BR102019008798A2 - communication of combined speed and synchronization signals between vehicle control units - Google Patents

Abstract

Communication of combined speed and synchronization signals between vehicle control units The present invention relates to techniques in the context of vehicles and, in particular, to methods for communicating speed and synchronization signals between control units in a vehicle. according to a first aspect, the description refers to the first control unit for use in a vehicle. the first control unit comprises a set of control circuits 11, an internal clock 16, an input 13 and one or more outputs 14, 15. input 13 is configured to receive, from a speed sensor, a speed signal comprising a pulse train corresponding to the speed of an object rotating in the vehicle. the one or more outputs 14, 15 are configured to allow transmission to a second control unit. the control circuitry 11 is configured to generate a combined synchronization and speed signal incorporating a first synchronization message into an incoming speed signal received at the entrance and to generate a second synchronization message, wherein the first message synchronization and the second synchronization message together, indicate a timing of the internal clock. the control circuitry 11 is also configured to transmit the first synchronization message and the second synchronization message to the second control unit on one or more outputs. the present description also refers to a second control unit, corresponding methods, a power train and a vehicle comprising the control units and a computer program.

Description

“COMMUNICATION OF COMBINED SYNCHRONIZATION AND SPEED SIGNS BETWEEN VEHICLE CONTROL UNITS”

Field of the Invention [0001] The present description refers to techniques in the context of vehicles and, in particular, to methods for communicating synchronization and speed signals between control units in a vehicle. The present description also refers to corresponding control units, a vehicle comprising the control units and a computer program.

Fundamentals of the Invention [0002] An Electric Control Unit, ECU, is an embedded electrical device, basically a digital computer that controls one or more electrical systems (or electrical subsystems) of a vehicle based, for example, on information read from sensors located in different parts and different components of the vehicle. In more advanced vehicles, such as buses, trucks, work vehicles and advanced cars; a network such as a CAN (Controlled Area Network) network is used to handle communication between multiple ECUs in the vehicle. ECUs that are connected to the CAN can handle a large number of functions in the vehicle. These are, for example, functions related to gear shifting, steering, engine control, braking, climate control systems, lighting, driver comfort, alarms and safety.

[0003] As of today, the electrical systems of a vehicle in general are not synchronized. Typically, each ECU has its own internal clock. Each electrical system usually also has its own sensors. For example, the engine system may have a speed sensor and the gear system may have a speed sensor. Alternatively, sensor data, for example, a speed signal, is sent over a bus, such as the CAN bus, Control Area Network. However, the CAN bus is a priority-based bus and, due to other traffic on the bus, it is not certain when messages will be sent. Thus, using only the CAN bus to communicate the

Petition 870190040802, of 30/04/2019, p. 9/43

2/25 speed, makes the speed signal non-deterministic and the update frequency will be low, which limits the usefulness of the speed signal.

Summary of the Invention [0004] It is an objective of the description to alleviate at least some of the drawbacks of existing solutions. It is yet another objective to provide improvements for ECU signaling to ECU signaling in a vehicle, at least related to improving the accuracy in the communication of speed and synchronization signals between the control units in a vehicle. Another goal is to achieve this with the limited addition of additional hardware.

[0005] According to a first aspect, the description refers to the first control unit for use in a vehicle. The first control unit comprises a set of control circuits, an internal clock, an input and one or more outputs. The input is configured to receive, from a speed sensor, a speed signal that comprises a train of pulses corresponding to the speed of an object in rotation in the vehicle. The one or more outputs are configured to allow transmission to a second control unit. The control circuitry is configured to generate a combined speed and synchronization signal incorporating a first synchronization message into an incoming speed signal received at the entrance, to generate a second synchronization message, in which the first synchronization message and the second synchronization message together indicates a timing of the internal clock, and to transmit the first synchronization message and the second synchronization message to the second control unit on one or more outputs. In this way, the time synchronization between the first and the second control unit is activated with minor hardware modifications (an extra input / output (I / O)). At the same time, it is possible to communicate a speed signal from the first control unit to the second control unit. The speed signal can be used to detect, for example, power train fluctuations, clutch slippage, etc. One of the functions alone may not motivate extra I / O. However, using a wire for both purposes makes it a much better case.

Petition 870190040802, of 30/04/2019, p. 10/43

3/25 [0006] In some embodiments, the one or more outputs comprise a single wire output port, and the control circuitry is configured to transmit the combined synchronization and speed signal on the single wire output port. In this way, both the synchronization signal and the speed signal can be communicated using only one additional output (ie, dedicated I / O).

[0007] In some embodiments, the control circuit is configured to interpret the received speed signal and the control circuit is configured to generate and / or transmit the first and second synchronization messages in response to the interpretation of the received speed signal . Therefore, the errors that can occur at the start will not be present in the combined speed and synchronization signal.

[0008] In some embodiments, the one or more outputs comprise a communication bus interface and the control circuitry is configured to transmit the second synchronization message on the communication bus interface. The second synchronization message that is transmitted on a communication bus can simplify the synchronization information that needs to be transferred in the first synchronization message. The second synchronization message can also increase the accuracy of the synchronization.

[0009] In some embodiments, the first synchronization message is a synchronization pattern and the second synchronization message indicates a relationship between the synchronization pattern and the internal clock. In this way, the timing of the internal clock can be estimated by a second receiving control unit.

[0010] In some modalities, the set of control circuits is configured to incorporate both the first synchronization message and the second synchronization message in the combined synchronization and speed signal. Thus, all the information necessary for communicating synchronization and speed information can be transmitted on a single wire.

[0011] In some modalities, the first synchronization message is an arrival synchronization pattern that indicates that an actual synchronization will occur

Petition 870190040802, of 30/04/2019, p. 11/43

4/25 within a predefined time and the second synchronization message is a synchronization pattern that indicates the timing of the internal clock. The arrival synchronization pattern mitigates signal errors on the receiving side.

[0012] In some embodiments, the first control unit is a master control unit and the second control unit is a servo control unit of the first control unit.

[0013] In some modalities, the control circuitry comprises real-time processing hardware configured to generate the combined speed and synchronization signal. In this way, the combined speed and synchronization signal can be generated with negligible delay.

[0014] According to a second aspect, the description refers to the second control unit for use in a vehicle. The second control unit comprises an internal clock, an input, and a control circuitry. The input configured to receive, from a first control unit, a combined signal of synchronization and speed comprising a train of pulses with a frequency corresponding to the speed of an object in rotation in the vehicle, and the set of control circuits is configured to detect a first synchronization message, incorporated into a combined synchronization and speed signal received at one or more inputs, to receive a second synchronization message from the first control unit, and to determine a timing of an internal clock of the first control unit, based on the first synchronization message and the second synchronization message. In this way, the second control unit can receive synchronization and speed information from the first control unit with small hardware additions.

[0015] In some modalities, the set of control circuits is configured to adjust a timing of an internal clock of the second control unit based on the determined timing. Thus, subsystems can operate in synchronization and unnecessary delays can be avoided.

[0016] In some modalities, the one or more entries comprise a

Petition 870190040802, of 30/04/2019, p. 12/43

5/25 single wire input port configured to receive the combined speed and synchronization signal from the first control unit.

[0017] In some modalities, the control circuitry is configured to detect a predetermined pulse sequence in the combined synchronization and arrival speed signal.

[0018] In some modalities, the control circuitry is configured to ignore pulse sequences with a frequency above a predefined limit value.

[0019] In some embodiments, the one or more inputs comprise a communication bus interface and the set of control circuits is configured to receive the second synchronization message on the communication bus interface. In some embodiments, the first synchronization message is a synchronization pattern, and the second synchronization message indicates a relationship between the synchronization pattern and the internal clock of the first control unit.

[0020] In some modalities, the set of control circuits is configured to detect a second synchronization message being incorporated into the combined synchronization and arrival speed signal. In some embodiments, the first synchronization message is an incoming synchronization pattern that indicates that an actual synchronization will occur within a predefined time and the second synchronization message is a synchronization pattern that indicates the timing of the internal clock of the first synchronization unit. control.

[0021] According to a third aspect, the description refers to a power train comprising the first control unit and the second control unit. In this way, the engine speed can, for example, be communicated to the gear system, so that the slip of the clutch can be estimated. By tracking the clutch slip, the power train ECUs can estimate the torque transferred during a start in which the slip could be recalculated from the transferred torque. Winding detection

Petition 870190040802, of 30/04/2019, p. 13/43

6/25 static torque can be recalculated to the current transferred torque with the clutch type and clutch wear information. In addition, micro-slip can be used while driving to isolate engine oscillations. So, it may also be desirable to monitor the micro-slip.

[0022] According to a fourth aspect, the description refers to a vehicle that comprises the power train of the third aspect.

[0023] In accordance with a fifth aspect, the description refers to a method, for use in a first control unit in a vehicle, to communicate synchronization and speed information to a second vehicle control unit. The first control unit has an internal clock. The method comprises receiving, from a speed sensor, a speed signal comprising a pulse train with a frequency corresponding to the speed of an object in rotation in the vehicle and generating a combined signal of synchronization and speed incorporating a first message of synchronization in the received speed signal. The method further comprises generating a second synchronization message, in which the first synchronization message and the second synchronization message together indicate a timing of the internal clock and transmit the combined synchronization and speed signal and the second synchronization message to the second synchronization unit. control.

[0024] In some modalities, the first synchronization message is a predetermined pulse sequence incorporated in the combined synchronization and speed signal.

[0025] In some modalities, the method comprises interpreting the received speed signal, and the generation and / or transmission is performed in response to the interpretation.

[0026] In some modalities, the second synchronization message is also incorporated in the combined synchronization and speed signal.

[0027] In some modalities, the first synchronization message is an arrival synchronization pattern that indicates that an actual synchronization will occur

Petition 870190040802, of 30/04/2019, p. 14/43

7/25 within a predefined time and the second synchronization message is an actual synchronization pattern that indicates the timing of the internal clock.

[0028] In some modalities, the second synchronization message is a message transmitted on a vehicle communication bus.

[0029] In some modalities, the first synchronization message is a synchronization pattern, and the second synchronization message indicates a relationship between the internal clock and the synchronization pattern.

[0030] In some modalities, the transmission comprises the transmission of the combined signal of synchronization and speed between the ECUs of the power train.

[0031] According to a sixth aspect, the description refers to the method, for use in a second vehicle control unit, to receive synchronization and speed information from a first vehicle control unit. The method comprises receiving, from the first control unit, a combined synchronization and speed signal comprising a pulse train with a frequency corresponding to the speed of an object in rotation in the vehicle, and detecting a first synchronization message incorporated in the signal combined synchronization and speed received. The method further comprises receiving a second synchronization message from the first control unit and determining a timing of an internal clock of the first control unit, based on the first synchronization message and the second synchronization message.

[0032] In some modalities, the method comprises adjusting the timing of an internal clock of the second control unit based on the specific timing.

[0033] In some embodiments, the method comprises detecting a predetermined pulse sequence in the combined synchronization and arrival speed signal. In some embodiments, the detection comprises ignoring pulse sequences with a frequency above a predefined threshold value.

[0034] In some modalities, receiving the second message of sin

Petition 870190040802, of 30/04/2019, p. 15/43

8/25 timing comprises receiving the second synchronization message on a communication bus. In some embodiments, the first synchronization message is a synchronization pattern, and the second synchronization message indicates a relationship between the synchronization pattern and an internal clock timing of the first control unit.

[0035] In some modalities, receiving the second synchronization message comprises detecting a synchronization pattern being incorporated into the combined synchronization and speed signal. In some embodiments, the first synchronization message is an incoming synchronization message and the second synchronization message is a synchronization pattern that indicates a timing of the internal clock of the first control unit.

[0036] According to a seventh aspect, the description refers to a computer program that comprises instructions that, when the program is executed by a computer, cause the computer to perform any of the methods described above and below.

[0037] According to an eighth aspect, the description refers to a computer-readable medium comprising instructions that, when executed by a computer, cause the computer to perform any of the methods described above and below.

Brief Description of the Drawings [0038] Figure 1 illustrates a vehicle in which the proposed control units and methods can be used.

[0039] Figure 2 illustrates a vehicle power train in figure 1.

[0040] Figure 3 illustrates a sprocket sensor.

[0041] Figure 4 illustrates the communication between a first and a second control unit, according to a first exemplary modality.

[0042] Figure 5 illustrates the communication between a first and a second control unit, according to a second exemplary mode.

[0043] Figure 6 illustrates the internal clock of the first control unit and the internal clock of the second control unit.

Petition 870190040802, of 30/04/2019, p. 16/43

9/25 [0044] Figure 7 illustrates the synchronization of the internal clock of the second control unit.

[0045] Figure 8 illustrates a first control unit according to some modalities.

[0046] Figure 9 illustrates a second control unit according to some modalities.

[0047] Figure 10 illustrates a method performed on a first control unit according to some modalities.

[0048] Figure 11 illustrates a method performed on a second control unit according to some modalities.

Detailed Description of the Invention [0049] It is generally desirable to synchronize the internal clocks of a vehicle's subsystems to avoid unnecessary delays and to have the subsystems control units working in sync.

[0050] In addition, it may be necessary to communicate speed information between subsystems in a vehicle with high precision. One reason for communicating speed information between control units in a vehicle is to be able to detect power train fluctuations, such as clutch slippage. The slip of the clutch can basically be detected by comparing the rotation of the engine shaft with the rotation of the corresponding shaft on the gearbox side. However, the engine and gearbox typically belong to separate electrical subsystems in the vehicle. Thus, to determine the clutch slip accurately, the measurement of the engine speed on the engine side needs to be communicated to the gearbox subsystem.

[0051] It is generally desirable to limit the number of extra wires between the control units. Therefore, it can be difficult to motivate an additional thread for each of these functions. Therefore, it is proposed here to design an Electric Control Unit, ECU, to transfer synchronization and speed information on a single wire. This solution is useful in a system that comprises at least two control units, where one typically acts as a master and the others are servants. In the proposed solution,

Petition 870190040802, of 30/04/2019, p. 17/43

10/25 the master ECU has a speed signal input that is interpreted by the master ECU and sent as a digital pulse train with a frequency corresponding to a measured rotating object speed. Also included in the signal is a synchronization message. This synchronization signal can be used to synchronize / compensate the clock of the servo ECUs.

[0052] The proposed solution requires only one additional wire (or input / output, I / O) per control unit, the rest of the implementation is handled by the software. However, there are two reasons for this extra I / O between ECUs. One is to provide a sync signal to match / compensate for the ECU's internal clocks to avoid unnecessary delays and get the ECUs to work in sync. The other is to communicate accurate information about a rotating object. One of the functions alone may not motivate the extra yarn, but using a yarn for both purposes is the best case.

[0053] Figure 1 illustrates a vehicle 1 in which the proposed control units and methods can be used. The vehicle 1 of Figure 1 comprises a power train 2. Vehicle 1 can, for example, be a working vehicle such as a truck, bus or other heavy vehicle; or vehicle 1 can be a normal car.

[0054] Figure 2 illustrates a vehicle power train in Figure 1 in more detail. The power train comprises a power supply, here an engine 3, a motor shaft 4 and a clutch 5, a gearbox 6, a gear input shaft 7 and a drive shaft 8. The force generated by the motor 3 is transported from the engine shaft 4, through the clutch 5 and the gearbox 6 to the drive shaft 8 that drives the wheels of the vehicle 1. The clutch 5 is, for example, a friction clutch comprising one or more disks with friction linings that are pressed against a steel plate, for example, by powerful springs and a pressure plate, resulting in a direct drive between engine 3 and gearbox 6 when vehicle 1 is running. However, if there is not enough friction on clutch 5, the speed of the power supply may increase without a corresponding increase in road speed. This is, in general, a defective condition, which can be estimated by comparing the speed of the motor shaft 4

Petition 870190040802, of 30/04/2019, p. 18/43

11/25 with the speed of the input shaft 7. Sometimes, the micro-slip (that is, the clutch slip is very small) is purposely introduced, for example, when trying to attenuate the oscillations of the traction system. However, micro-slip should always be a chosen mode of operation, that is, it is not something that happens by chance. When micro-slip is intentional, then clutch 5 is not fully closed on purpose.

[0055] Engine 3 and gearbox 6 are typically controlled by separate electrical subsystems, each subsystem comprising one or more ECUs, here called control units. For simplicity, it is assumed in this example that each subsystem comprises only one ECU. More specifically, engine 3 is controlled by a first control unit 10 and gearbox 6 is controlled by a second control unit 20. The first and second control units 10, 20 will be further described with reference to Figure 8 and Figure 9.

[0056] The power train also comprises a speed sensor 30, configured to detect the engine speed. Figure 3 illustrates an exemplary embodiment in which the speed sensor 30 is a gear sensor. The sprocket sensor sweeps a sprocket 31, arranged on the motor shaft 4. The sprocket sensor can, for example, comprise two hall effect sensors, a rare earth magnet and an appropriate evaluation electronics. The magnet's field is modulated by the passing target teeth. This modulation is registered by Hall sensors, converted by a comparison stage to a square wave signal S and amplified in a drive stage.

[0057] The signal S generated by the speed sensor 30 has a period corresponding to a gear tooth of the sprocket 31 and in some embodiments it also comprises additional position information about where in the cycle the sprocket 31 is, for example, indicated by one or more long pulses 33 caused by one or more long teeth 32 on the sprocket 31 positioned at predetermined positions on the sprocket 31. Thus, based on the generated signal, the first control unit 10 can determine the motor speed as well like where in the cycle is the engine.

Petition 870190040802, of 30/04/2019, p. 19/43

12/25 [0058] The proposed technique will now be described with reference to the first control unit 10 and a second control unit 20 in Figure 2. However, it should be appreciated that the solution can be used for any control units in a vehicle, when it is desired to communicate synchronization and speed information. In the proposed solution, an additional wire is added between the first control unit 10 and the second control unit 20, in order to be able to route a speed signal between the control units 10, 20. It is also proposed to incorporate information synchronization in the speed signal, such that the synchronization between the first control unit 10 and the second control unit 20 is also enabled. The synchronization information comprises a first and a second synchronization message. There are different ways to implement synchronization messages. Two exemplary implementations will now be described with reference to Figures 4 and 5.

[0059] Figure 4 illustrates the communication between a Master ECU, here also called the first control unit 10, and a Serva ECU, here also called the second control unit 20, according to a first exemplary modality. In this example, the transmission of two synchronization messages (a first and a second synchronization message) is periodically triggered by the Master ECU, for example, every 1000 ms. Thus, the Serva ECU can synchronize its internal clock with the internal clock of the Master ECU, observing the synchronization messages and adjusting its internal clock accordingly.

[0060] The first M1 synchronization message is an incoming synchronization pattern and the second M2 synchronization message is an actual synchronization pattern. The arrival synchronization pattern indicates that an actual synchronization pattern will occur within a specified time limit. The arrival synchronization pattern is, for example, inserted into the pulse train, replacing a long pulse with a specified pattern, for example, several short pulses. The purpose of the arrival synchronization pattern is to increase robustness and make errors less likely. The current synchronization pattern is inserted here replacing a short pulse (standard tooth) with two short pulses. The actual synchronization pattern is triggered

Petition 870190040802, of 30/04/2019, p. 20/43

13/25 when the clock on the Master ECU reaches a predefined value. The default value is, for example, 0, when the ECU Master clock is cycled from 0 to 2048.

[0061] Figure 5 illustrates an alternative implementation of a first synchronization message comprising a synchronizing pattern periodically triggered by the master ECU, for example, 10 ^to each motor revolution. In this example, the Serva ECU can synchronize its clock with the ECU Master clock by observing the synchronization pattern and a second corresponding synchronization message that is transmitted by the CAN.

[0062] In this example, the first M1 synchronization message is a synchronization pattern and the second M2 'synchronization message is a CAN message. Thus, in this mode, only one synchronization pattern is transmitted. This pattern indicates that a synchronization event has occurred. The synchronization pattern is indicated on the pulse train, replacing a long pulse with a specified pattern, for example, several short pulses. When the synchronization event is triggered, a corresponding CAN message is also sent from the Master ECU to the Serva ECU. The CAN message contains information associated with the synchronization pattern, for example, the number of engine revolutions and the time elapsed since the last synchronization event.

[0063] By combining the time that the synchronization pattern was received with the information in the corresponding CAN message, the ECU Serva can estimate its clock deviation.

[0064] Figure 6 illustrates the internal clock 16 of the first control unit 10 and the internal clock 26 of the second control unit 20 when it is out of synchronization.

[0065] Figure 7 illustrates the synchronization of the internal clock of the second control unit. By identifying a time t (corresponding to a known default value, for example, 0) of the internal clock 16 of the first control unit 10, the second control unit 20 can estimate its clock deviation. The second control unit 20 can then gradually (that is, with a maximum rate of change) adjust its own internal clock 26 to be in synchronization with the internal clock

Petition 870190040802, of 30/04/2019, p. 21/43

14/25 of the first control unit 10. By doing this gradually, intermittent errors will be mitigated.

[0066] An exemplary implementation of the first control unit 10 of vehicle 1 of Figure 1 will now be described with reference to Figure 8. The first control unit 10 is configured to communicate synchronization and speed information to a second control unit 20 of the vehicle 1. In some embodiments, the first control unit 10 is a master control unit and the second control unit 20 is a servo control unit of the first control unit 10.

[0067] The first control unit 10 comprises a set of control circuits 11, a memory 12, an input 13, an output 14, a communication bus 15 and an internal clock 16. The first control unit 10 also typically comprises a plurality of other I / O components and interfaces. However, for simplicity, only the components and I / O interfaces needed to explain the proposed technique will now be described.

[0068] The internal clock 16 measures the functionality of the first control unit 10. The internal clock 16 can, for example, be used to record the measurement data received at input 13.

[0069] Entry 13 is a single wire entry port. Input 13 is configured to receive a signal from another component in the vehicle, for example, a sensor. It is implied that the first control unit 10 and the other component are connected to a common ground. For example, input 13 is arranged to receive a speed signal comprising a pulse train corresponding to the speed of an object in rotation in vehicle 1 from a speed sensor 30. The object in rotation is, for example, a sprocket 31 coupled to an axis in vehicle 1, for example, to the motor axis 4. However, the solution would also work to measure the revolution of other axes and other rotating objects.

[0070] Output 14 is a signal wire output port, which is configured to be connected to a second control unit 20. When the first control unit 10 is installed in vehicle 10, then output 14 is typically electrically

Petition 870190040802, of 30/04/2019, p. 22/43

15/25 connected to a corresponding input 23 (Figure 9) of the second control unit 20 by a single wire. In other words, output 14 is configured to allow transmission of a signal to a second control unit 20. As explained above, it is implied that the first control unit 10 and the second control unit 20 have a common ground.

[0071] The communication bus interface 15 is a generic interface that is used to manipulate the communication between several control units in the vehicle 1. The communication bus comprises one or more wires, where the control units in a vehicle can meet communicate with each other using a standardized protocol. In other words, the communication bus 15 serves as both an input and an output. The Control Area Network bus, CAN, commonly used is an example of a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other.

[0072] In an exemplary implementation in vehicle 1, the first control unit 10 and the second control unit 20 communicate via the communication bus. In addition, output 14 of the first control unit 10 is electrically connected (for example, by an electrical wire) to input 23 of the second control unit 20.

[0073] The control circuitry 11 typically comprises a microprocessor. The control circuitry 11 is configured to cause the first control unit 10 to perform all aspects of the method (Figure 10) performed by a first control unit 10 described herein. This is typically done by executing a computer program code stored in memory 12. Memory 12 is, for example, EPROM or a Flash memory.

[0074] When a speed signal is received at input 13, then the control circuitry 11 reads and modifies the received speed signal. More specifically, the control circuitry 11 is configured to generate a combined speed and synchronization signal incorporating a first M1 synchronization message into a speed arrival signal received at input 13. In

Petition 870190040802, of 30/04/2019, p. 23/43

16/25 some modalities, the first M1 synchronization message is positioned at a predefined position on the pulse train. For example, it is incorporated into a long pulse of the speed signal. The control circuitry 11 is also configured to generate a second M2 synchronization message. The second M2 synchronization message comprises additional synchronization information. The second M2 synchronization message is, in some modalities, also incorporated in the combined synchronization and speed signal. Alternatively, it is transmitted in another way, for example, on a communication bus. The first synchronization message M1 and the second synchronization message M2 together indicate a timing of the internal clock. As described in conjunction with Figure 4 and Figure 5, this can be implemented in different ways.

[0075] In some embodiments, the control circuitry 11 is configured to incorporate both the first M1 synchronization message and the second M2 synchronization message in the combined speed and synchronization signal. In some embodiments, the first synchronization message M1 is an arrival synchronization pattern that indicates that an actual synchronization will occur within a predefined time and the second synchronization message M2 is a synchronization pattern that indicates the timing of the internal clock 16. For example, already briefly described in conjunction with Figure 4, the first M1 synchronization message is an arrival synchronization pattern preparing the second control unit 20 for a synchronization pattern that will appear in the near future. The second synchronization message is then the actual synchronization pattern, which indicates the timing of the internal clock 16 of the first control unit 10. The actual synchronization pattern occurs at a specific point in time, for example, when the internal clock 16 of the first control unit 10 is 0. The arrival synchronization pattern is not dependent on the timing of the internal clock 16 of the first control unit. Thus, the arrival synchronization pattern is, for example, mapped to the nearest long pulse (see Figure 3) before the actual synchronization pattern. Thus, the arrival synchronization pattern is easier for the second control unit to detect, as it will always appear on a pulse

Petition 870190040802, of 30/04/2019, p. 24/43

17/25 “long”. The arrival pulse will make it easier for the second control unit 20 to find the actual timing, which may be a shorter pulse pattern.

[0076] In some other modalities, the first M1 synchronization message is a synchronization pattern and the second M2 synchronization message indicates a relationship between the synchronization pattern and the internal clock 16. Described differently, as already briefly described in relation to Figure 5 above, the first M1 synchronization message is, in some embodiments, a synchronization pattern that indicates the timing of the internal clock 16. The second M2 synchronization message then comprises additional information that is necessary to interpret the first M1 synchronization message. . Examples of such information are the number of clock strings (from internal clock 16) that have elapsed between a specific time and the synchronization message or number of clock strings that have elapsed since the last transmitted synchronization message. Alternatively, the information defines the time of the internal clock of the first control unit, when the synchronization pattern was transmitted. With this solution, the synchronization pattern does not need to be transmitted at a certain point in time (from internal clock 16). Thus, the synchronization pattern can always be mapped to a “long” pulse, which will increase stability.

[0077] The control circuitry 11 is further configured to transmit the first synchronization message M1 and the second synchronization message M2 to the second control unit 20 on one or more outputs 14, 15. If both synchronization messages are pulse patterns embedded in the speed signal (Figure 4), this step basically corresponds to transmitting the speed signal with the pulse sequences incorporated (or inserted) in output 14.

[0078] However, if the second M2 synchronization message is a communication message, then the communication bus interface 15, which then serves as an output, is also used. In other words, in some embodiments, the control circuitry 11 is configured to transmit the second synchronization message M2 on the communication bus interface 15.

[0079] It may be desirable to wait to start transmitting messages from

Petition 870190040802, of 30/04/2019, p. 25/43

18/25 synchronization until the first control unit 10 has learned what the sprocket looks like and finding the position on the wheel. In other words, in some embodiment, the control circuitry 11 is configured to interpret the received speed signal and the control circuitry is configured to generate and / or transmit the first and second synchronization messages in response to the interpretation of the received speed signal.

[0080] In some embodiments, the control circuitry 11 comprises real-time processing hardware configured to generate the combined speed and synchronization signal. In other words, the proposed solution may require time processing hardware in the microprocessor to handle signal processing without causing long delays.

[0081] Figure 9 illustrates a second corresponding control unit 20 for use in vehicle 1 of Figure 1, according to some modalities. The second control unit 20 is configured to receive synchronization and speed information from a first control unit 10 in vehicle 1, for example, the first control unit in Figure 8. In some embodiments, the second control unit 20 it is a servo control unit of the first control unit 10 which is a master control unit.

[0082] The second control unit 20 comprises a set of control circuits 21, a memory 22, an input 23, a communication bus interface 25 and an internal clock 26a. The second control unit 20 typically also comprises a plurality of other components and I / O interfaces. However, for simplicity, only the components and I / O interfaces needed to explain the proposed technique will now be described. In an exemplary implementation on vehicle 1, the first control unit 10 and the second control unit 20 communicate via the CAN bus. In addition, output 14 of the first control unit is electrically connected (for example, by an electrical wire) to input 23.

[0083] The internal clock 26 measures the functionality of the second control unit 20. The internal clock 26 can, for example, be used to record the data of

Petition 870190040802, of 30/04/2019, p. 26/43

19/25 measurement received at input 23.

[0084] Input 23 is a single wire port configured to receive, for example, the signal transmitted at output 14 (Figure 9). In other words, input 23 is configured to receive, from the first control unit 10, a combined synchronization and speed signal comprising a pulse train with a frequency corresponding to the speed of an object in rotation in the vehicle 1.

[0085] The communication bus interface 25 is a generic interface that is used to manipulate the communication between several control units in the vehicle 1. The communication bus comprises one or more wires, where the control units in a vehicle can meet communicate with each other using a standardized protocol. In other words, the communication bus interface 25 acts as an input and an output. An example of such an interface is the commonly used CAN bus.

[0086] The control circuitry 21 typically comprises a microprocessor. The control circuitry 21 is configured to cause the control circuitry 21 to perform all aspects of the method (Figure 11) performed by a second control unit 20 described below. This is typically done by executing computer program code stored in memory 22. Memory 22 is, for example, EPROM or a Flash memory.

[0087] The control circuitry 21 is configured to detect a first M1 synchronization message, incorporated in a combined synchronization and arrival speed signal received at input 23. For example, the control circuitry 21 is configured to detecting a predetermined pulse sequence in the combined synchronization and arrival speed signal.

[0088] According to some modalities, the control circuitry 21 is configured to ignore pulse sequences having a frequency above a predefined limit value. Since the first M1 synchronization message typically corresponds to a predetermined position on the sprocket, the second control unit is aware of when the synchronization event may appear.

Petition 870190040802, of 30/04/2019, p. 27/43

20/25 recer and, in addition, by limiting the maximum allowed acceleration of the sprocket, the wrong decoding of the signal can be avoided. More specifically, since the current speed of the rotating object is known and the maximum acceleration in the rotating object is also known, the expected time intervals and the minimum time interval of the combined synchronization and speed signal can be calculated. To allow robust detection, the built-in synchronization pattern must be designed to have shorter time intervals than the minimum time intervals. If the combined speed and synchronization signal comprises even shorter time intervals, then it is considered disturbance or noise. Thus, the synchronization pattern can be monitored at an interval limited by the speed of the rotating object and the acceleration and time intervals of the synchronization pattern defined by the project. Therefore, it is possible to filter signals that are not possible synchronization patterns.

[0089] The control circuitry 21 is configured to receive a second M2 synchronization message from the first control unit 10. As explained above, the second M2 synchronization message is, in some embodiments, an embedded pulse pattern. on the received speed signal (Figure

4).

[0090] As explained above, the second M2 synchronization message is, in some modalities, a pulse pattern incorporated in the received speed signal (Figure 4). In other words, in some embodiments, the control circuitry 21 is configured to receive the second synchronization message M2 at input 23. For example, the first synchronization message M1 is an incoming synchronization pattern that indicates that a synchronization The actual time will occur within a predefined time and the second synchronization message M2 is a synchronization pattern that indicates the timing of the internal clock 16 of the first control unit 10.

[0091] Alternatively, the second M2 synchronization message is another message, for example, a message transmitted by the communication bus. Thus, in some modalities, the set of control circuits 21 is configured

Petition 870190040802, of 30/04/2019, p. 28/43

21/25 to receive the second M2 synchronization message on the communication bus interface 25, which then serves as an input. For example, the first synchronization message M1 is a synchronization pattern and the second synchronization message M2 indicates a relationship between the synchronization pattern and the internal clock 16 of the first control unit 10.

[0092] The control circuitry 21 is then configured to determine a timing of an internal clock 16 of the first control unit 10, based on the first synchronization message M1 and the second synchronization message M2.

[0093] According to some modalities, the set of control circuits 21 is configured to adjust the timing of the internal clock 26 of the second control unit 20 based on the determined timing. In other words, the second control unit adapts its internal clock to match the first control unit, using these synchronization messages. This is usually done gradually so that intermittent errors are mitigated.

[0094] According to some modalities, the control circuitry 21 is configured to detect a second M2 synchronization message to be incorporated into the combined synchronization and arrival speed signal.

[0095] The description also refers to a corresponding method for communicating synchronization and speed information to a second control unit 20 of vehicle 1 (Figure 1). The method will now be explained with reference to the flowchart illustrated in Figure 11 and the illustrations in the other figures. The method can (at least partially) be implemented as program code, P, stored in memory 12 in the first control unit 10. The method can be executed at any time when vehicle 1 is operated.

[0096] The method comprises receiving S1, from a speed sensor 30, a speed signal comprising a pulse train with a frequency corresponding to the speed of an object rotating in vehicle 1. For example, a signal representing the speed of a cog on the motor shaft 4 (Figure 2) is received at input 13 (Figure 8).

Petition 870190040802, of 30/04/2019, p. 29/43

22/25 [0097] Upon receiving the signal, the first control unit analyzes the signal and then modifies the signal to also understand synchronization information in the form of a first M1 synchronization message. In other words, the method further comprises generating S3 a combined speed and synchronization signal by incorporating a first M1 synchronization message into the received speed signal.

[0098] The first control unit also creates other information necessary to interpret the first M1 synchronization message. Thus, the method further comprises generating S4 a second synchronization message M2, wherein the first synchronization message M1 and the second synchronization message M2 together indicate a timing of the internal clock 16.

[0099] The synchronization messages are then sent to the second control unit, at least partially as part of the combined synchronization and speed signal. In other words, the method further comprises transmitting S5 the combined speed and synchronization signal and the second M2 synchronization message to the second control unit.

[0100] In some modalities, the first M1 synchronization message is a predetermined pulse sequence incorporated in the combined synchronization and speed signal.

[0101] In some cases, the first control unit does not start transmitting synchronization messages until the control unit has learned what the tooth wheel looks like and finding the position on the wheel. Thus, in some modalities, the method comprises interpreting S2 the received speed signal. Then, generation S3, S4 and / or transmission S5 is performed in response to the interpretation of S2.

[0102] As has been explained several times, both synchronization messages can be incorporated into the combined synchronization and speed signal. In other words, in some embodiments, the second M2 synchronization message is also incorporated into the combined synchronization and speed signal. In some

Petition 870190040802, of 30/04/2019, p. 30/43

23/25 modalities, the first M1 synchronization message is an arrival synchronization pattern that indicates that a real synchronization will occur within a predefined time and the second M2 synchronization message is a real synchronization pattern that indicates the internal clock timing 16.

[0103] Alternatively, the second synchronization message can be transmitted in another way. For example, the second synchronization message M2 'is a message transmitted on a communication bus of vehicle 1. In some embodiments, the first synchronization message M1 is a synchronization pattern and the second synchronization message M2' indicates a relationship between the internal clock and the synchronization pattern.

[0104] Figure 12 illustrates a corresponding method, for use in a second control unit 20 of a vehicle 1, for receiving synchronization and speed information from a first control unit 10 of the vehicle. The method can (at least partially) be implemented as program code, P, stored in memory 22 in the second control unit 20. The method can be executed at any time when vehicle 1 is operated.

[0105] The method in the second control unit begins when a combined speed and synchronization signal comprising a pulse train with a frequency corresponding to the speed of an object rotating in vehicle 1 is received at an input. In other words, the method comprises receiving S11, from the first control unit 10, a combined synchronization and speed signal comprising a pulse train with a frequency corresponding to the speed of an object in rotation in the vehicle 1.

[0106] The second control unit then begins to scan the first M1 synchronization message. The second control unit is, for example, pre-programmed with information defining a synchronization pattern to be scanned. The second control unit can also be pre-programmed with information that defines where the synchronization pattern will occur in the signal (for example, in a long pulse). In other words, the method further comprises detecting S12 a first M1 synchronization message, incorporated in the combined synchronization signal and

Petition 870190040802, of 30/04/2019, p. 31/43

24/25 speed received. In some embodiments, detection S12 comprises detecting a predetermined pulse sequence in the combined synchronization and arrival speed signal. In some embodiments, detection S12 comprises ignoring the pulse sequences having a frequency above a predefined threshold value. [0107] The method further comprises S13 receiving a second M2 synchronization message from the first control unit. In some embodiments, receiving S13 the second synchronization message M2 comprises detecting a synchronization pattern incorporated in the combined synchronization and speed signal. In some embodiments, the first synchronization message M1 is an incoming synchronization message and the second synchronization message M2 is a synchronization pattern that indicates a timing of the internal clock 16 of the first control unit 10.

[0108] In some embodiments, receiving S13 the second M2 synchronization message comprises receiving the second M2 synchronization message 'on a communication bus. In some embodiments, the first synchronization message M1 is a synchronization pattern and the second synchronization message M2 'indicates a relationship between the synchronization pattern and a timing of the internal clock 16 of the first control unit 10.

[0109] The second control unit can now determine the timing of the internal clock of the first control unit 10 and, consequently, also the drift of its own internal clock in relation to it. In other words, the method further comprises determining S14 a timing of an internal clock 16 of the first control unit 10, based on the first synchronization message M1 and the second synchronization message M2.

[0110] In some embodiments, the method comprises setting S15 to a timing of an internal clock 26 of the second control unit 20 based on the determined timing.

[0111] This description is not limited to the preferential modalities described above. Various alternatives, modifications and equivalents can be used. Therefore, the above modalities should not be considered as limiting the

Petition 870190040802, of 30/04/2019, p. 32/43

25/25 scope of the description, which is defined by the appended claims.

Claims (15)

1. First control unit (10) for use in a vehicle (1), characterized by the fact that it comprises: - an internal clock (16), - an input (13) configured to receive, from a speed sensor (30), a speed signal comprising a pulse train corresponding to the speed of an object in rotation in the vehicle (1), - one or more outputs (14, 15) configured to allow transmission to a second control unit (20), - set of control circuits (11) configured for: • generate a combined synchronization and speed signal incorporating a first synchronization message (M1) in an arrival speed signal received at the entrance (13), • generate a second synchronization message (M2), in which the first synchronization message (M1) and the second synchronization message (M2) together indicate an internal clock timing (16), and • transmit the first synchronization message (M1) and the second synchronization message (M2) to the second control unit ( 20) at one or more exits (14, 15). 2. First control unit (10), according to claim 1, characterized by the fact that the one or more outputs (14, 15) comprise a single wire output port (14), and in which the set of Control circuits (11) are configured to transmit the combined speed and synchronization signal on the single wire output port (14). First control unit (10) according to either of claims 1 or 2, characterized in that the one or more outputs (14, 15) comprise a communication bus interface (15) and in which the control circuitry (11) is configured to transmit the second synchronization message (M2) on the communication bus interface (15). Petition 870190040802, of 30/04/2019, p. 34/43 2/4 4. First control unit (10) according to either of claims 1 or 2, characterized in that the control circuitry (11) is configured to incorporate both the first synchronization message (M1) and the second synchronization message (M2) on the combined speed and synchronization signal. 5. First control unit (10), according to claim 4, characterized by the fact that the first synchronization message (M1) is an arrival synchronization pattern that indicates that a real synchronization will occur within a predefined time and wherein the second synchronization message (M2) is a synchronization pattern that indicates the timing of the internal clock (16). 6. First control unit (10) according to any one of claims 1 to 5, characterized in that the rotating object is a gear wheel and the speed sensor (30) is a gear wheel sensor. 7. Second control unit (20) for use in a vehicle (1), characterized by the fact that it comprises: - an internal clock (26), - one or more inputs (23, 25) configured to receive, from a first control unit (10), a combined synchronization and speed signal comprising a pulse train with a frequency corresponding to the speed of a rotating object in the vehicle (1), and - set of control circuits (21) configured for: • detect a first synchronization message (M1), incorporated in a combined synchronization and arrival speed signal received at one or more entries (23, 25), • receive a second synchronization message (M2) from the first transmission unit control (10), and • determining an internal clock timing (16) of the first control unit (10), based on the first synchronization message (M1) and the second synchronization message (M2). Petition 870190040802, of 30/04/2019, p. 35/43 3/4 8. Second control unit (20) according to claim 7, characterized by the fact that the control circuitry (21) is configured to set a timing of an internal clock (26) of the second control unit (26). 20) based on the determined timing. Second control unit (20) according to either of claims 7 or 8, characterized in that the control circuitry (21) is configured to detect a predetermined pulse sequence in the combined synchronization signal and arrival speed. 10. Power train (2), characterized in that it comprises the first control unit as defined in any of claims 1 to 6 and the second control unit (20) as defined in any of claims 7 to 9. 11. Vehicle (1), characterized by the fact that it comprises the power train (2) as defined in claim 10. 12. Method, for use in a first control unit (10) in a vehicle (1), to communicate synchronization and speed information to a second control unit (20) in the vehicle (1), in which the first control unit control (10) has an internal clock (16), characterized by the fact that it comprises: - receive (S1), from a speed sensor (30), a speed signal comprising a pulse train with a frequency corresponding to the speed of an object rotating in the vehicle (1), - generate (S3) a combined synchronization and speed signal incorporating a first synchronization message (M1) in the received speed signal, - generating (S4) a second synchronization message (M2), wherein the first synchronization message (M1) and the second synchronization message (M2) together indicate an internal clock timing (16), and - transmitting (S5) the combined synchronization and speed signal and the second synchronization message (M2) to the second control unit (20). 13. Method, for use in a second control unit (20) of a Petition 870190040802, of 30/04/2019, p. 36/43 ΑΙΑ vehicle (1), to receive synchronization and speed information from a first vehicle control unit (10), characterized by the fact that it comprises: - receiving (S11), from the first control unit (10), a combined synchronization and speed signal comprising a pulse train with a frequency corresponding to the speed of an object rotating in the vehicle (1), - detecting (S12) a first synchronization message (M1), incorporated in the combined synchronization and speed signal received, - receiving (S13) a second synchronization message (M2) from the first control unit, - determining (S14) a timing of an internal clock (16) of the first control unit (10), based on the first synchronization message (M1) and the second synchronization message (M2). 14. Computer program, characterized by the fact that it comprises instructions that, when the program is executed by a computer, cause the computer to execute the method as defined in any of claims 12 or 13. 15. Computer-readable medium, characterized by the fact that it comprises instructions that, when executed by a computer, cause the computer to execute the method as defined in any of claims 12 or 13.