in connection with the figures.

In the figures:

Fig. 1 shows in a schematic manner a setup of a control unit of an electric vehicle according to a first exemplary embodiment,

Fig. 2 shows in a schematic manner a communication set up between the first microcontroller and the second microcontroller according to a first exemplary embodiment,

Fig. 3 shows in a schematic manner a fast polling sequence and a slow polling sequence according to a first exemplary embodiment.

Fig. 1 shows in a schematic manner a control unit 100 in an electric vehicle 10. The figure 1 shows further a charging station 20 for recharging the electric vehicle 10. The control unit 100 comprises a first microcontroller 110, and a second microcontroller 120. The first microcontroller 110 is designed to execute high-level communication between the charging station 20 and the electric vehicle 10. The second microcontroller 120 is designed to execute basic communication between the charging station 20 and the electric vehicle 10. The control unit 100 further comprises a first power supply 130 and a second power supply 140. The first power supply 130 is designed to provide electric energy for the first microcontroller 110 and the second power supply 140 is designed to provide electric energy for the second microcontroller 120. The first microcontroller 110 uses a synchronous communication 150 to an asynchronous communication 160 to the second microcontroller 120. This synchronous communication 150 to asynchronous communication 160 is also shown in figure 1.

For the synchronous communication 150 to asynchronous communication 160 clock pulse 190 is provided from the first microcontroller 110 to the second microcontroller 120 and data signals 180 are transmitted between the first microcontroller 110 and the second microcontroller 120. Figure 1 further shows a wake-up line 170 which goes from the second microcontroller 120 to the first power supply 130. Further, figure 1 shows a reset line 200 from the first microcontroller 110 to the second microcontroller 120 which is designed to reset the second microcontroller 120. Further, figure 1 shows an analog/digital line 210 between the second microcontroller 120 and the charging station 20. During normal operation of the electric vehicle 10 and the control unit 100, the first microcontroller 110 is deactivated and therefore in stand-by-mode. In this case, the first power supply 130 does not supply electric power to the first microcontroller 110. During this time, only the second microcontroller 120 is activated and the second power supply 140 provides electric energy to the second microcontroller 120. When the electric vehicle 10 is connected to the charging station 20, a wake-up signal is sent to the second microcontroller 120 through the analog/digital line 210. This wake-up signal is detected by the second microcontroller 120. The second microcontroller 120 may use a polling sequence which may comprise a fast polling sequence and a slow polling sequence for the detection of the wake-up signal coming from the connection between the electric vehicle 10 and the charging station 20. When the wake-up signal is detected by the second microcontroller 120, the power of the first power supply 130 is activated via the wake-up line 170 by the second microcontroller 120. The activation of the first power supply 130 activates the first microcontroller 110 and the high-level communication between the first microcontroller 110 and the charging station 20 may be activated or may start. The second microcontroller 120 may store the status of all wakeup sources during polling and when the status of wakeup sources is requested by first microcontroller 110 through synchronous communication 150 to asynchronous communication 160 based on the information received, the first microcontroller 110 may activate high level communication.

The figure 2 shows a communication diagram 300 between the communication of the first microcontroller 110 and the second microcontroller 120. The first microcontroller 110 uses synchronous communication 150 and the second microcontroller 120 uses asynchronous communication 160. The communication diagram 300 of this figure 2 shows a request from the first microcontroller 110 to the second microcontroller 120 and a response from the second microcontroller 120 to the first microcontroller 110. During the request, the first microcontroller 110 is in the transmit mode and the second microcontroller 120 is in the receive mode. The first microcontroller 110 sends clock pulse 190 to the second microcontroller 120 and the request using 8 bytes to the second microcontroller 120 through the data lines 180. During the request, the second microcontroller is in the receiving mode. In the response, still the first microcontroller 110 sends the clock pulse 190 to the second microcontroller 120 but the second microcontroller 120 sends the response to the first microcontroller 110 using 8 or 16 bytes depending on type 1 communication or type 2 communication through the data lines 180. During the response, the second microcontroller 120 is in a transmit mode and the first microcontroller 110 is in the receive mode.

Figure 3 shows a sequence diagram 400 with a fast polling sequence 410 and a slow polling sequence 420. The polling sequences 410, 420 are used and implemented within the second microcontroller 120 to detect the wake-up signal coming from the charging station 20 or coming from a connection of the electric vehicle 10 to the charging station 20. The sequence diagram 400 further shows a time axis 430. According to this embodiment, the polling sequences which is used for detection of the wake-up signal comprises the fast polling sequence 410 and the slow polling sequence 420. The fast polling sequence 410 and the slow polling sequence 420 are both PWM signals which are implemented in the second microcontroller 120. The full period of the first polling sequence 410, the small cycle 460 consists of the first time span T1 , the second time span T2 and the third time span T3. Those three time spans make up the small cycle 460. The pulse of the first polling sequence 410 is defined by the first time span T1 plus the second time span T2. The period of the slow polling sequence 420 comprises four small cycles 460 and one first time span T 1 , one second time span T2, one fourth time span T4, one fifth time span T5 and one second time span T6 and in addition, one third time span T3 minus a combination of the fourth time spanT4, the fifth time span T5 and the sixth time span T6. Five small cycles 460 make up a full command cycle 470 which comprises five pulses of the fast polling sequence 410 and one pulse of the slow polling sequence 420. During the time period T3, the control unit 100 is not able to detect the wake-up signal, only during the active time period T1 and T2 which defines the pulse of the PWM signal of the fast polling sequence 410. In order to detect each wake-up signal, the wake-up signal length must be longer than the time span T3. For example, if the wake-up signal has a length of 200ms, the time span T3 has for example a length of 120ms. In this case, each and every wake-up signal passes a least one pulse defined by the time span T1 and T2 of the fast polling sequence 410 which allows the second microcontroller 120 the detection of the wake-up signal and therefore to trigger the high-level communication. According to this embodiment, the fast polling sequence 410 reads digital signals and the slow polling sequence 420 reads analog signals coming from the charging station 20. The fast polling sequence 410 is able to capture all fast wake up sources like switches flap and button and the slow polling sequence 420 is used for monitoring the control pilot signal and ADC inputs used for basic signaling thus having combination of both polling sequences 410, 420 allows to detect all wakeup sources for the electric vehicle 10 for charging and also low level basic signaling can be accomplished in a relatively simple manner.

According to one embodiment, the pulses of the fast polling sequence 410 do not overlap with the pulse of the fast polling sequence 420, this is also shown in figure 3. According to one embodiment, the slow polling sequence 420 monitors all possible ADC sources for a particular type of charger along with the control pilot PWM signal. The timing parameters for the fast polling sequence 410 and the slow polling sequence 420 are configurable depending on the requirements.

The first Node 431 , the fourth node 434, the seventh node 437, the tenth node 440 and the thirteenth node 443, generates the switch on and the third node 433, the sixth node 436, the nineth node 439, the twelfth node 442 and the fifteenth node 445 will generate the switch off of the fast polling sequence 410 with specific delays. The second node 432, the fifth node 435, the eight node 438, the eleventh node 441 and the fourteenth node 444 will read the digital inputs during the fast polling sequence high times. The sixteenth node 446 and the eighteenth node 448 generate the pulse of the slow polling sequence 420 and the seventeenth node 447 will read the analogue signals with required timings.

Analog and control pilot signal will be, according to this embodiment, captured during the pulse of the slow pulling sequence 420 (seventeenth node 447) The time between the eighteenth node 448 and the first node 431 should be (T3-(T4+T5+T6)) to ensure no overlapping of the pulses of the fast polling sequence 410 and the pulse of the slow polling sequence.