Feedforward Control of Multiphase Permanent Magnet DC Motor Drives

Abstract

The present application discloses a feedforward control of a multiphase permanent magnet DC motor drive. A system and method for controlling the output torque of a permanent magnet DC (PMDC) machine includes a PMDC motor and a controller, wherein the PMDC motor includes multiple sets of windings. The PMDC motor is configured to generate an output torque. The controller is configured to: for a first set of windings of the PMDC motor, determine a first voltage command based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; for a second set of windings of the PMDC motor, determine a second voltage command based on a second input torque command signal; and selectively control the PMDC motor according to the first voltage command and the second voltage command.

Description

Technical Field

[0001] The present disclosure is directed to facilitating feed-forward torque and current control of a multi-phase permanent magnet DC motor. Background Art

[0002] Permanent magnet direct current (PMDC) motors (also known as brushed DC motors) are widely used in motion control applications, such as in electric power steering (EPS) systems, power tools, etc. PMDC motors with multiple sets of windings have been developed to provide redundancy in EPS applications. Although these motors are similar to their typical single-winding counterparts, most commonly used winding schemes result in inductive coupling between different sets of windings. This causes the current, and therefore the torque, control behavior of these motors to be different from that of single-winding motors. Therefore, existing control schemes cannot be extended to multi-phase PMDC motors.

[0003] Torque control of a PMDC motor drive is performed by current regulation (via a current measurement circuit) using measured current feedback. For example, feed-forward current and torque control is a mode of controlling a PMDC motor drive. To implement feed-forward control of a PMDC motor, an accurate model of the PMDC motor is required (including nonlinearities such as brush drop voltage). Summary of the invention

[0004] The present disclosure generally relates to facilitating feed-forward torque and current control of a multi-phase permanent magnet direct current (PMDC) motor.

[0005] An aspect of the disclosed embodiment includes a system for controlling the output torque of a PMDC machine. The system includes a PMDC motor and a controller, the PMDC motor including multiple sets of windings. The PMDC motor is configured to generate an output torque. The controller is configured to: for a first set of windings of the PMDC motor, determine a first voltage command based on a first input torque command signal and a back-EMF voltage drop of the first set of windings; for a second set of windings of the PMDC motor, determine a second voltage command based on a second input torque command signal; and selectively control the PMDC motor according to the first voltage command and the second voltage command.

[0006] Another aspect of the disclosed embodiment includes a controller for controlling the output torque of a PMDC motor. The controller is configured to: determine a first voltage command for a first set of windings of a multi-phase PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; determine a second voltage command for a second set of windings of the multi-phase PMDC motor based on a second input torque command signal; and selectively control the multi-phase PMDC motor according to the first voltage command and the second voltage command.

[0007] Another aspect of the disclosed embodiment includes a method for controlling the output torque of a PMDC motor. The method includes: for a first set of windings of a multi-phase PMDC motor, determining a first voltage command based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings. The method also includes: for a second set of windings of the multi-phase PMDC motor, determining a second voltage command based on a second input torque command signal. The method also includes: selectively controlling the multi-phase PMDC motor according to the first voltage command and the second voltage command.

[0008] These and other aspects of the disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure is best understood by the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not drawn to scale. Instead, the sizes of the various features are arbitrarily expanded or reduced for clarity.

[0010] Figure 1 A vehicle in accordance with the principles of the present disclosure is generally shown.

[0011] Figure 2 An example multi-winding permanent magnet direct current (PMDC) machine in accordance with the principles of the present disclosure is generally shown.

[0012] Figure 3 A block diagram of a dual-winding PMDC machine using a mathematical model according to the principles of the present disclosure is generally shown.

[0013] Figure 4 A block diagram of a system for feed-forward current and torque control according to the principles of the present disclosure is generally shown.

[0014] Figure 5 Another block diagram of a system for feed-forward current and torque control according to the principles of the present disclosure is generally shown.

[0015] Figure 6 is a flow chart generally illustrating a feed-forward current and torque control method according to the principles of the present disclosure. DETAILED DESCRIPTION

[0016] The following discussion is directed to various embodiments of the present invention. Although one or more of these embodiments may be preferred, the disclosed embodiments should not be interpreted or otherwise used as limiting the scope of the present disclosure, including the claims. In addition, it will be understood by those skilled in the art that the following description has a wide range of applications, and the discussion of any embodiment is intended only to be an exemplary discussion of that embodiment, and is not intended to imply that the scope of the present disclosure, including the claims, is limited to that embodiment.

[0017] As mentioned above, permanent magnet direct current (PMDC) motors (also known as brushed DC motors) are widely used in motion control applications, such as in electric power steering (EPS) systems, power tools, etc. PMDC motors with multiple sets of windings have been developed to provide redundancy in EPS applications. Although these motors are similar to their typical single-winding counterparts, most commonly used winding schemes result in inductive coupling between the different sets of windings. This causes the current, and therefore torque, control behavior of these motors to be different from that of single-winding motors. Therefore, existing control schemes cannot be extended to multi-phase PMDC motors.

[0018] Torque control of a PMDC motor drive is performed by current regulation (via a current measurement circuit) using measured current feedback. For example, feedforward current and torque control is a mode of controlling a PMDC motor drive. Feedforward control is generally less prone to instability (due to the open-loop nature) and is noise-free because current sensors are generally not required to implement feedforward control. In addition, the noise transmission characteristics of a feedforward control system are lower than other control systems. Therefore, in applications such as EPS systems, power tools, etc., it is beneficial to use feedforward current control to operate a PMDC motor.

[0019] Therefore, it may be desirable to provide a system and method for feedforward control of a PMDC motor drive, such as the system and method described herein. In order to implement feedforward control of a PMDC motor drive, an accurate model of the PMDC motor (including nonlinearity, such as brush voltage drop) is required. For example, in some embodiments, the system and method described herein can be configured to determine or calculate a control signal (e.g., a voltage command) by utilizing an inverse mathematical model of the controlled object (or motor). In particular, the system and method described herein implements feedforward current (torque) control of a multi-phase PMDC motor (e.g., having at least two sets of windings) based on a current command (reference) and a motor speed signal, which can be estimated or measured by a speed sensor, or estimated or measured by differentiating the motor position obtained from a position sensor. In some embodiments, a controller based on a machine model can be based on a substantially similar model of a PMDC machine with estimated parameters. Additionally or alternatively, the speed parameter can be obtained directly from a sensor (position sensor or speed sensor) or an observer output. In some embodiments, a controller based on a transformed machine model can calculate a voltage command using the inverse of a modified machine model. The voltage commands may be mathematically transformed for application to the PMDC machine terminals.

[0020] Figure 1A vehicle 10 is generally shown in accordance with the principles of the present disclosure. Vehicle 10 may include any suitable vehicle, such as a car, truck, sport utility vehicle, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. Although vehicle 10 is illustrated as a passenger vehicle having wheels and used on a road, the principles of the present disclosure may be applied to other vehicles, such as airplanes, ships, trains, drones, or other suitable vehicles.

[0021] The vehicle 10 includes a vehicle body 12 and a hood 14. A passenger compartment 18 is at least partially defined by the vehicle body 12. Another portion of the vehicle body 12 defines an engine compartment 20. The hood 14 is movably attached to a portion of the vehicle body 12 such that the hood 14 provides access to the engine compartment 20 when the hood 14 is in a first position or an open position and covers the engine compartment 20 when the hood 14 is in a second position or a closed position. In some embodiments, the engine compartment 20 may be located in a rearward portion of the vehicle 10 (compared to what is generally shown).

[0022] The passenger compartment 18 may be disposed rearward of the engine compartment 20, but in embodiments where the engine compartment 20 is disposed at a rear portion of the vehicle 10, the passenger compartment 18 may be disposed forward of the engine compartment 20. The vehicle 10 may include any suitable propulsion system, including an internal combustion engine, one or more electric motors (e.g., an electric vehicle), one or more fuel cells, a hybrid (e.g., a hybrid vehicle) propulsion system including a combination of an internal combustion engine, one or more electric motors, and / or any other suitable configuration (e.g., a dual-winding version).

[0023] In some embodiments, the vehicle 10 may include a gasoline fuel engine, such as a spark ignition engine. In some embodiments, the vehicle 10 may include a diesel fuel engine, such as a compression ignition engine. The engine compartment 20 houses and / or surrounds at least some components of the propulsion system of the vehicle 10. Additionally or alternatively, a propulsion control device (e.g., an accelerator actuator (e.g., an accelerator pedal), a brake actuator (e.g., a brake pedal), a steering wheel, and other such components) are disposed in the passenger compartment 18 of the vehicle 10. The propulsion control device may be actuated or controlled by a driver of the vehicle 10 and may be directly connected to corresponding components of the propulsion system, such as a throttle, brake, axle, vehicle transmission, etc. In some embodiments, the propulsion control device may communicate a signal to a vehicle computer (e.g., drive-by-wire), which in turn may control corresponding propulsion components of the propulsion system. Thus, in some embodiments, the vehicle 10 may be an autonomous vehicle.

[0024] In some embodiments, the vehicle 10 includes a transmission that communicates with the crankshaft via a flywheel or a clutch or a fluid coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. In the case of an internal combustion engine or a hybrid vehicle, the vehicle 10 may include one or more pistons that operate in conjunction with the crankshaft to generate force that is transmitted to one or more shafts through the transmission to rotate the wheels 22. When the vehicle 10 includes one or more electric motors, the vehicle battery and / or fuel cell provides energy to the electric motors to rotate the wheels 22.

[0025] The vehicle 10 may include an automatic vehicle propulsion system, such as cruise control, adaptive cruise control, automatic braking control, other automatic vehicle propulsion systems, or combinations thereof. The vehicle 10 may be an automatic or semi-automatic vehicle, or other suitable type of vehicle. The vehicle 10 may include additional features or fewer features than those generally shown and / or disclosed herein.

[0026] In some embodiments, the vehicle 10 may include an Ethernet component 24, a controller area network (CAN) component 26, a media oriented system transport component (MOST) 28, a FlexRay component 30 (e.g., a wire control brake system, etc.), and a local interconnect network component (LIN) 32. In some embodiments, the vehicle 10 is configured for domain control with over-the-air programming support. For example, as described, the vehicle 10 can receive updates for any suitable software components of the vehicle 10 via the Internet (e.g., or other suitable network). The vehicle 10 can update or change the software components based on the update. The vehicle 10 may include more or fewer features than those generally shown and / or disclosed herein.

[0027] In some embodiments, vehicle 10 may include an electric power steering (EPS) system that utilizes a PMDC motor. A PMDC motor may include a stator, a rotor, and a commutator. Typically, the stator contains magnetic poles, while the rotor is an armature that carries windings. The commutator is attached to brushes and slip rings, which allow for mechanical commutation of the PMDC machine. The brushes are connected to phase lead terminals through which voltage can be applied to the PMDC machine. The term "machine" is used interchangeably with the term "motor" herein and refers only to a system (e.g., Figure 2-5 The motor control system 300 shown in FIG. 3 is a PMDC motor (eg, Figure 3-5 PMDC motor 520 shown).

[0028] The mathematical model of a single-winding PMDC machine consists of two control equations that relate the voltage, current and (electromagnetic) torque of the machine as shown below.

[0029]

[0030] e g =K e ω m

[0031] T e =K e i a

[0032] Among them, v, i a and T e are the input voltage, current and electromagnetic torque of the machine, K e , R and L represent the machine back EMF (and torque) constant, motor circuit resistance and inductance, respectively. g represents the back EMF voltage drop, and v b is a non-linear brush voltage drop and is a function of current as shown below.

[0033]

[0034] Among them, V 0 and I 0 is the brush voltage drop parameter. In general, all machine parameters are nonlinear functions of operating temperature and magnetic saturation (caused by high current operation).

[0035] In addition, the electrical parameters of the motor (i.e., back electromotive force constant or torque constant K e , resistance R and inductance L) change dynamically with the operating conditions of the motor. For a given magnet temperature θ m , K e The change can be expressed as:

[0036] K e =γ k (K en (1+α m (θ m -θ n )))

[0037] Among them, γ k is a scaling factor to take into account magnetic saturation and is the motor current i a The function of K en is at temperature θ n K e The nominal (unsaturated) value of α m is a constant representing the thermal coefficient of the permanent magnet material used in the motor.

[0038] The inductance of the motor can be expressed by the following equation:

[0039] L=γ l L n

[0040] Among them, γ L is a scaling factor for the inductance based on the magnetic saturation characteristics of the motor and is the motor current i a function, and L n is the nominal (unsaturated) inductance value.

[0041] In addition, the motor circuit resistance can be described by the following equation:

[0042] R=R f (1+α f (θ f -θ n ))+R m (1+α w (θ w -θ n ))

[0043] Among them, R f is the nominal value of the field effect transistor (FET) resistance, α f is a constant representing the thermal coefficient of the FET, θ f is the temperature of the FET, θ n is the measurement R f The nominal temperature at m is the nominal value of the motor resistance, α w is a constant representing the thermal coefficient of the winding, θ w is the winding temperature, θ n is the measurement R m Nominal temperature at .

[0044] The above equation for resistance provides for the resistance of the motor circuit, not just the resistance of the motor windings. In some embodiments, motor parameters are continuously estimated in real time or near real time, which can result in improved estimates of signals used by the motor control system 300 .

[0045] From the perspective of control system design, the PMDC motor 520 is a controlled object, and as described above, the time domain model of the PMDC motor 520 can be transformed into the s domain:

[0046] V(s)=(LS+R)I a (s(+E g (s)+V B (s)

[0047] The brushes of a PMDC machine are generally susceptible to mechanical wear. Mechanical wear can lead to motor failure, after which the machine will not operate. In an EPS system setting, not using a PMDC motor can result in a loss of assistance to the operator of the vehicle 10. To address this challenge, PMDC motors with multiple sets of windings have been developed to provide system redundancy.

[0048] Figure 2 A motor control system 300 including a multi-winding PMDC machine according to the principles of the present disclosure is generally shown. More specifically, the motor control system 300 is an example of a "double-wound PMDC machine" that includes four stator poles (i.e., two pole pairs (N and S)) 110, two brush pairs (B1-B4) 120, twelve commutator plates and rotor slots (i.e., gaps between rotor poles) 130 corresponding to each other and commutator segments (e.g., 1.1-1.2, 1.3-1.4, 2.1-2.2, 2.3-2.4, 3.1-3.2, and 3.3-3.4) 140, and a distributed shingled winding 150 with a diametrical pitch. It should be noted that the technical solutions described herein are not limited to having Figure 2 The motor control system 300 is not configured as shown. Rather, in other examples, the motor control system 300 can include additional brush pairs 120 and / or pole pairs 110. Alternatively or additionally, in other examples, the motor control system 300 can include a different number of rotor slots 130 or a different arrangement of windings for the commutator segments 140.

[0049] Although multi-winding PMDC motors are similar to their typical single-winding counterparts, most commonly used winding schemes result in inductive coupling between windings of different groups. This results in the current, and thus torque, control behavior of these motors being different from that of single-winding motors. Therefore, existing control schemes for single-winding PMDC motors cannot be extended to multi-phase PMDC motors. Torque control of PMDC motor drives is performed by current regulation (through current measurement circuits) using measured current feedback. For example, feed-forward current and torque control is a mode of controlling a PMDC motor drive. In order to implement feed-forward control of a PMDC motor, an accurate model of the PMDC motor (including nonlinearities, such as brush voltage drop) is required.

[0050] Figure 3 A block diagram of a dual-winding PMDC machine using a mathematical model according to the principles of the present disclosure is generally shown. Figure 3The view of the motor control system 300 in FIG. 1 includes a controller 510 and a PMDC motor 520, in which case the motor 520 includes dual windings. The controller 510 may include any suitable controller, such as a vehicle electronic control unit, a processor, or any other suitable controller, such as those described herein. The controller 510 may communicate with a memory. The memory may include any suitable non-volatile or volatile memory. The memory may include a memory array, a memory storage device, or any other suitable memory. The memory may include instructions that, when executed by the controller 510, cause the controller 510 to: at least control the PMDC motor employed by the system of the vehicle 10. Additionally or alternatively, the instructions, when executed by the controller 510, cause the controller 510 to perform various other functions of the vehicle 10.

[0051] For the dual-winding PMDC motor 520, the two input voltages (V 1 )530a and (V 2 ) 530b may be based on a voltage command generated by the controller 510 (eg, via a power controller (not shown)). It should be noted that, although the voltage command generated by the controller 510 is ideally equal to the input voltage (V 1 )530a and (V 2 )530b, but in practice these values ​​may differ slightly due to, for example, nonlinearities in the power converter circuit. Figure 4 and Figure 5 As discussed in more detail, the controller 510 may be configured to provide a torque control signal based on one or more input torque command signals (e.g., Figure 4 and Figure 5 The input current command and ) determines the voltage command. One or more input torque command signals may be based on the input torque generate.

[0052] In addition, due to the back electromotive force (ω m ) and modify the voltage command. The back electromotive force is based on the speed of the motor 520. For example, the first back electromotive force voltage (ω) of the first set of windings of the motor 520 m )532a is based on the motor speed and the first back EMF (and torque) constant K of the first set of windings e1 Similarly, the second back electromotive force voltage (ω m ) 532b is based on the motor speed and the second set of windings of the second back EMF (and torque) constant K e2 .

[0053] Due to the brush voltage drop (V bd) and further modify the voltage command 530a-530b. For example, the first voltage (V1) 530a is added to the brush voltage drop of the first winding, and the second voltage V 2 This voltage is then converted to a current (I 1 )540a and (I 2 ) 540b, and this current further generates a resultant torque (T e )550. Based on the corresponding constant K of each winding e1 and K e2 , output torque 550 and current I 1 and I 2 In addition, the magnetic coupling between the two windings, represented by the mutual inductance (M), further affects the current generated by the voltage command.

[0054] Due to the additional magnetic coupling between the phases of the dual-winding PMDC machine 300, the machine model of the machine 300 is different from that of a single-winding machine. For example, a mathematical model for a dual-winding PMDC machine 300 is given as follows.

[0055]

[0056]

[0057] T e =K e1 I 1 +K e2 I 2

[0058] Among them, M 12 =M 21 =M, which represents the inductive coupling between the two phases. Usually, the mutual inductance term (M 12 I 2 and M 21 I 1 ) Random machine current I 1 and I 2 Non-linear changes.

[0059] The model can be extended to an n-phase PMDC machine, where n represents the number of windings used (or the number of redundant machines included in a single PMDC machine). The general model of an n-phase machine can be represented as follows.

[0060]

[0061]

[0062]

[0063]

[0064] T e =K e1 I 1 +K e2 I 2 +…+K en I n

[0065] In general, the mutual inductance is specified to be different. The mutual inductance of two sets of windings (for example, set a and set b) is equal (for example, M ab =M ba ).

[0066] For simplicity, the remaining description is for a two-winding machine, which can be extended to a general n-phase machine. The voltage-current equation for a two-winding machine can be expressed in transfer matrix form as follows.

[0067]

[0068]

[0069] Here, the two brush voltage drop terms are assumed to be independent of the current in order to generate a transfer matrix representation of the PMDC machine (since a frequency domain representation of the transfer matrix requires a linear time-invariant model in the time domain). Thus, the output current can be represented in terms of the input voltage as follows.

[0070]

[0071] Δ(s)=(L 1 s+R 1 )(L 2 s+R 2 )-s 2 M 2 =(L 1 L 2 -M 2 )s 2 +(L 1 R 2 +L 2 R 1 )s+R 1 R 2

[0072] When the winding arrangement is symmetrical and the two brush pairs are similar, the above model can be simplified to assume that the half machines are identical (eg, self-inductance, resistance, voltage constant, and brush voltage drop parameters are equal).

[0073] Thus, in the dual-winding PMDC machine 300, the controller 510 uses both windings to generate output torque 550 simultaneously by generating voltage commands that cause the voltages 530a-530b to be generated so that the resulting current results in output torque 550. The controller 510 generates the voltage commands 530a-530b based on the output torque 550 to be generated by the motor 520. In the event of a failure in one winding (e.g., the first winding), the second voltage command 530b causes the second winding to continue to generate the corresponding current 540b, thereby causing at least part of the output torque 550.

[0074] Alternatively or additionally, the controller 510 generates only a single voltage command to cause an input voltage (e.g., first voltage 530a) to generate output torque using only the first winding. In the event of a failure of the first winding, the controller 510 then uses the second winding to generate a voltage command to cause a second input voltage (V 2 )530b's second voltage command is used to generate output torque 550.

[0075] The above model can be extended to n-winding PMDC machines (not just two-winding), where the controller 510 uses n (n is greater than 2) voltage commands V for the n windings. 1 -V n , each voltage command generates a corresponding current I 1 -I n , and together they cause the motor to generate output torque 550.

[0076] It should be noted that the embodiments of the feedforward control for multiphase PMDC motors described herein are applicable to any application using PMDC motors, such as ships, power tools, rotor pumps, and any other such applications. PMDC motor drivers are widely used in industry for low-cost applications. Typically, feedback current control techniques are used for current and torque control of PMDC machines. The technical solutions described herein help to use feedforward control, and thus provide several advantages. For example, when a position sensor or a speed sensor is available, current sensors are not required using feedforward control, thereby saving costs. In addition, due to the open-loop characteristics of the motor control system, feedforward control reduces instability. In addition, feedforward control provides a fault-tolerant control operation of a drive system based on PMDC. Those skilled in the art will readily appreciate other advantages. The technical solutions described herein provide different configurations of feedforward control for PMDC motors that can be used for different applications.

[0077] Feedforward current control uses the motor speed for current control. Although the motor speed can be measured using a speed sensor or obtained by differentiating the position signal measured by a position sensor, it is also possible to estimate the motor speed using an observer.

[0078] Figure 4 A block diagram of a system for feed-forward current (and torque) control according to the principles of the present disclosure is generally shown. Figure 4 In the embodiment of the present invention, the motor control system 300 facilitates feedforward control of the PMDC motor 520 and thereby controls the torque output of the PMDC motor 520. In some embodiments, the motor control system 300 includes a feedforward current controller 510 and other components. The present disclosure uses the term "motor control system" to refer to the feedforward current controller 510 and the PMDC motor 520. In some embodiments, the controller 510 controls the torque output 550 of the PMDC motor 520 by calculating the voltage using the inverse of the machine model of the PMDC motor 520 with estimated parameters and commanded current. Figure 4 Any parameters shown with a tilde in the figure indicate that these parameters can be estimated. These parameters can be estimated in real time by utilizing the temperature and magnetic saturation characteristics of different parts of the PMDC motor 520.

[0079] As shown, the voltage command 530a is based on the input current command 402a. Estimated brush voltage drop 404a and estimated back EMF voltage drop 406a determines. The voltage command 530b is based on the input current command 402b, estimated brush voltage drop 404b and estimated back EMF voltage drop 406b to confirm.

[0080] The controller 510 generates the estimated brush voltage drops 404a and 404b using the following expressions:

[0081]

[0082]

[0083] in, and is the predetermined brush voltage drop parameter, and and is the current command. Although the brush voltage drop estimate is shown as a function of the current command, it can also be estimated by replacing the current command with the measured motor current if motor current measurements are available.

[0084] In addition, the controller 510 determines the resistance of the motor circuit based on the Value and Inductance The estimated value for the input current command 402a and 402b generates 530a and 530b. The resistance and inductance of the motor circuit are predetermined or estimated values. The derivative term An approximation of can be its standard form, such as The derivative term can then be transformed using different techniques (e.g., backward differentiation, bilinear transformation, etc.) Discretize, or the derivative It can be a direct digital derivative design with very targeted gain and phase response to obtain the desired accuracy, complexity, and noise transfer characteristics.

[0085] As depicted, controller 510 determines the motor speed based on a predetermined back EMF constant value and an estimated motor speed. Generates estimated back EMF voltage drop 406a. The motor speed signal can be measured using a speed sensor, or obtained by differentiating the motor position obtained from a position sensor. For example, a speed sensing circuit can monitor the motor speed and provide the detected speed as an input to the controller 510. The speed sensing circuit can have a transfer function that represents the dynamics of the speed sensor. In some embodiments, a low pass filter can use a predetermined cutoff frequency that depends on the motor speed.

[0086] In some embodiments, feedforward control can utilize the speed measured by a position sensor. Position sensing circuitry can monitor the position of the motor and provide the detected position as an input to the controller 510. In some embodiments, the controller 510 includes a motor speed module that calculates an estimated motor speed based on a motor position signal. For example, the motor speed module can calculate the motor speed by differentiating the motor position signal. The motor position signal can provide the angular position of the motor shaft. The derivative implementation for obtaining the estimated motor speed from the motor position signal Can have such as The derivative can then be realized using different techniques (e.g., backward differentiation or bilinear transformation) To discretize, or the derivative realizes It can be a direct digital derivative design with very targeted gain and phase response to obtain the desired accuracy, complexity, and noise transfer characteristics. It should be noted that in other examples, the transfer function representing the dynamics of the position sensor may be different from the first order transfer function shown in the figure depending on the characteristics of the specific sensor.

[0087] In some embodiments, the brush voltage drop parameter may be omitted from the motor control system 300 in an attempt to simplify the controller 510. The motor control system 300 may be extended to any multi-phase machine with more than two sets of windings by expanding the voltage terms associated with the mutual inductance to include cross-coupling between all sets of windings of the multi-phase machine.

[0088] Figure 5 Another exemplary block diagram of a motor control system 300 for feed-forward current (and torque) control according to one or more embodiments is generally shown. The control loop is configured using Figure 5 An alternative mathematical model of the multi-winding machine generally shown in FIG. 1 is implemented as follows.

[0089]

[0090] V + =V 1 +V 2 V - =V 1 -V 2

[0091] I + =V 1 +V 2 V - =V 1 -V 2

[0092] T e =K e I +

[0093] like Figure 5 As generally shown in FIG. 4 , the control logic is implemented based on current sum commands and difference commands as functions of respective current commands. The control loop determines the voltage sum command and the voltage difference command, which are then converted back to respective voltage commands at 410 and applied to the PMDC machine. The current sum control loop includes a current sum command and a difference command for the motor circuit resistance. Value, self-perception Value and Mutual Inductance The feed-forward estimate of the value of And brush voltage drop parameters The current difference loop does not include the last two terms. This alternative mathematical model allows to simplify the control logic implementation of the multiphase PMDC machine.

[0094] Figure 66 is a flow chart generally illustrating a method 600 for controlling a multi-phase PMDC motor according to the principles of the present disclosure. At 602, the method 600 determines a first voltage command for a first set of windings of the multi-phase PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings. For example, the controller 510 determines a first voltage command for a first set of windings of the multi-phase PMDC motor based on the first input torque command signal and a back electromotive force voltage drop of the first set of windings. At 604, the method 600 determines a second voltage command for a second set of windings of the multi-phase PMDC motor based on a second input torque command signal. For example, the controller 510 determines a second voltage command for a second set of windings of the multi-phase PMDC motor based on a second input torque command signal. At 606, the method 600 selectively controls the multi-phase PMDC motor according to the first voltage command and the second voltage command. For example, the controller 510 selectively controls the multi-phase PMDC motor according to the first voltage command and the second voltage command.

[0095] In some embodiments, a system for controlling the output torque of a permanent magnet direct current (PMDC) machine includes: a PMDC motor configured to generate an output torque, the PMDC motor including multiple sets of windings; and a controller configured to: for a first set of windings of the PMDC motor, determine a first voltage command based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; for a second set of windings of the PMDC motor, determine a second voltage command based on a second input torque command signal; and selectively control the PMDC motor according to the first voltage command and the second voltage command.

[0096] In some embodiments, the controller is further configured to determine the first voltage command based on a brush voltage drop of the first set of windings.

[0097] In some embodiments, the controller is further configured to determine the second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

[0098] In some embodiments, the controller is further configured to determine the first voltage command based on an inductance of the circuit of the PMDC motor and a resistance of the circuit of the PMDC motor.

[0099] In some embodiments, the controller is further configured to determine the second voltage command based on an inductance of the circuit of the PMDC motor and a resistance of the circuit of the PMDC motor.

[0100] In some embodiments, the controller is further configured to: determine a voltage value based on the first input torque command signal, the inductance of the PMDC motor's circuit, and the resistance of the PMDC motor's circuit; and calculate the sum of the voltage value of the first set of windings and the back electromotive force voltage drop.

[0101] In some embodiments, the controller is further configured to determine the first voltage command based on the voltage value and a sum of the voltage value, a brush voltage drop of the first set of windings, and a back electromotive force voltage drop of the first set of windings.

[0102] In some embodiments, the controller is further configured to determine a back-EMF voltage drop across the first set of windings using the motor speed signal estimate.

[0103] In some embodiments, the controller is also configured to: apply a first voltage command to a first group of windings, the first group of windings generating a first current in response to the first voltage command; and apply a second voltage command to a second group of windings, the second group of windings generating a second current in response to the second voltage command; wherein the PMDC motor generates an output torque in response to the first current and the second current.

[0104] In some embodiments, the controller is further configured to determine the first voltage command and the second voltage command using a mathematical transformation.

[0105] In some embodiments, a controller for controlling the output torque of a multi-phase permanent magnet direct current (PMDC) motor is configured to: determine a first voltage command for a first group of windings of the multi-phase PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first group of windings; determine a second voltage command for a second group of windings of the multi-phase PMDC motor based on a second input torque command signal; and selectively control the multi-phase PMDC motor according to the first voltage command and the second voltage command.

[0106] In some embodiments, the controller is further configured to determine the first voltage command based on a brush voltage drop of the first set of windings.

[0107] In some embodiments, the controller is further configured to determine the second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

[0108] In some embodiments, the controller is further configured to determine the first voltage command based on an inductance of the circuit of the multi-phase PMDC motor and a resistance of the circuit of the multi-phase PMDC motor.

[0109] In some embodiments, a method for controlling the output torque of a multi-phase permanent magnet direct current (PMDC) motor includes: for a first group of windings of the multi-phase PMDC motor, determining a first voltage command based on a first input torque command signal and a back electromotive force voltage drop of the first group of windings; for a second group of windings of the multi-phase PMDC motor, determining a second voltage command based on a second input torque command signal; and selectively controlling the multi-phase PMDC motor according to the first voltage command and the second voltage command.

[0110] In some embodiments, the method further includes determining the first voltage command based on a brush voltage drop across the first set of windings.

[0111] In some embodiments, the method further includes determining a second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

[0112] In some embodiments, the method further includes determining the first voltage command based on an inductance of the circuit of the multi-phase PMDC motor and a resistance of the circuit of the multi-phase PMDC motor.

[0113] In some embodiments, the method further includes determining a back EMF voltage drop across the first set of windings using the motor speed signal estimate.

[0114] In some embodiments, the method further includes: applying a first voltage command to a first group of windings, the first group of windings generating a first current in response to the first voltage command; and applying a second voltage command to a second group of windings, the second group of windings generating a second current in response to the second voltage command; wherein the multi-phase PMDC motor generates an output torque in response to the first current and the second current.

[0115] The above discussion is intended to illustrate the principles and various embodiments of the present invention. Once the above disclosure is fully understood, many changes and modifications will become apparent to those skilled in the art. It is intended that the following claims be interpreted to include all such changes and modifications.

[0116] The word "example" is used herein to mean used as an example, instance or illustration. Any aspect or design described herein as an "example" is not necessarily to be interpreted as being more preferred or advantageous than other aspects or designs. On the contrary, the use of the word "example" is intended to present the concept in a specific way. As used in this application, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clearly seen from the context, "X includes A or B" is intended to represent any natural inclusive arrangement. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied in any of the foregoing cases. In addition, the article "a / an" used in this application and the appended claims should generally be interpreted as meaning "one or more", unless otherwise specified or clearly pointed to the singular form from the context. In addition, unless so described, the use of the term "embodiment" or "one embodiment" throughout the text is not intended to represent the same embodiment or embodiment.

[0117] The implementation of the systems, algorithms, methods, commands, etc. described herein may be implemented in hardware, software, or any combination thereof. Hardware may include, for example, a computer, an intellectual property (IP) core, an application specific integrated circuit (ASIC), a programmable logic array, an optical processor, a programmable logic controller, microcode, a microcontroller, a server, a microprocessor, a digital signal processor, or any other suitable circuit. In the claims, the term "processor" shall be understood to include any of the foregoing hardware, either alone or in combination. The terms "signal" and "data" may be used interchangeably.

[0118] As used herein, the term module may include a packaged functional hardware unit designed for use with other components, a set of commands executable by a controller (e.g., a processor executing software or firmware), a processing circuit configured to perform a specific function, and a self-contained hardware or software component that interfaces with a larger system. For example, a module may include an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an electrical circuit, a digital logic circuit, an analog circuit, a combination of discrete circuits, gate circuits, and other types of hardware, or a combination thereof. In other embodiments, a module may include a memory that stores commands executable by a controller to implement features of the module.

[0119] Furthermore, in one aspect, for example, the systems described herein may be implemented using a general purpose computer or general purpose processor with a computer program that, when executed, performs any corresponding method, algorithm and / or command described herein. Additionally or alternatively, for example, a special purpose computer / processor may be utilized that may include other hardware for performing any method, algorithm or command described herein.

[0120] In addition, all or part of the implementation of the present disclosure may take the form of a computer program product accessible from, for example, a computer usable or computer readable medium. A computer usable or computer readable medium may be, for example, any device that can tangibly contain, store, communicate, or transport a program for use by or in conjunction with any processor. The medium may be, for example, an electronic, magnetic, optical, electromagnetic device, or a semiconductor device. Other suitable media may also be used.

[0121] The above embodiments, implementations and aspects have been described to allow easy understanding of the present invention and do not limit the present disclosure. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope should be given the broadest interpretation to cover all such modifications and equivalent structures permitted by law.

Claims

1. A system for controlling the output torque of a permanent magnet direct current (PMDC) machine, comprising: A PMDC motor configured to generate the output torque, the PMDC motor comprising a plurality of winding sets; and A controller configured to: determining a first voltage command for a first set of windings of the PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; determining a second voltage command for a second set of windings of the PMDC motor based on a second input torque command signal; as well as selectively controlling the PMDC motor according to the first voltage command and the second voltage command; in The controller is further configured to determine the first voltage command and the second voltage command based on an inductive coupling between the first set of windings and the second set of windings.

2. The system according to claim 1, wherein: The controller is further configured to determine the first voltage command based on a brush voltage drop of the first set of windings.

3. The system according to claim 1, wherein: The controller is further configured to determine the second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

4. The system according to claim 1, wherein: The controller is further configured to determine the first voltage command based on an inductance of an electrical circuit of the PMDC motor and a resistance of an electrical circuit of the PMDC motor.

5. The system according to claim 1, wherein: The controller is further configured to determine the second voltage command based on an inductance of an electrical circuit of the PMDC motor and a resistance of an electrical circuit of the PMDC motor.

6. The system according to claim 1, wherein: The controller is also configured to: determining a voltage value based on the first input torque command signal, an inductance of an electrical circuit of the PMDC motor, and a resistance of an electrical circuit of the PMDC motor; as well as The sum of the back electromotive force voltage drop of the first group of windings and the voltage value is calculated.

7. The system according to claim 6, wherein: The controller is further configured to determine the first voltage command based on the voltage value and a sum of the voltage value, a brush voltage drop of the first set of windings, and a back electromotive force voltage drop of the first set of windings.

8. The system according to claim 1, wherein: The controller is further configured to determine a back-EMF voltage drop across the first set of windings using a motor speed signal estimate.

9. The system according to claim 1, wherein: The controller is also configured to: applying the first voltage command to the first set of windings, the first set of windings generating a first current in response to the first voltage command; and The second voltage command is applied to the second set of windings, and the second set of windings generates a second current in response to the second voltage command; wherein the PMDC motor generates an output torque in response to the first current and the second current.

10. The system according to claim 1, wherein: The controller is further configured to determine the first voltage command and the second voltage command using a mathematical transformation.

11. A controller for controlling the output torque of a multi-phase permanent magnet direct current (PMDC) motor, the controller being configured as follows: determining a first voltage command for a first set of windings of the multi-phase PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; determining a second voltage command for a second set of windings of the multi-phase PMDC motor based on a second input torque command signal; as well as selectively controlling the multi-phase PMDC motor according to the first voltage command and the second voltage command; in The controller is further configured to determine the first voltage command and the second voltage command based on an inductive coupling between the first set of windings and the second set of windings.

12. The controller according to claim 11, wherein: The controller is further configured to determine the first voltage command based on a brush voltage drop of the first set of windings.

13. The controller according to claim 11, wherein: The controller is further configured to determine the second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

14. The controller according to claim 11, wherein: The controller is further configured to determine the first voltage command based on an inductance of an electrical circuit of the multi-phase PMDC motor and a resistance of an electrical circuit of the multi-phase PMDC motor.

15. A method for controlling the output torque of a multi-phase permanent magnet direct current (PMDC) motor, the method comprising: determining a first voltage command for a first set of windings of the multi-phase PMDC motor based on a first input torque command signal and a back electromotive force voltage drop of the first set of windings; determining a second voltage command for a second set of windings of the multi-phase PMDC motor based on a second input torque command signal; as well as selectively controlling the multi-phase PMDC motor according to the first voltage command and the second voltage command; in The first voltage command and the second voltage command are determined based on an inductive coupling between the first group of windings and the second group of windings. 16 . The method of claim 15 , further comprising determining the first voltage command based on a brush voltage drop across the first set of windings. 17 . The method of claim 15 , further comprising determining the second voltage command using a brush voltage drop and a back electromotive force voltage drop of the second set of windings.

18. The method according to claim 15, further comprising: The first voltage command is determined based on an inductance of a circuit of the multi-phase PMDC motor and a resistance of a circuit of the multi-phase PMDC motor.

19. The method according to claim 15, further comprising: A motor speed signal estimate is used to determine a back electromotive force voltage drop across the first set of windings.

20. The method according to claim 15, further comprising: applying the first voltage command to the first set of windings, the first set of windings generating a first current in response to the first voltage command; as well as The second voltage command is applied to the second set of windings, and the second set of windings generates a second current in response to the second voltage command; wherein the multi-phase PMDC motor generates an output torque in response to the first current and the second current.

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