Motor and controller authentication system

Abstract

Embodiments of the present disclosure relate to motor / controller authentication systems. Described herein is an electric motor drive system including at least one power phase line, an external controller configured to generate a drive signal and provide the drive signal to the at least one power phase line, and electric motor electronics. The electric motor electronics include at least one switch coupled between the at least one power phase line and at least one motor terminal, and an internal controller configured to cooperate with the external controller to perform an authentication process between the external controller and the internal controller. The external controller is further configured to cause the at least one switch to electrically couple the at least one power phase line to the at least one motor terminal in response to a success of the authentication process.

Description

Technical Field

[0001] This disclosure relates to the field of electric motor certification and can be used in vehicle applications, but may also be used in other applications. Background Technology

[0002] Vehicles and other products are increasingly reliant on electric motors as a torque source during operation. For example, an electric motor can provide rotational torque to the wheels of a vehicle, and / or to other components such as door locking mechanisms, door opening mechanisms, steering assist mechanisms, window opening mechanisms, sunroof opening mechanisms, etc. Typically, such an electric motor is paired with an external controller that provides control signals to the motor, such as a torque request transmitted from the vehicle's accelerator pedal to the motor.

[0003] When such an electric motor or its external controller fails, it is desirable for vehicle manufacturers to have a means to ensure that the faulty component is replaced with a suitable replacement part (rather than an unsuitable or counterfeit part) to ensure the correct and safe operation of the vehicle. It is also desirable to prevent theft of vehicles that use electric motors as a torque source, for example, preventing thieves from connecting the controller to the electric motor under their control, which provides rotational torque to the vehicle's wheels, thereby gaining control over and driving the vehicle from these motors; or, as another example, preventing thieves from connecting the controller to the electric motor under their control, which provides rotational torque to the motor of the vehicle's gate locking mechanism, thereby gaining control over and unlocking the gate from that motor.

[0004] Therefore, a safety certification system is needed between motors and their external controllers to help ensure that the right motor is used with the right external controller. Summary of the Invention

[0005] This document discloses an electric motor drive system including at least one power phase line and an external controller. The external controller may include: a DC power source; a microcontroller; and an inverter configured to convert the DC power into a drive signal under the control of the microcontroller and provide the drive signal to the at least one power phase line. The external controller includes a motor unit. The motor unit includes: a motor; a microcontroller configured to communicate with the microcontroller of the external controller; and at least one switch coupled between the at least one power phase line and the motor, the at least one switch being controlled by the microcontroller. The microcontroller of the external controller and the microcontroller of the motor unit are configured to perform an authentication process between them. The microcontroller of the external controller is configured to, in response to the success of the authentication process, instruct the microcontroller of the motor unit to cause the at least one switch to electrically couple the at least one power phase line to the motor.

[0006] At least one switch may be a transistor having a first conductive terminal coupled to the at least one power phase line, a second conductive terminal coupled to the motor, and a control terminal coupled to be controlled by a microcontroller of the motor unit.

[0007] The motor unit may also include a gate driver configured to generate a gate drive signal for turning the transistor on or off under the control of the microcontroller of the motor unit.

[0008] The gate driver may include: a light-emitting diode (LED) that generates light in response to a microcontroller of a motor unit; and a photovoltaic cell located near the LED that generates a gate drive signal in response to the light generated by the LED.

[0009] The microcontrollers of the external controller and the motor unit can be connected via at least one wire other than the at least one power phase line to provide communication between them for performing the authentication process.

[0010] The microcontroller of the external controller can be configured to transmit communication to the microcontroller of the motor unit by modulating the voltage on the at least one power phase line.

[0011] The motor unit may also include an authentication circuit configured to cooperate with the microcontroller of the motor unit when the authentication process is performed.

[0012] The at least one power phase line may include a first, second, and third power phase line. The inverter can convert DC power into three-phase power, wherein the first phase is output on the first power phase line, the second phase is output on the second power phase line, and the third phase is output on the third power phase line. At least one switch may be a first switch coupled between the first power phase line and the first phase winding of the motor, a second switch coupled between the second power phase line and the second phase winding of the motor, and a third switch coupled between the third power phase line and the third phase winding of the motor. In response to successful instruction and authentication by the microcontroller of the external controller, the microcontroller of the motor unit may cause the first switch to couple the first power phase line to the first phase winding, cause the second switch to couple the second power phase line to the second phase winding, and cause the third switch to couple the third power phase line to the third phase winding.

[0013] The first switch can be a first n-channel transistor having a drain coupled to a first power phase line, a source coupled to a first phase winding of the motor, and a gate coupled to be controlled by a microcontroller of the motor unit. The second switch can be a second n-channel transistor having a drain coupled to a second power phase line, a source coupled to a second phase winding of the motor, and a gate coupled to be controlled by a microcontroller of the motor unit. The third switch can be a third n-channel transistor having a drain coupled to a third power phase line, a source coupled to a third phase winding of the motor, and a gate coupled to be controlled by a microcontroller of the motor unit.

[0014] The motor unit also includes a gate driver configured to generate first, second, and third gate drive signals for turning the first, second, and third n-channel transistors on or off under the control of the microcontroller of the motor unit.

[0015] The gate driver may include: a first light-emitting diode (LED) that generates light in response to the microcontroller; a first photovoltaic cell positioned adjacent to the first LED, the first photovoltaic cell generating the first gate drive signal in response to the light generated by the first LED; a second LED that generates light in response to the microcontroller; a second photovoltaic cell positioned adjacent to the second LED, the second photovoltaic cell generating the second gate drive signal in response to the light generated by the second LED; and a third LED that generates light in response to the microcontroller; and a third photovoltaic cell positioned adjacent to the third LED, the third photovoltaic cell generating the third gate drive signal in response to the light generated by the third LED.

[0016] This document discloses an electric motor drive system including first, second, and third power phase lines and an external controller. The external controller includes: a DC power source; a microcontroller; and a three-phase inverter configured to convert the DC power into three-phase power and provide the three-phase power across the first, second, and third power phase lines under the control of the microcontroller. An electric motor unit includes: a three-phase electric motor; communication circuitry coupled to the first, second, and third power phase lines; a microcontroller configured to communicate with the external controller; and first, second, and third switches coupled between the first, second, and third power phase lines and the three-phase electric motor, the first, second, and third switches being controlled by the microcontroller.

[0017] The microcontrollers of the external controller and the motor unit are configured to perform an authentication process between them by communicating on the first, second, and third power phase lines. Communication on the first, second, and third power phase lines is performed as follows: the microcontroller of the external controller modulates the voltage on at least one of the first, second, and third power phase lines using a three-phase inverter; and the communication circuit of the motor unit modulates the voltage on at least one of the first, second, and third power phase lines using a communication circuit while keeping the first, second, and third switches closed.

[0018] The microcontroller of the motor unit is configured to, in response to the success of the authentication process and instructions from the microcontroller of the external controller, cause the first, second, and third switches to electrically couple the first, second, and third power phases to the three-phase motor.

[0019] The three-phase inverter may include: a first high-side transistor coupled between a first node and a DC power supply; a first low-side transistor coupled between the first node and ground; a second high-side transistor coupled between a second node and the DC power supply; a second low-side transistor coupled between the second node and ground; a third high-side transistor coupled between a third node and the DC power supply; and a third low-side transistor coupled between the third node and ground. The first node is coupled to a first power phase line. The second node may be coupled to a second power phase line, and the third node is coupled to a third power phase line.

[0020] The motor unit may include a power supply device configured to generate digital power voltages from the first, second, and third power phase lines.

[0021] The communication transmission circuit of the motor unit may include: a first resistor coupled between the first and second power phase lines; a first LED coupled between a transmit signal generated by the microcontroller of the motor unit and a digital power supply voltage; a first phototransistor coupled between the second and third power phase lines, the first phototransistor being close to the first LED such that the first phototransistor is turned on when the first LED emits light; a second LED coupled between the first and second power phase lines; and a second phototransistor having a first conductive terminal coupled to the digital power supply voltage and a receive signal input of the microcontroller of the motor unit, and a second conductive terminal coupled to ground, the second phototransistor being close to the second LED such that the second phototransistor is turned on when the second LED emits light.

[0022] The microcontroller of the external controller can modulate the voltage on the second power phase line by keeping the first high-side transistor and the third low-side transistor on, modulating the second low-side transistor, and keeping the other transistors of the three-phase inverter off.

[0023] The microcontroller of the motor unit can modulate the voltage on the second phase line in the following way: when the microcontroller of the external controller keeps the first high-side transistor and the third low-side transistor on and keeps the other transistors of the three-phase inverter off, the microcontroller of the motor unit modulates the transmitted signal.

[0024] This document also discloses an electric motor drive system. The electric motor drive system includes: at least one power phase line; an external controller configured to generate a drive signal and provide the drive signal to the at least one power phase line; and motor electronics. The motor electronics include: at least one switch coupled between the at least one power phase line and at least one motor terminal; and an internal controller configured to cooperate with the external controller to perform an authentication process therebetween. The external controller is further configured to cause the at least one switch to electrically couple the at least one power phase line to the at least one motor terminal in response to a successful authentication process.

[0025] The internal controller may include: a gate driver configured to generate a gate drive signal for turning the switch on or off; and a microcontroller configured to cooperate with the external controller to perform the authentication process and to cause the gate driver to generate the gate drive signal in response to the success of the authentication process and instructions from the external controller.

[0026] The gate driver may include: a light-emitting diode (LED) that generates light in response to a microcontroller; and a photovoltaic cell located near the LED that generates a gate drive signal in response to the light generated by the LED.

[0027] The internal controller and the external controller can be connected via at least one wire different from at least one power phase line to provide communication between them for performing the authentication process.

[0028] The internal controller can be configured to send communications to the external controller by modulating the voltage on at least one power phase line. The external controller can be configured to send communications to the internal controller by modulating the voltage on at least one power phase line.

[0029] At least one motor terminal may include a first, second, and third motor terminal. The at least one power phase line may include a first, second, and third power phase line. The at least one switch may include a first switch coupled between the first power phase line and the first motor terminal, a second switch coupled between the second power phase line and the second motor terminal, and a third switch coupled between the third power phase line and the third motor terminal. In response to a successful authentication process, an external controller may cause the first switch to couple the first power phase line to the first motor terminal. In response to a successful authentication process, an external controller may cause the second switch to couple the second power phase line to the second motor terminal. In response to a successful authentication process, an external controller may cause the third switch to couple the third power phase line to the third motor terminal.

[0030] This document also discloses a method for operating an electric motor using an external controller. The method may include performing an authentication process between the external controller and the electric motor; generating a motor phase power signal in response to the success of the authentication process; and applying the motor phase power signal to the external motor in response to the success of the authentication process.

[0031] In response to the successful certification process, the motor phase power signal can be applied to an external motor by using a switch that is closed-coupled between the motor phase power signal and the motor. Attached Figure Description

[0032] Figure 1 This is a block diagram of a first motor drive system with authentication functionality between the electric motor and an external controller that drives the motor.

[0033] Figure 2 This is a block diagram of a second motor drive system with authentication functionality between the electric motor and an external controller that drives the electric motor.

[0034] Figure 3This is a block diagram of a third motor drive system with authentication functionality between the electric motor and an external controller that drives the electric motor.

[0035] Figure 4 This is a block diagram of a fourth motor drive system with authentication functionality between the electric motor and an external controller that drives the motor. Detailed Implementation

[0036] The following disclosure enables those skilled in the art to make and use the subject matter disclosed herein. The general principles described herein can be applied to embodiments and applications other than those detailed above, without departing from the spirit and scope of this disclosure. This disclosure is not intended to be limited to the embodiments shown, but is consistent with the widest scope of the principles and features disclosed or suggested herein.

[0037] Now refer to Figure 1 An electric motor drive system 10 is described, comprising an electric motor unit 30 and an external controller 20 for the electric motor unit 30. The electric motor unit 30 may be positioned at the wheels of a vehicle (e.g., a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle, etc.) to provide rotational torque to the wheels, thereby causing acceleration or speed maintenance of the vehicle, and the external controller 20 may be positioned at the chassis of the vehicle, with the electrical connection between the electric motor unit and the external controller formed by wires or other conductors.

[0038] The external controller 20 includes a power supply circuit 21 that generates an electrical power signal PWR from electrical power supplied by a battery voltage (not shown). The electrical power signal PWR is intended to be used by the motor unit 30 to generate rotational torque. The power supply circuit 21 also generates a digital power signal Vdd to power the microcontroller 22 and data interface 23 within the external controller 20.

[0039] The motor unit 30 includes a motor housing that carries a motor 37 and motor electronics 31 for powering and controlling the motor 37 based on a power signal PWR and encrypted communication received from a data interface 23 of an external controller 20. The motor 37 may be a three-phase brushless DC motor.

[0040] The motor electronics 31 includes a power management circuit 32, which includes a DC / DC converter that converts the power signal PWR into a bus voltage. This bus voltage is then converted by an inverter in the power stage 36 to generate a three-phase drive signal for driving the motor 37. The motor electronics 31 also includes a data interface 33 for interfacing with a data interface 23 of an external controller 20. A control unit 34 within the motor electronics 31 includes a microcontroller for communicating with the external controller 20 via the data interface 33 and for generating one or more control signals Ctrl for the power stage 36 based on these communications. The motor 37 generates a feedback signal Fbk for use by the control unit 34, for example, to determine the motor speed.

[0041] The communication sent from the external controller 20 to the motor unit 30 is encrypted by the external controller 20 and decrypted by the control unit 34 of the motor electronics 31, and the communication sent from the motor unit 30 to the external controller 20 is encrypted by the control unit 34 of the motor electronics 31 and decrypted by the microcontroller 22 of the external controller 20.

[0042] For security purposes, when the vehicle equipped with the electric motor drive system 10 is started (e.g., a driver with a key chain paired with the vehicle enters the vehicle and instructs it to start), the microcontroller 22 of the external controller 20 starts up via a dedicated communication line and establishes secure encrypted communication with the control unit 34 within the electric motor housing 30, which has a data interface 33 with the control unit 34. Once secure encrypted communication is established between the microcontroller 22 and the control unit 34, the microcontroller 22 attempts to authenticate the electric motor 37 by sending an authentication request to the control unit 34. If the authentication request sent by the microcontroller 22 to the control unit 34 is the desired authentication request, and if the control unit 34 returns the desired authentication response, the electric motor 37 is considered authenticated and thus certified as an authorized component. At this point, the external controller 20 can begin controlling the electric motor 37, for example, to make the vehicle drivable.

[0043] Security is provided by the motor drive system 10 in two ways. First, authentication is not performed until secure encrypted communication is established between the controller 20 and the control unit 34. This first step eliminates the possibility that some unauthorized motor units 30 and some unauthorized controllers 20 could communicate with each other, meaning that the motor 37 cannot operate. This authentication adds a second level of security because authentication is not performed unless the authentication request sent by the microcontroller 22 of the external controller 20 to the control unit 34 of the motor unit 30 is the expected authentication request, and unless the control unit 34 returns the expected authentication response to the microcontroller 22.

[0044] See now Figure 2 The next embodiment of the motor drive system 10' is described. Here, the power supply circuit 21' of the external controller 20' includes a regulator circuit 49 that generates a digital power signal Vdd to power the microcontroller 22, the data interface 23, and the control unit 34', data interface 33, and authentication circuit 35 of the motor electronics 31'. The regulator circuit 49 receives an input voltage Vbatt from a battery and provides the input voltage to a three-phase inverter 50 within the power supply circuit 21' (instead of being located within the motor unit 30). The three-phase inverter 50 generates three power phase signals, phase U, phase V, and phase W.

[0045] Here, the motor unit 30' includes a motor housing carrying the motor 37 (here, a three-phase motor) and motor electronics 31', which are used to power and control the motor 37 using three power phase signals U, V, and W, and based on encrypted communication received from the data interface 23 of the external controller 20'. Note that the motor electronics 31' includes switches 46 electrically connected between the power phase signals U, V, and W and the corresponding phase windings of the motor 37. The switches 46 are controlled by control signals from the gate driver 48 (explained below). That is, switch S1 selectively connects the power phase signal U to the corresponding phase winding of the motor 37, switch S2 selectively connects the power phase signal V to the corresponding phase winding of the motor 37, and switch S3 selectively connects the power phase signal W to the corresponding phase winding of the motor 37.

[0046] Still here, the control unit 34' includes a microcontroller 47, which receives and sends encrypted communications via a data interface 33. The microcontroller 37 generates control signals for a gate driver 48 within the control unit 34'. The gate driver 48 generates a control signal Ctrl1 for switch S1 (which causes switch S1 to act as an open circuit or short circuit), a control signal Ctrl2 for switch S2 (which causes switch S2 to act as an open circuit or short circuit), and a control signal Ctrl3 for switch S3 (which causes switch S3 to act as an open circuit or short circuit).

[0047] As will be explained below, if the motor unit 30' and the external controller 20' have successfully performed the authentication process as described above, the microcontroller 47 of the control unit 34' only causes the gate driver 48 to generate control signals Ctrl1, Ctrl2, Ctrl3, which cause switches S1, S2 and S3 to act as short circuits in response to encrypted communication received via data interface 33 to connect the power phase signal phases U, V and W to the phase windings of the motor 37.

[0048] For security purposes, when the vehicle equipped with the electric motor drive system 10' is started (e.g., a driver with a key chain paired with the vehicle enters the vehicle and instructs it to start), the microcontroller 22 of the external controller 20' starts up via its data interface 33 on a dedicated communication line and establishes secure encrypted communication with the microcontroller 47 of the control unit 34' within the electric motor housing 30'. Once secure encrypted communication is established between the microcontroller 22 and the microcontroller 47 of the control unit 34', the microcontroller 22 attempts to authenticate the electric motor 37 by sending an authentication request to the microcontroller 47. If the authentication request sent by the microcontroller 22 to the microcontroller 47 is the expected authentication request, and if the microcontroller 47 returns the expected authentication response, the electric motor 37 is considered authenticated and thus authenticated as an authorized component.

[0049] Upon successful authentication, the microcontroller 22 of the external controller 20' sends a switch enable command to the microcontroller 47 of the control unit 34' using a secure, encrypted communication channel established via a dedicated communication line. The microcontroller 47 then causes the gate driver 48 to generate control signals Ctrl1, Ctrl2, and Ctrl3 to close switches S1, S2, and S3 (e.g., as a short circuit).

[0050] Subsequently, microcontroller 22 begins polling microcontroller 47 on an encrypted communication channel using requests for the states of switches S1, S2, and S3. Once microcontroller 22 receives a response from microcontroller 47 via the encrypted communication channel indicating that switches S1, S3, and S3 are closed, allowing power phase signals U, V, and W to be supplied to motor 37, microcontroller 22 begins operating inverter 50 and motor 37 to enable the user to drive the vehicle. If microcontroller 22 does not respond to its polling response received from microcontroller 47 via the encrypted communication channel after a given time period (e.g., microcontroller 47 times out), microcontroller 22 disables inverter 50 and may report this to another component within the vehicle.

[0051] When the vehicle is deactivated (e.g., a driver with a keychain paired with the vehicle leaves the vehicle and instructs it to be deactivated), microcontroller 22 deactivates inverter 50 to stop motor 37. Once motor 37 has stopped, microcontroller 22 sends a command via the encrypted communication channel to disable switches S1, S2, and S3, and closes the encrypted communication channel. Upon vehicle reactivation, as described above, the encrypted communication channel is re-established and the authentication process is re-executed. Therefore, an encrypted communication channel must be established and the authentication process must be successfully executed each time the motor is started.

[0052] The motor electronics 31' are depicted as including an authentication circuit 35 that is coupled to a microcontroller 47 of the control unit 34'. This authentication circuit 35 is a discrete, dedicated hardware component that performs encryption / decryption and authentication at the aforementioned motor drive system 10'. For example, the authentication circuit 50 could be an STSAFE-A110 device manufactured and sold by STMicroelectronics.

[0053] The authentication circuit 35 is optional, and alternatively, the encryption / decryption and authentication at the aforementioned motor drive system 10' can be performed by the microcontroller 47 using a cryptographic library, such as the X-CUBE-CRYPTOLIB library manufactured and sold by STMicroelectronics.

[0054] The motor drive system 10' provides security in two ways. First, authentication is not performed until secure encrypted communication is established between the controller 20' and the control unit 34', because unauthorized parts may be unable to establish secure encrypted communication (e.g., due to a lack of a desired encryption protocol, etc.). This first step eliminates the possibility that some unauthorized motor units 30' and some unauthorized controllers 20' can communicate with each other, meaning that the motor 37 cannot operate. This authentication adds a second level of security because authentication is not performed unless the authentication request sent from the microcontroller 22 of the external controller 20' to the control unit 34' of the motor unit 30' is the expected authentication request, and unless the control unit 34' returns the expected authentication response to the microcontroller 22.

[0055] Now for reference Figure 3 A more detailed version 10" describes the motor drive system 10'. Specifically, here, switch 46' is an n-channel transistor. Specifically: switch S1 is an n-channel transistor whose drain is connected to receive the power phase signal U, its source is connected to the first phase winding of the motor 37, and its gate is connected to the first output of gate driver 48'; switch S2 is an n-channel transistor whose drain is connected to receive the power phase signal V, its source is connected to the second phase winding of the motor 37, and its gate is connected to the second output of gate driver 48'; switch S3 is an n... The channel transistor has its drain connected to receive the power phase signal W, its source connected to the third phase winding of the motor 37, and its gate connected to the third output of the gate driver 48'. Furthermore, the gate driver 48' is controlled by the microcontroller 47 such that switches S1, S2, and S3 are turned on during the positive and negative portions of their respective power phase signals U, V, and W when on. When off, the body diodes of switches S1, S2, and S3 can only conduct from the source to the drain, but no current flows because current must first be supplied from the inverter 50'.

[0056] The gate driver 48' of the control unit 34" uses photoelectric actuation to generate control signals Ctrl1, Ctrl2, and Ctrl3. Specifically, the gate driver 48' includes: a first LED LED1 and a photovoltaic cell PV1 pair, the cathode of LED1 being coupled to a control signal PA1 from the microcontroller 47 via a resistor R1, and the anode of LED1 being coupled to a digital power signal Vdd; the photovoltaic cell PV1 generates a voltage control signal Ctrl1 for the source 1 of switch S1 when LED1 is activated, causing switch S1 to turn on when LED1 is activated; a second LED LED2 and a photovoltaic cell PV2 pair, the cathode of LED2 being coupled to a control signal PA2 from the microcontroller 47 via a resistor R2, and the anode of LED2 being coupled to the digital power signal Vdd; the photovoltaic cell PV2 generates a voltage control signal Ctr2 for the source 2 of switch S2 when LED2 is activated, causing switch S2 to turn on when LED2 is activated; and a third LED... LED3 and photovoltaic cell PV3 are paired, wherein the cathode of LED3 is coupled to the control signal PA3 from microcontroller 47 through resistor R3, and its anode is coupled to the digital power signal Vdd. When LED3 is activated, photovoltaic cell PV3 generates a control voltage signal Ctrl3 for source 3 of switch S3, so that switch S3 is turned on when LED3 is activated.

[0057] This place and Figure 2 Another difference in the motor drive system 10' is that details of the three-phase inverter 50' are shown here. Specifically, the inverter 50' includes: an N-channel transistor T1, whose drain is connected to the battery voltage Vbatt, whose source is connected to node U, and whose gate is connected to the U-phase high-side control signal Uh; an N-channel transistor T2, whose drain is connected to node U, whose source is connected to ground, and whose gate is connected to the U-phase low-side control signal U1; an n-channel transistor T3, whose drain is connected to the battery voltage Vbatt, whose source is connected to node V, and whose gate is connected to the V-phase high-side control signal Vh; an n-channel transistor T4, whose drain is connected to node V, whose source is connected to ground, and whose gate is connected to the V-phase low-side control signal V1; an N-channel transistor T5, whose drain is connected to the battery voltage Vbatt, whose source is connected to node W, and whose gate is connected to the W-phase high-side control signal Vh; and an n-channel transistor T6, whose drain is connected to node W, whose source is connected to ground, and whose gate is connected to the W-phase low-side control signal W1.

[0058] The microcontroller 22 of the external controller 20' is responsible for generating control signals Uh, Ul, Vh, Vl, Wh and Wl to control the transistors T1-T6 of the inverter 50' in a desired manner, thereby generating three power phase signals, phase U, phase V and phase W.

[0059] The motor drive system 10" operates in the same manner as the motor drive system 10', for establishing encrypted communication channels and performing authentication, except that the microcontroller 47 asserts control signals PA1, PA2, and PA3 to cause assertions of control signals Ctrl1, Ctrl2, and Ctrl3 for switches S1, S2, and S3. This, in turn, causes LEDs 1, LED2, and LED3 to turn on, which in turn causes PV1 to assert Ctrl1, PV2 to assert Ctrl2, and PV3 to assert Ctrl3. Note that the floating control voltages Ctrl1, Ctrl2, and Ctrl3 relative to the source voltages Source1, Source2, and Source3 of switches S1, S2, and S3 ensure that these switches are turned on when Ctrl1, Ctrl2, and Ctrl3 are asserted.

[0060] Now for reference Figure 4 Another embodiment of the motor unit 30”' is described, for example, it can be used with Figure 2 -3 is used together with the external controller 20'. Here, the motor unit 30"' also includes a rectifier 60, a power supply 61, and a communication circuit 62. As will be explained below, the communication circuit 62 enables communication with the external controller without using one or more wires for encrypted communication, but instead utilizes wires carrying power phase signals U, V, and W for communication and power reception.

[0061] The rectifier 60 includes: a first diode D01, whose anode is connected to the power phase signal U at node N1 and whose cathode is connected to node N4; a second diode D02, whose anode is grounded and whose cathode is connected to node N1; a third diode D03, whose anode is connected to the power phase signal V at node N2 and whose cathode is connected to node N4; a fourth diode D04, whose anode is grounded and whose cathode is connected to node N2; a fifth diode D05, whose anode is connected to the power phase signal W at node N3 and whose cathode is connected to node N4; and a sixth diode D06, whose anode is connected to ground and whose cathode is connected to node N3.

[0062] Power supply 61 includes: a Zener diode D07, whose anode is grounded and whose cathode is connected to generate a regulated digital power signal Vdd; a capacitor C2 connected between the digital power signal Vdd and ground; a resistor R02 having a first terminal connected to the cathode of diode D07 and a second terminal connected to the first terminal of capacitor C1; a capacitor C1, whose first terminal is connected to the second terminal of resistor R02, and whose second terminal is grounded; and a resistor R01 connected between the first terminal of capacitor C1 and node N4.

[0063] Switch 46' is an n-channel transistor. Specifically: switch S1 is an n-channel transistor whose drain is connected to receive the power phase signal U, its source is connected to the first phase winding of the motor 37, and its gate is connected to receive the control signal U_EN from the MCU / gate driver 34”'; switch S2 is an n-channel transistor whose drain is connected to receive the power phase signal V, its source is connected to the second phase winding of the motor 37, and its gate is connected to receive the control signal V_EN from the MCU / gate driver 34”'; switch S3 is an n-channel transistor whose drain is connected to receive the power phase signal W, its source is connected to the third phase winding of the motor 37, and its gate is connected to receive the control signal W_EN from the MCU / gate driver 34”'.

[0064] Communication circuit 62 includes: a resistor R06 connected between nodes N1 and N2; a first phototransistor PT1 connected between nodes N2 and N3; a first LED LED01 having an anode connected to a digital power signal Vdd via resistor R07 and a cathode connected to an MCU / gate driver 34"', the MCU / gate driver 34"' being activated by a transmit signal MCU_Tx from the first LED LED01; a second phototransistor PT2 having a first conductive terminal connected to the digital power signal Vdd via resistor R05 and a second conductive terminal grounded; and a second LED LED02 having an anode connected to node N1 via resistor R03 and a cathode connected to node N2 via resistor R04. Note that the first conductive terminal of phototransistor PT2 is also connected to the MCU / gate driver 34"'' to provide it with a receive signal MCU_Rx.

[0065] Initially (e.g., when the motor unit 30''' is activated upon entering the vehicle), the inverter (which is located within an external controller, e.g.) Figure 3 The inverter 50' is turned off without switching, and switches S1, S2, and S3 are set to open (acting as open circuits) by the MCU / gate driver 34'''. Then, transistors T1 and T6 of the inverter are turned on by the assertions of control signals Uh and Wl. This causes current to flow from the rectifier 60 into capacitors C1 and C2 of the power supply 61, charging these capacitors and generating the digital power supply voltage Vdd.

[0066] Then, the external controller establishes half-duplex communication by first keeping transistors T1 and T6 of the inverter on, and modulating transistor T4 of the inverter to send data, while keeping the other transistors of the inverter off. This data transmission is because when transistor T4 is on (and transistor T1 is on simultaneously), a current path is established from node N1, through resistor R03, into the anode of LED02, out of the cathode of LED02, and through resistor R04, through transistor T4 to ground. Therefore, when transistor T4 is on, LED02 is on, causing phototransistor PT2 to turn on and pull the received signal MCU_Rx to ground. Thus, by modulating transistor T4 while keeping transistors T1 and T6 on, the external controller can send one bit at a time to the MCU / gate driver 34'''.

[0067] For communication from the motor unit 30''' back to the external controller, the external controller can keep inverter transistors T1 and T6 on and the other inverter transistors off. The MCU / gate driver 34''' can then modulate the transmit signal MCU_Tx. When LED LED01 is on (and transistors T1 and T6 are on simultaneously), a current path is established from node N1, through resistor R06, through phototransistor PT1, through transistor T6 to ground. Therefore, when the transmit signal MCU_Tx is asserted, LED01 is turned on, and phototransistor PT1 is turned on in turn, pulling the voltage at node N2 (and thus the voltage at node V of the inverter) down to zero volts. Therefore, if the external controller's inverter transistors T1 and T6 remain on while the other inverter transistors remain off, the MCU / gate driver 34''' can send one bit at a time to the external controller by modulating the transmit signal MCU_Tx.

[0068] Having described the communication methods between the external controller and the motor unit 30''', the operation of the motor unit 30''' will now be described to provide security. The initial communication from the external controller to the MCU / gate driver 34''' establishes a secure, encrypted communication channel between the external controller and the MCU / gate driver 34'''.

[0069] Once secure encrypted communication is established between the external controller and the MCU / gate driver 34''', the external controller attempts to authenticate the motor 37 by sending an authentication request to the MCU / gate driver 34'''. If the authentication request sent by the external controller to the MCU / gate driver 34''' is the expected authentication request, and if the MCU / gate driver 34''' returns the expected authentication response, the motor 37 is considered authenticated and thus certified as an authorized component.

[0070] Upon successful authentication, the external controller sends a switch enable command to the MCU / gate driver 34''' using a secure, encrypted communication channel established on the conductors carrying the power phase signals, phase U, phase V, and phase W. Subsequently, the external controller begins polling the MCU / gate driver 34''' on the encrypted communication channel with a request for confirmation of the switch enable. After confirming successful reception of the switch enable command, the MCU / gate driver 34''' generates control signals U_En, V_En, and W_En, causing transistors S1, S2, and S3 to close (e.g., act as a short circuit).

[0071] Once the external controller receives a response from the MCU / gate driver 34''' indicating that switches S1, S3, and S3'' are closed via an encrypted communication channel, allowing power phase signals U, V, and W to be supplied to the motor 37', the external controller activates the inverter output to the motor 37', enabling the user to drive the vehicle. If the external controller does not receive a response from the MCU / gate driver 34''' in response to its polling after a given time period (e.g., when the MCU / gate driver 34''' times out), the external controller disables its inverter and may report this to another component within the vehicle.

[0072] When the vehicle is deactivated (e.g., a driver holding a keychain paired with the vehicle leaves the vehicle and instructs it to be deactivated), the external controller deactivates its inverter. This means that the power supply 61 within the motor unit 30''' is no longer able to generate the digital power supply voltage Vdd, resulting in the MCU / gate driver 34''' being turned off, control signals U_En, V_En, and W_En decaying, and switches S1, S2, and S3 opening. Upon vehicle reactivation, as described above, the digital power supply voltage Vdd is first generated, and then, as described above, the encrypted communication channel can be re-established, and the authentication process can be re-executed. Therefore, an encrypted communication channel must be established each time the motor starts, and the authentication process must be successfully executed.

[0073] The motor drive system 10 provides security in two ways. First, authentication is not performed until secure encrypted communication is established between the external controller and the MCU / gate driver 34''', because unauthorized parts may be unable to establish secure encrypted communication (e.g., due to the inability to use the desired encryption protocol, etc.). This first step eliminates the possibility that some unauthorized motor units 30''' and some unauthorized external controllers cannot communicate with each other, meaning that motor 37 cannot be operated. Authentication adds a second level of security because authentication is not performed unless the authentication request sent by the external controller to the MCU / gate driver 34''' is the desired authentication request, and unless the MCU / gate driver 34''' returns the desired authentication response to the external controller.

[0074] The aforementioned motor drive systems 10', 10" and 10''' provide theft protection and prevent the use of counterfeit or unapproved components. Theft protection is provided because only an approved external controller can establish secure communication with the motor units 30', 30" and 30''', successfully perform authentication, and activate switches S1, S2 and S3. Therefore, an unapproved external controller cannot cause the motor to operate (and may not include a suitable inverter to supply power to the motor). This means that a counterfeit external controller will not cause the motor to operate, and therefore, in addition to providing theft protection, the OEM external controller cannot be replaced by a counterfeit external controller for repair. This also means that a counterfeit motor will not be operated by the OEM external controller due to a failed authorization process. Although the invention has been described with respect to a limited number of embodiments, those skilled in the art to which this invention pertains will understand that other embodiments may be conceived without departing from the scope of the invention disclosed herein. Therefore, the scope of this disclosure will be limited only by the appended claims.

Claims

1. An electric motor drive system, comprising: At least one power phase line; An external controller, the external controller comprising: DC power source; The microcontroller of the external controller; and An inverter is configured to convert the DC power into a drive signal under the control of the microcontroller of the external controller, and to provide the drive signal to the at least one power phase line; The motor unit includes: Electric motor; The microcontroller of the motor unit is configured to communicate with the microcontroller of the external controller; and At least one switch is coupled between the at least one power phase line and the motor, and the at least one switch is under the control of the microcontroller of the motor unit; The microcontroller of the external controller and the microcontroller of the motor unit are configured to perform an authentication process between them; and The microcontroller of the external controller is configured to instruct the microcontroller of the motor unit to cause the at least one switch to electrically couple the at least one power phase line to the motor in response to the success of the authentication process.

2. The motor drive system of claim 1, wherein the at least one switch comprises a transistor having a first conductive terminal coupled to the at least one power phase line, a second conductive terminal coupled to the motor, and a control terminal coupled to be controlled by a microcontroller of the motor unit.

3. The motor drive system according to claim 2, wherein the motor unit further includes a gate driver configured to generate a gate drive signal under the control of a microcontroller of the motor unit, the gate drive signal being used to turn the transistor on or off.

4. The electric motor drive system according to claim 3, wherein the gate driver comprises: A light-emitting diode that generates light in response to the microcontroller of the motor unit; A photovoltaic cell is positioned adjacent to the light-emitting diode, the photovoltaic cell generating the gate drive signal in response to the light generated by the light-emitting diode.

5. The electric motor drive system of claim 1, wherein the microcontroller of the external controller and the microcontroller of the motor unit are connected by at least one wire different from the at least one power phase line to provide communication between the external controller and the motor unit for performing the authentication process.

6. The electric motor drive system of claim 1, wherein the microcontroller of the external controller is configured to transmit communication to the microcontroller of the electric motor unit by modulating the voltage on the at least one power phase line; and wherein the microcontroller of the electric motor unit is configured to transmit communication to the microcontroller of the external controller by modulating the voltage on the at least one power phase line.

7. The electric motor drive system of claim 1, wherein the electric motor unit further includes an authentication circuit configured to cooperate with the microcontroller of the electric motor unit when the authentication process is performed.

8. The electric motor drive system according to claim 1, wherein: The at least one power phase line includes a first power phase line, a second power phase line, and a third power phase line; The inverter converts DC power into three-phase power, wherein the first phase is output on the first power phase line, the second phase is output on the second power phase line, and the third phase is output on the third power phase line; The at least one switch includes a first switch coupled between the first power phase line and the first phase winding of the motor, a second switch coupled between the second power phase line and the second phase winding of the motor, and a third switch coupled between the third power phase line and the third phase winding of the motor; as well as In response to the instructions of the microcontroller of the external controller and the success of the authentication process, the microcontroller of the motor unit causes the first switch to couple the first power phase line to the first phase winding, causes the second switch to couple the second power phase line to the second phase winding, and causes the third switch to couple the third power phase line to the third phase winding.

9. The electric motor drive system according to claim 8, wherein: The first switch includes a first n-channel transistor having a drain coupled to the first power phase line, a source coupled to the first phase winding of the motor, and a gate coupled to be controlled by a microcontroller of the motor unit. The second switch includes a second n-channel transistor having a drain coupled to the second power phase line, a source coupled to the second phase winding of the motor, and a gate coupled to be controlled by the microcontroller of the motor unit. as well as The third switch includes a third n-channel transistor having a drain coupled to the third power phase line, a source coupled to the third phase winding of the motor, and a gate coupled to be controlled by the microcontroller of the motor unit.

10. The motor drive system of claim 9, wherein the motor unit further includes a gate driver configured to generate, under the control of the microcontroller of the motor unit, a first gate drive signal, a second gate drive signal, and a third gate drive signal for turning on or off the first n-channel transistor, the second n-channel transistor, and the third n-channel transistor.

11. The electric motor drive system of claim 10, wherein the gate driver comprises: A first light-emitting diode that generates light in response to a microcontroller of the motor unit, and a first photovoltaic cell positioned adjacent to the first light-emitting diode, the first photovoltaic cell generating the first gate drive signal in response to light generated by the first light-emitting diode; A second light-emitting diode, which generates light in response to the microcontroller of the motor unit, and a second photovoltaic cell, which is positioned adjacent to the second light-emitting diode and generates the second gate drive signal in response to the light generated by the second light-emitting diode; as well as A third light-emitting diode, which generates light in response to the microcontroller of the motor unit, and a third photovoltaic cell, which is positioned adjacent to the third light-emitting diode and generates the third gate drive signal in response to the light generated by the third light-emitting diode.

12. An electric motor drive system, comprising: First power phase line, second power phase line and third power phase line; An external controller, the external controller comprising: DC power source; The microcontroller of the external controller; and A three-phase inverter is configured to convert the DC power into three-phase power under the control of the microcontroller of the external controller, and to provide the three-phase power across the first power phase line, the second power phase line, and the third power phase line; The motor unit includes: Three-phase electric motor; A communication circuit is coupled to the first power phase line, the second power phase line, and the third power phase line; The microcontroller of the motor unit is configured to communicate with the microcontroller of the external controller; and The first switch, the second switch, and the third switch are coupled between the first power phase line, the second power phase line, and the third power phase line and the three-phase motor, and the first switch, the second switch, and the third switch are under the control of the microcontroller of the motor unit; The microcontrollers of the external controller and the motor unit are configured to perform an authentication process between the external controller and the motor unit by communicating on the first power phase line, the second power phase line, and the third power phase line, wherein the communication on the first power phase line, the second power phase line, and the third power phase line is performed in the following manner: The microcontroller of the external controller uses the three-phase inverter to modulate the voltage on at least one of the first, second, and third power phase lines; and The communication circuit of the motor unit uses the communication circuit to modulate the voltage on at least one of the first power phase line, the second power phase line, and the third power phase line, while keeping the first switch, the second switch, and the third switch closed; and The microcontroller of the motor unit is configured to, in response to the success of the authentication process and instructions from the microcontroller of the external controller, cause the first switch, the second switch, and the third switch to electrically couple the first power phase line, the second power phase line, and the third power phase line to the three-phase motor.

13. The electric motor drive system according to claim 12, wherein the three-phase inverter comprises: A first high-side transistor is coupled between the first node and the DC power source; The first low-side transistor is coupled between the first node and ground; The second high-side transistor is coupled between the second node and the DC power source; The second low-side transistor is coupled between the second node and ground; The third high-side transistor is coupled between the third node and the DC power source; as well as The third low-side transistor is coupled between the third node and ground; The first node is coupled to the first power phase line, the second node is coupled to the second power phase line, and the third node is coupled to the third power phase line.

14. The electric motor drive system of claim 13, wherein the electric motor unit includes a power supply device configured to generate a digital power voltage from the first power phase line, the second power phase line and the third power phase line.

15. The electric motor drive system according to claim 13, The communication circuit of the motor unit includes: A first resistor is coupled between the first power phase line and the second power phase line; A first light-emitting diode is coupled between a transmit signal generated by the microcontroller of the motor unit and a digital power voltage; A first phototransistor is coupled between the second power phase line and the third power phase line. The first phototransistor is close to the first light-emitting diode, such that the first phototransistor is turned on when the first light-emitting diode emits light. The second light-emitting diode is coupled between the first power phase line and the second power phase line; as well as The second phototransistor has a first conductive terminal coupled to the digital power voltage and the received signal input of the microcontroller of the motor unit, and a second conductive terminal coupled to ground. The second phototransistor is close to the second light-emitting diode such that the second phototransistor is turned on when the second light-emitting diode emits light.

16. The motor drive system of claim 15, wherein the microcontroller of the external controller modulates the voltage on the second power phase line by: keeping the first high-side transistor and the third low-side transistor on, modulating the second low-side transistor, and keeping the other transistors of the three-phase inverter off.

17. The electric motor drive system of claim 16, wherein the microcontroller of the electric motor unit modulates the voltage on the second power phase line in the following manner: When the microcontroller of the external controller keeps the first high-side transistor and the third low-side transistor on and keeps the other transistors of the three-phase inverter off, the microcontroller of the motor unit modulates the transmitted signal.

18. An electric motor drive system, comprising: At least one power phase line; An external controller is configured to generate a drive signal and provide the drive signal to the at least one power phase line; Electric motor electronic devices, the electric motor electronic devices comprising: At least one switch is coupled between the at least one power phase line and at least one motor terminal; as well as An internal controller is configured to cooperate with the external controller to perform an authentication process between the internal controller and the external controller; The external controller is further configured to cause the at least one switch to electrically couple the at least one power phase line to the at least one motor terminal in response to the success of the authentication process, wherein the internal controller is configured to transmit communication to the external controller by modulating the voltage on the at least one power phase line, and wherein the external controller is configured to transmit communication to the internal controller by modulating the voltage on the at least one power phase line.

19. The motor drive system of claim 18, wherein the internal controller includes a gate driver and a microcontroller, the gate driver being configured to generate a gate drive signal for turning the switch on or off, the microcontroller being configured to cooperate with the external controller to perform the authentication process, and to cause the gate driver to generate the gate drive signal in response to success of the authentication process and instructions from the external controller.

20. The electric motor drive system of claim 19, wherein the gate driver comprises: A light-emitting diode that generates light in response to the microcontroller, and a photovoltaic cell positioned adjacent to the light-emitting diode that generates the gate drive signal in response to the light generated by the light-emitting diode.

21. The electric motor drive system of claim 18, wherein the internal controller and the external controller are connected by at least one wire different from the at least one power phase line to provide communication between the internal controller and the external controller for performing the authentication process.

22. The electric motor drive system according to claim 18, wherein: The at least one motor terminal includes a first motor terminal, a second motor terminal, and a third motor terminal; The at least one power phase line includes a first power phase line, a second power phase line, and a third power phase line; The at least one switch includes a first switch coupled between the first power phase line and the first motor terminal, a second switch coupled between the second power phase line and the second motor terminal, and a third switch coupled between the third power phase line and the third motor terminal; In response to the success of the authentication process, the external controller causes the first switch to couple the first power phase line to the first motor terminal. In response to the success of the authentication process, the external controller causes the second switch to couple the second power phase line to the second motor terminal. as well as In response to the success of the authentication process, the external controller causes the third switch to couple the third power phase line to the third motor terminal.

23. A method of operating an electric motor using an external controller, wherein the electric motor includes an internal controller configured to communicate with the external controller, the method comprising: An authentication process is performed between the external controller and the motor, wherein the internal controller transmits communication to the external controller by modulating the voltage on at least one power phase line, and wherein the external controller transmits communication to the internal controller by modulating the voltage on the at least one power phase line. The external controller generates a motor phase power signal in response to the success of the authentication process; as well as The internal controller applies the motor phase power signal to the motor on at least one power phase line in response to the success of the authentication process.

24. The method of claim 23, wherein the motor further comprises at least one switch coupled between the at least one power phase line and the motor, the at least one switch being under the control of the internal controller of the motor unit, wherein in response to the success of the authentication process, the at least one power phase line is coupled between the motor phase power signal and the motor by closing the switch, thereby applying the motor phase power signal to the motor.

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