EHA driving and control integrated device based on three-in-one integrated architecture

Abstract

The invention relates to the technical field of electro-hydrostatic actuators, and discloses an EHA driving and control integrated device based on a three-in-one integrated framework, which comprises a power conversion main loop part, a control auxiliary part and a motor M which are connected with one another, the power conversion main loop part comprises a soft start + capacitor, a SiC power component and a common mode inductor, the soft start + capacitor, the SiC power component and the common mode inductor are sequentially connected and are all connected with the control auxiliary part, and the common mode inductor is connected with the motor M; the control auxiliary part comprises an upper computer, an auxiliary power supply, an EHA controller and an actuator; the EHA controller is respectively connected with the upper computer, the auxiliary power supply, a soft start + capacitor, a SiC power assembly, the actuator and a motor M; according to the invention, the motor driving module, the EHA controller and the state monitoring module are integrated in a single shell, precise regulation and control from outside to inside are realized by adopting a three-closed-loop control architecture, the response delay of the system is reduced, and the advantages of compactness, high power density and quick response brought by integration, standardization and efficient heat dissipation design are highlighted.

Description

Technical Field

[0001] This invention relates to the field of electro-hydraulic actuator (EHA) technology, and particularly to an integrated EHA drive and control device based on a three-in-one integrated architecture. Background Technology

[0002] In recent years, electro-hydraulic actuators (EHAs) have been widely used in aerospace, military equipment, and high-end industrial automation. Their core advantage lies in integrating the motor, hydraulic pump, and actuator into a single unit, eliminating the central power source and lengthy piping of traditional hydraulic systems, thus improving system efficiency and reliability. However, existing EHA technology faces key bottlenecks that limit its application in high-precision, high-dynamic-response scenarios, as follows:

[0003] Defects of the split design: Traditional EHA systems adopt a split layout, which has problems such as high energy loss, low reliability and response delay. For example, high-voltage long-distance transmission brings about 15% line loss, and the system efficiency is only 83% to 85%; the cable connection between multiple modules is complicated, there are many points of failure, and the mean time between failures is less than 2000 hours; the signal transmission path is long and the control loop delay exceeds 10ms.

[0004] Insufficient interface standardization: The existing EHA system lacks a unified standard for sensor interfaces, resulting in high adaptation costs. For example, each additional sensor requires an extra 15% to 20% of PCB area; the sampling timing of multi-source sensors is not uniform, and the position-pressure coordinated control error can reach ±1.5%.

[0005] Size and power density limitations: Aerospace equipment has stringent requirements for the size of the EHA (Electronic Power Acquisition System), such as the servo motor installation space of modern fighter jets being ≤0.05m. 3 However, traditional solutions have redundant layouts, exceed volume limits by 30% to 50%, and generally have a power density of ≤0.43kW / kg, which cannot meet the requirements of the new generation of fighter jets of ≥0.7kW / kg. Summary of the Invention

[0006] This invention provides an EHA drive and control integrated device based on a three-in-one integrated architecture, which integrates the motor drive module, EHA controller, and status monitoring module into a single housing. It is also equipped with a standardized multi-protocol sensor interface, which greatly reduces the size and significantly improves the power density. The three-closed-loop control architecture achieves precise control from the outside to the inside, and the system response delay is reduced to ≤5ms. This highlights the advantages of compactness, high power density, and fast response brought by the integrated, standardized, and efficient heat dissipation design.

[0007] This invention provides an EHA drive and control integrated device based on a three-in-one integrated architecture, including an interconnected power conversion main circuit, a control auxiliary circuit, and a motor M;

[0008] The power conversion main circuit includes a soft starter + capacitor, a SiC power component, and a common mode inductor. The soft starter + capacitor, SiC power component, and common mode inductor are connected sequentially and are all connected to the control auxiliary part. The common mode inductor is connected to the motor M. The control auxiliary part includes a host computer, an auxiliary power supply, an EHA controller, and an actuator. The EHA controller is connected to the host computer, the auxiliary power supply, the soft starter + capacitor, the SiC power component, the actuator, and the motor M.

[0009] The SiC power component includes a DC-LINK, a three-phase inverter, a current detection unit, a DC voltage detection unit, a power device drive unit, and a temperature detection unit. The DC-LINK is connected to the three-phase inverter, a soft-start capacitor, and the DC voltage detection unit. The three-phase inverter is also connected to the power device drive unit, the current detection unit, a common-mode inductor, and an EHA controller. The DC voltage detection unit, the temperature detection unit, the power device drive unit, and the current detection unit are all connected to the EHA controller.

[0010] The DC input is regulated by a soft starter and capacitor before being sent to the SiC power module to be inverted into three-phase AC. The current, voltage and temperature are fed back to the EHA controller, which adjusts the drive signals of the power devices in real time to achieve precise control of the motor M. At the same time, the common mode inductor suppresses interference, and the auxiliary power supply ensures the operation of the control circuit.

[0011] Furthermore, in the main power conversion circuit, the soft starter is a current-limiting resistor + relay to avoid power-on surges, and the capacitor is used for filtering and voltage regulation. The large capacitor in the DC-LINK further stabilizes the DC bus voltage, providing a smooth DC source for the inverter. The SiC power module uses a half-bridge two-level inverter, where Q1-Q6 are power devices and D1-D6 are anti-parallel diodes. A high-frequency switch inverts DC to three-phase AC U, V, and W. The SiC power module, in conjunction with a current detection unit, collects the three-phase currents at U1, V1, and W1. A DC voltage detection unit and a temperature detection unit monitor the status. The power device drive unit provides trigger signals to the switching transistors. A common-mode inductor is used to suppress common-mode noise at the inverter output, reducing electromagnetic interference to the motor and the power grid.

[0012] In the control auxiliary section, the EHA controller receives instructions from the host computer and executes the motor control strategy; it collects voltage, current, and temperature signals from the inverter side and adjusts the power device drive in a closed loop; it interacts with the actuator to expand the system functions; and the auxiliary power supply provides low-voltage power to the EHA controller and drive circuit to ensure the normal operation of the control auxiliary section.

[0013] Furthermore, the power conversion main circuit, the control auxiliary circuit, and the control circuit of the motor M include a motor current inner loop, a motor encoder position loop, an actuator position loop, and a hydraulic pressure loop, including a position PI controller, an EHA controller, a PWM drive unit, a DC power supply, a Hall CT, a PMSM, a gear pump, and an actuator cylinder. The position PI controller is connected to the EHA controller and the actuator cylinder respectively. The EHA controller is also connected to the PWM drive unit, the Hall CT, the PMSM, and the gear pump respectively. The PWM drive unit is also connected to the DC power supply, the Hall CT, and the PMSM respectively. The Hall CT, the PMSM, the gear pump, and the actuator cylinder are connected in sequence.

[0014] Enter command X ref The target position of the actuator is represented by the PI controller, which compares the target position with the actuator feedback position X. k The PI algorithm outputs a voltage control signal to achieve closed-loop position regulation. The EHA controller receives this voltage command, as well as the motor current, actuator pressure, and position angle signals fed back by the Hall CT, and coordinates the control of the PWM drive unit. The PWM drive unit, combined with the DC power supply, outputs a PWM signal to drive the permanent magnet synchronous motor (PMSM) to run. The motor drives the gear pump to complete the conversion of electrical energy to mechanical energy and then to hydraulic energy, supplying pressure to the actuator. The actuator receives the pressurized oil to push the piston, outputting load force / displacement, and simultaneously feeding back position + angle and pressure signals.

[0015] Furthermore, the Hall CT detects the motor current for current closed-loop control; the permanent magnet synchronous motor (PMSM) has an encoder Code for detecting the PMSM angular velocity ω to achieve motor speed closed-loop control; the actuator feedback signal constitutes a multivariable closed-loop control.

[0016] In terms of control logic, the outermost layer is the position closed loop, which compares the displacement / angle feedback of the actuator with the target and adjusts the position via PI to ensure the actuator is accurately positioned; the middle layer is the motor control closed loop, where the EHA controller combines the motor current and speed signals to adjust the PWM drive, achieving precise control of motor speed and torque and stabilizing hydraulic output; the inner layer is the current closed loop, which relies on Hall CT to monitor the motor current, prevent overcurrent and improve reliability. Through multiple closed loops, efficient and precise actuation control is achieved.

[0017] Furthermore, in the current closed loop, the controlled object is the phase current of the permanent magnet synchronous motor (PMSM), and its mathematical model is as follows:

[0018]

[0019] Among them, u d u q Indicates the d / q axis voltage (V); i d i qRepresents the d / q axis current (A); R s L represents the stator resistance (Ω); d L q Indicates the d / q axis inductance (H); ω e ω represents electric angular velocity (rad / s). e =n p ×ω m (n p For the extreme logarithm, ω m ψ represents the mechanical angular velocity (rad / s) of a permanent magnet synchronous motor (PMSM). f This indicates the flux linkage (Wb) of a permanent magnet;

[0020] Current closed-loop control is achieved through PI regulation. q →iq ref This refers to torque current tracking, which suppresses current harmonics.

[0021] Furthermore, in the motor control closed loop, the controlled object is the motor speed, and its mathematical model is as follows:

[0022]

[0023] Where, ω m As the mechanical angular velocity (rad / s), its relationship with the encoder detection value ω is ω = ω m / k enc J represents the moment of inertia (kg·m) 2 B represents the damping coefficient (N·m·s / rad); T e T represents electromagnetic torque (N·m); L Indicates load torque (N·m); k enc Encoder resolution (pulse / rad);

[0024] The motor control closed loop outputs i through the speed PI controller. qref , so that ω m →ω ref The value is given by the position closed loop.

[0025] Furthermore, in the position closed loop, the controlled object is the displacement of the actuator cylinder, and its mathematical model is:

[0026]

[0027] F hyd =A p P = A p (β∫Q p dt)

[0028] Q p =D p ω m-C leak P

[0029] Where x represents the displacement of the actuator cylinder (m), corresponding to the feedback signal X. k ; m represents the load mass (kg); F hyd Indicates hydraulic thrust (N); A p Expressed as piston area (m²) 2 P represents the oil pressure (Pa), which is determined by the gear pump flow rate Q. p Integral result: D p Indicates the displacement of the gear pump (m) 3 / rad); C leak Represents the system leakage coefficient (m) 3 / (s·Pa));

[0030] The position closed loop outputs ω through the position PI controller. ref , so that x→X ref , that is, the instruction location.

[0031] Furthermore, the control flow of the control loop is as follows:

[0032] (1) Command input: Given target position X ref ;

[0033] (2) Position closed-loop operation, calculate error e x :

[0034] e x =X ref -X k

[0035] The expression for PI control:

[0036] ω ref =K px ×e x +K ix (∫e x dt)

[0037] Among them, K px K ix For the position loop PI parameters;

[0038] (3) Motor control closed-loop operation, obtain encoder feedback ω, and calculate error e. ω :

[0039] e ω =ω ref -ω e

[0040] The expression for the PI control output q-axis current command:

[0041] iqref =K pω ×e ω +K iω (∫e ω dt)

[0042] Among them, K pω K iω These are the closed-loop PI parameters for motor control.

[0043] (4) Current closed-loop operation, i is detected by Hall sensor. d i q Calculate the voltage command and generate the PWM wave:

[0044] u q =K pi ×(i qref -i q )+K ii (∫(i qref -i q )dt)

[0045] The inverter is driven by SVPWM modulation in the formula;

[0046] (5) Hydraulic actuation, PMSM drives gear pump to generate flow rate Q p →Actuator cylinder pressure P→Output displacement x, real-time feedback of x, ω, i q A closed loop is formed.

[0047] Furthermore, the PI parameter tuning method is as follows: current closed-loop bandwidth > motor control closed-loop bandwidth > position closed-loop bandwidth; current closed-loop response time ≤ 1ms, motor control closed-loop ≤ 5ms, position closed-loop ≤ 20ms;

[0048] The anti-saturation strategy is set as follows: position closed-loop output limiting: |ω| ref |≤ω max ω max Rated speed of the motor; motor control closed-loop output limit: |i qref |≤i max i max This represents the peak current of the motor.

[0049] Adding a feedforward term ω to dynamic compensation ref_ff The expression:

[0050]

[0051] Where, k hyd Indicates hydraulic gain.

[0052] Furthermore, the outermost position closed loop compares the target position command X... ref With actuator displacement feedback Xk The speed command ω is generated by the PI controller. ref This ensures accurate tracking of load displacement.

[0053] The intermediate layer motor control closed loop receives ω ref The motor speed ω, fed back from the encoder, is used to adjust the output q-axis current command i via a PI controller. qref To stabilize the motor speed and ensure hydraulic power output;

[0054] The innermost current closed loop is based on i qref and the q-axis current i detected by the Hall sensor q The voltage command u is generated by PI control. q Directly controlling the motor torque serves as the inner loop with a response time of ≤1ms, forming the core foundation for dynamic stability.

[0055] The three-ring cascade forms a coordinated control chain of "displacement-speed-torque" to achieve precise adjustment from macroscopic position to microscopic current.

[0056] The beneficial effects of this invention are as follows:

[0057] 1. The SiC devices used in this invention have fast switching speed and low loss, improving system efficiency; their high-frequency characteristics are suitable for motor control, reducing the size and cost of magnetic components and increasing power density. SiC has a large bandgap, high breakdown electric field, withstand voltage of 1200V-6500V, excellent high-temperature stability, and is suitable for complex operating conditions, reducing thermal management difficulty and extending system life.

[0058] 2. This invention integrates NTC temperature sensors, etc., which facilitates system integration; high-frequency switching reduces the volume of passive components by more than 30%, and combined with the small size advantage of SiC modules, it greatly reduces the overall size and weight of inverters and systems, which is conducive to lightweight equipment design.

[0059] 3. The EHA controller of this invention integrates rich interfaces, which can flexibly interact with host computers and actuators, support a variety of motor control strategies and algorithms, and adapt to different motors and application scenarios, such as industrial drives and new energy vehicles, thereby shortening the R&D cycle and reducing development difficulty.

[0060] 4. This invention employs a three-loop control architecture to achieve precise control from the outside in. The outermost layer is the position closed loop, which compares the displacement / angle feedback of the actuator with the target and adjusts the position via PI to ensure the actuator is accurately positioned. The middle layer is the motor control closed loop, where the EHA controller combines the motor current and speed signals to adjust the PWM drive, achieving precise control of the motor speed and torque and stabilizing the hydraulic output. The innermost layer is the current closed loop, which relies on Hall CT to monitor the motor current, preventing overcurrent and improving reliability. The three loops are cascaded to form a coordinated control chain of "displacement-speed-torque," achieving step-by-step precise adjustment from macroscopic position to microscopic current. Attached Figure Description

[0061] Figure 1 This is a block diagram of the overall composition of the EHA device in this invention.

[0062] Figure 2 This is a control block diagram of the EHA device in this invention.

[0063] Figure 3 This is a flowchart of the three-loop control of the EHA system in this invention.

[0064] Figure 4 This is a structural diagram of the copper cold plate used in the EHA device of this invention.

[0065] Figure 5 This is a control flowchart of the EHA device in this invention.

[0066] Figure 6 This is a software flowchart of the initialization process of the EHA device in this invention.

[0067] Figure 7 This is a physical diagram of the EHA device in this invention.

[0068] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0069] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0070] This invention discloses an integrated EHA drive and control device based on a three-in-one integrated architecture. Its core feature lies in the highly integrated drive and control unit, which integrates the motor drive module, EHA controller, and status monitoring module into a single housing. It is also equipped with a standardized multi-protocol sensor interface, supporting 4-20mA / CAN / RS485 hybrid access, and employs a distributed heat dissipation channel design, achieving a three-dimensional staggered layout of water-cooled pipes and circuit boards. Its technical effects are significant. Compared with traditional split designs, it greatly reduces volume, significantly improves power density, and reduces system response latency to ≤5ms, highlighting the compact, high power density, and fast response advantages brought by integrated, standardized, and efficient heat dissipation design. It is suitable for integrated electro-hydraulic servo drive control systems in aerospace and military equipment, providing an integrated drive and control solution under high-pressure direct drive (550-750VDC) conditions.

[0071] This invention provides an EHA drive and control integrated device based on a three-in-one integrated architecture, such as... Figure 1 , 7As shown, the architecture diagram of the half-bridge two-level inverter and control system based on SiC (silicon carbide) power components includes an interconnected power conversion main circuit, a control auxiliary circuit, and a motor M. Wherein:

[0072] (1) Power conversion main circuit section ( Figure 1 (Upper half)

[0073] The power conversion main circuit includes a soft starter capacitor, a SiC power module (using a half-bridge two-level inverter), and a common-mode inductor. The soft starter capacitor, SiC power module, and common-mode inductor are connected in sequence and are all connected to the control auxiliary part. The common-mode inductor is connected to the motor M.

[0074] The SiC power component includes a DC-LINK, a three-phase inverter, a current detection unit, a DC voltage detection unit, a power device drive unit, and a temperature detection unit. The DC-LINK is connected to the three-phase inverter, a soft-start capacitor, and the DC voltage detection unit. The three-phase inverter is also connected to the power device drive unit, the current detection unit, a common-mode inductor, and an EHA controller. The DC voltage detection unit, the temperature detection unit, the power device drive unit, and the current detection unit are all connected to the EHA controller.

[0075] A "soft start" (usually a current-limiting resistor + relay) avoids power-on surges, while capacitors are used for filtering and voltage regulation. In DC-LINK, large capacitors further stabilize the DC bus voltage, providing a smooth DC source for the inverter. The SiC-based half-bridge two-level inverter uses SiC MOSFETs and other power devices (Q1-Q6) and anti-parallel diodes (D1-D6). High-frequency switching converts DC to three-phase AC (U, V, W). The high-frequency and high-efficiency characteristics of SiC devices enhance system performance. Current sensing (at U1, V1, W1) collects three-phase current, while DC voltage and temperature sensing monitor system status. The power device drive circuit provides trigger signals to the switching transistors. A common-mode inductor suppresses common-mode noise at the inverter output, reducing electromagnetic interference to the motor and grid, and improving system electromagnetic compatibility.

[0076] (2) Control auxiliary section Figure 1 (Lower half)

[0077] The control auxiliary part includes a host computer, an auxiliary power supply, an EHA controller, and an actuator. The EHA controller is connected to the host computer, the auxiliary power supply, the soft starter + capacitor, the SiC power component, the actuator, and the motor M.

[0078] The EHA controller acts as the system's "brain," receiving commands from the host computer (such as serial port and CAN communication), executing motor control strategies (speed regulation, torque control, etc.), collecting voltage, current, and temperature signals from the inverter side, and adjusting the power device drive in a closed loop. It interacts with actuators to expand system functions (such as servo control and status feedback). The auxiliary power supply provides low-voltage power to the controller, drive circuits, etc., ensuring the normal operation of the control section.

[0079] The key parameters of the EHA device are:

[0080] a. Drive layer: SiC inverter + LC filter (parameters: L=50μH±5%, C=100μF@1200V);

[0081] b. Control layer: DSP architecture (AVP32F335QP176S);

[0082] c. Monitoring layer: CAN communication, RS485 communication.

[0083] The overall logic of the EHA device is as follows: After the DC input is regulated by "soft start + capacitor → DC-LINK", it is sent to the SiC inverter to be inverted into three-phase AC. The current / voltage / temperature is detected and fed back to the EHA controller. The controller adjusts the drive signals of the power devices in real time to achieve precise motor control. At the same time, the common mode inductor suppresses interference, and the auxiliary power supply ensures the operation of the control circuit. It is a motor drive system that integrates "power electronic conversion + automatic control". The application of SiC devices has the advantages of high frequency and high efficiency.

[0084] The integrated design of the EHA unit offers the following advantages:

[0085] 1) High performance. SiC devices have fast switching speed and low loss (no tail current, switching loss is reduced by about 70% compared to IGBT), improving system efficiency; high frequency characteristics (supporting above 100kHz) are suitable for motor control, reducing the size and cost of magnetic components, and achieving higher power density.

[0086] 2) Enhanced reliability: SiC has a large bandgap (3.3eV), a high breakdown electric field (10 times that of silicon), a withstand voltage of 1200V-6500V, and excellent high-temperature stability (junction temperature withstand 175-200℃). It is suitable for complex operating conditions, reduces the difficulty of thermal management, and extends system life.

[0087] 3) Integration and miniaturization: Integration of NTC temperature sensors, etc., facilitates system integration; high-frequency switching reduces the volume of passive components (inductors, capacitors, etc.) by more than 30%, and combined with the small size advantage of SiC modules, significantly reduces the overall size and weight of inverters and systems, which is conducive to lightweight equipment design.

[0088] 4) Excellent control and adaptability: The EHA controller integrates rich interfaces, which can flexibly interact with host computers and actuators, support a variety of motor control strategies and algorithms, adapt to different motors and application scenarios (such as industrial drives, new energy vehicles, etc.), shorten the R&D cycle and reduce development difficulty.

[0089] 5) Cost optimization potential: The high frequency and high efficiency of SiC devices reduce the cost of heat dissipation and magnetic components; driven by the mass production of 8-inch wafers, the cost is gradually decreasing, and the high reliability reduces maintenance costs, resulting in a better total life cycle cost.

[0090] The control circuit of the EHA device (power conversion main circuit, control auxiliary circuit, and motor M) includes the motor current inner loop, motor encoder position loop, actuator position loop, and hydraulic pressure loop, such as... Figure 2 The diagram shows the control block diagram of the EHA device, which includes a position PI controller, an EHA controller, a PWM drive unit, a DC power supply, a Hall CT, a PMSM, a gear pump, and an actuator. The position PI controller is connected to the EHA controller and the actuator. The EHA controller is also connected to the PWM drive unit, the Hall CT, the PMSM, and the gear pump. The PWM drive unit is also connected to the DC power supply, the Hall CT, and the PMSM. The Hall CT, the PMSM, the gear pump, and the actuator are connected in sequence.

[0091] according to Figure 2 The closed-loop control system architecture of the EHA device shown illustrates its purpose: precise control of the actuator output to achieve displacement / force control of the load. The core logic can be broken down as follows: The electro-hydraulic actuator (EHA) closed-loop control system aims to precisely control the actuator output and achieve load displacement / force control. Input command (X) ref The position PI controller compares the target position with the actuator feedback position (X). k The PI algorithm outputs a voltage control signal to achieve closed-loop position regulation. The EHA controller receives this voltage command, as well as signals such as motor current (Hall CT feedback), actuator pressure, and position angle, and coordinates the control of the PWM drive unit. The PWM drive unit, combined with the DC power supply, outputs a PWM signal to drive the permanent magnet synchronous motor (PMSM) to operate. The motor drives the gear pump, completing the conversion of electrical energy to mechanical energy and then to hydraulic energy to supply pressure to the actuator. The actuator receives the pressurized oil to push the piston, outputting load force / displacement, and simultaneously feeding back "position + angle" and "pressure" signals.

[0092] In terms of sensors, Hall effect current CT detects motor current for current closed-loop control; encoder (Code) detects PMSM angular velocity (ω) to achieve motor speed closed-loop control; and actuator feedback signal constitutes multivariable closed-loop control.

[0093] In terms of control logic, the outermost layer is the position closed loop, which compares the displacement / angle feedback of the actuator with the target and adjusts the position via PI to ensure the actuator is accurately positioned; the middle layer is the motor control closed loop, where the EHA controller combines the motor current and speed signals to adjust the PWM drive, achieving precise control of motor speed and torque, and stabilizing hydraulic output; the inner layer is the current closed loop, which relies on Hall CT to monitor the motor current, preventing overcurrent and improving reliability. Through multiple closed loops, efficient and precise actuation control is achieved.

[0094] The mathematical model for the three-closed-loop control of the EHA device is as follows:

[0095] (1) In the current closed loop (inner current loop, innermost layer), the controlled object is the phase current of the permanent magnet synchronous motor (PMSM), and its mathematical model is:

[0096]

[0097] Among them, u d u q Indicates the d / q axis voltage (V); i d i q Represents the d / q axis current (A); R s L represents the stator resistance (Ω); d L q Indicates the d / q axis inductance (H); ω e ω represents electric angular velocity (rad / s). e =n p ×ω m (n p For the extreme logarithm, ω m ψ represents the mechanical angular velocity (rad / s) of a permanent magnet synchronous motor (PMSM). f This indicates the flux linkage (Wb) of a permanent magnet;

[0098] Current closed-loop control is achieved through PI regulation. q →iq ref (Torque current tracking) suppresses current harmonics.

[0099] (2) In the motor control closed loop (speed middle loop, intermediate layer), the controlled object is the motor speed, and its mathematical model is:

[0100]

[0101] Where, ω m As the mechanical angular velocity (rad / s), its relationship with the encoder detection value ω is ω = ω m / k enc J represents the moment of inertia (kg·m) 2B represents the damping coefficient (N·m·s / rad); T e T represents electromagnetic torque (N·m); L Indicates load torque (N·m); k enc Encoder resolution (pulse / rad);

[0102] The motor control closed loop outputs i through the speed PI controller. qref , so that ω m →ω ref (Given by the location loop).

[0103] (3) In the position closed loop (position outer loop, outermost layer), the controlled object is the displacement of the actuator cylinder, and its mathematical model is:

[0104]

[0105] F hyd =A p P = A p (β∫Q p dt)

[0106] Q p =D p ω m -C leak P

[0107] Where x represents the displacement of the actuator cylinder (m), corresponding to the feedback signal X. k ; m represents the load mass (kg); F hyd Indicates hydraulic thrust (N); A p Expressed as piston area (m²) 2 P represents the oil pressure (Pa), which is determined by the gear pump flow rate Q. p Integral result: D p Indicates the displacement of the gear pump (m) 3 / rad); C leak Represents the system leakage coefficient (m) 3 / (s·Pa));

[0108] The position closed loop outputs ω through the position PI controller. ref , so that x→X ref (Instruction location).

[0109] The control process of the EHA device is as follows:

[0110] (1) Command input: Given target position X ref (e.g., 10mm stroke);

[0111] (2) Position closed-loop operation, calculate error e x :

[0112] e x =X ref -X k

[0113] The expression for PI control:

[0114] ω ref =K px ×e x +K ix (∫e x dt)

[0115] Among them, K px K ix For the position loop PI parameters;

[0116] (3) Motor control closed-loop operation, obtain encoder feedback ω, and calculate error e. ω :

[0117] e ω =ω ref -ω e

[0118] The expression for the PI control output q-axis current command:

[0119] i qref =K pω ×e ω +K iω (∫e ω dt)

[0120] Among them, K pω K iω These are the closed-loop PI parameters for motor control.

[0121] (4) Current closed-loop operation, i is detected by Hall sensor. d i q Calculate the voltage command and generate the PWM wave:

[0122] u q =K pi ×(i qref -i q )+K ii (∫(i qref -i q )dt)

[0123] The inverter is driven by SVPWM modulation in the formula;

[0124] (5) Hydraulic actuation, PMSM drives gear pump to generate flow rate Q p →Actuator cylinder pressure P→Output displacement x, real-time feedback of x, ω, i q A closed loop is formed.

[0125] The key parameters of the EHA device are designed as follows:

[0126] (1) The PI parameter tuning method is: current closed loop bandwidth > motor control closed loop bandwidth > position closed loop bandwidth (e.g., typical ratio 5:3:1); current closed loop response time ≤1ms, motor control closed loop ≤5ms, position closed loop ≤20ms;

[0127] (2) Set the anti-saturation strategy as follows: Position closed-loop output limiting: |ω ref |≤ω max ω max Rated speed of the motor; motor control closed-loop output limit: |i qref |≤i max i max This represents the peak current of the motor.

[0128] (3) Adding a feedforward term ω to dynamic compensation ref_ff The expression:

[0129]

[0130] Where, k hyd Indicates hydraulic gain.

[0131] like Figure 3 The diagram shown is a three-loop control flowchart of the EHA system. According to... Figure 3 It can be seen that the EHA system adopts a three-closed-loop control architecture to achieve precise control from the outside to the inside: the outermost layer is the position closed loop, which compares the target position command X... ref With actuator displacement feedback X k The speed command ω is generated by the PI controller. ref This ensures accurate tracking of load displacement; the intermediate layer motor control closed loop receives ω. ref The motor speed ω, fed back from the encoder, is used to adjust the output q-axis current command i via a PI controller. qref To stabilize the motor speed and ensure hydraulic power output; the innermost current closed loop is based on i qref and the q-axis current i detected by the Hall sensor q The voltage command u is generated by PI control. q Directly controlling the motor torque, as the inner loop with the fastest response (≤1ms), forms the core foundation for the system's dynamic stability. The three cascaded loops form a coordinated control chain of "displacement-speed-torque," achieving precise step-by-step adjustment from macroscopic position to microscopic current.

[0132] Figure 4 The diagram shows the structure of the copper cold plate used in the EHA unit. The advantages of its copper cold plate design (water-cooled plate, used in the heat dissipation system) are as follows:

[0133] (1) High efficiency heat dissipation: The meandering pipeline increases the cooling water flow, extends the heat exchange time, increases the contact area with the copper cold plate, improves the heat transfer efficiency, enhances the heat dissipation capacity, and is suitable for high heat flux density scenarios of EHA devices.

[0134] (2) Uniform temperature: The flow of cooling water carries away heat, and the reasonable pipeline layout makes the temperature distribution of the cold plate more uniform, avoiding local overheating, ensuring the stable working temperature of each component of the EHA device, and improving the reliability of the system.

[0135] (3) Compact structure: Efficient heat dissipation is achieved through pipe bending within the limited space of the cold plate, without significantly increasing the volume, which meets the requirements of EHA device for compact layout and lightweight.

[0136] (4) Strong adaptability: The pipeline route and aperture can be flexibly designed according to the location of the heat-generating components and heat flux density of the EHA device, and the heat dissipation can be optimized in a targeted manner to adapt to different working conditions and structural requirements.

[0137] (5) Material advantages: Copper has a high thermal conductivity, which can quickly conduct heat to cooling water. Combined with the pipeline design, it can transfer and dissipate heat in a timely manner, which helps the thermal management of EHA device.

[0138] The multi-dimensional feedback mechanism (full-link closed-loop control) of the EHA device is shown in Table 1:

[0139] Table 1. Multi-dimensional end-to-end closed-loop control mechanism of EHA device

[0140] Feedback type sensor Corresponding control loop effect Location feedback Displacement sensor Position ring (outer ring) Ensure accurate displacement of the actuator cylinder Speed ​​feedback encoder Speed ​​ring (middle ring) Stabilize motor speed to ensure hydraulic output Current feedback Hall sensor Current loop (inner loop) Control motor torque and provide overcurrent protection. Pressure feedback (optional) pressure sensor Extended monitoring Load status monitoring (e.g., overload protection)

[0141] Figure 5 The control flow diagram of the EHA device is shown below, and its control flow is explained as follows:

[0142] Step 1: Start. The starting point for the process.

[0143] Step 2: Initialize peripherals. Initialize the relevant external components and interfaces of the device to prepare for future upgrades and ensure the hardware environment is ready.

[0144] Step 3: Check upgrade conditions. Determine if the device meets the upgrade prerequisites (such as battery level, network, current status, etc.). If not, redirect to the app to end the upgrade process; otherwise, proceed to the next step.

[0145] Step 4: Check upgrade version information. Obtain and verify the relevant data of the version to be upgraded (version number, integrity, etc.) to prepare for the upgrade.

[0146] Step 5: Receive the software upgrade package. Download and receive the required software upgrade files for your device from the server or designated channel.

[0147] Step 6: Software Upgrade Package Verification. Verify the integrity and legitimacy of the upgrade package (e.g., signature, hash value verification) to prevent corrupted or tampered packages from being used for the upgrade; if verification fails, "request resend" to obtain the upgrade package again; if successful, proceed to the next step.

[0148] Step 7: Write to FLASH. Write the verified upgrade package data to the device's FLASH storage chip to update the software program.

[0149] Step 8: Read FLASH. After writing, read the FLASH content to verify that the writing was correct and complete.

[0150] Step 9: Upgrade Package Verification. Perform a full verification of the written program again to confirm whether the upgrade is valid; if the verification fails, "resubmit"; if it passes, proceed to the next step.

[0151] Step 10: Reread version information. Read the current actual version of the device to confirm whether it matches the version to be upgraded, and verify the upgrade result.

[0152] Step 11: End. The process ends when the upgrade is complete or the process terminates due to unmet conditions.

[0153] Figure 6 The software flowchart for the initialization phase of the EHA device is shown below:

[0154] Step 1: Start. The process begins, and the equipment is powered on and ready to run.

[0155] Step 2: Connect the 24V auxiliary power supply to the control circuit and allow the control section of the equipment to operate.

[0156] Step 3: Check peripherals and initialize DIDO. Check the status of external devices (sensors, interfaces, etc.), initialize the digital input / output (DIDO) module, and ensure that the hardware and communication interfaces are ready.

[0157] Step 4: Input DC bus voltage V_ref. The DC bus voltage (e.g., main power supply voltage) to be connected to the acquisition device is denoted as V_ref, and will be used as the basis for subsequent judgments.

[0158] Step 5: Soft Startup (within the dashed box):

[0159] Step 51: Soft start relay K1 closes (input relay K2 turns off). First, "soft start" is initiated through K1. At this time, K2 is open to limit the initial current and avoid direct impact from large voltage.

[0160] Step 52: The voltage V_qu on the drive module side gradually increases. Because K1 is connected, the voltage V_qu of the drive module (such as the power module) slowly and gradually increases, achieving a "soft start" and protecting the equipment.

[0161] Step 53: Determine if V_qu > 0.8 * V_ref. Continuously monitor V_qu. When it exceeds 80% of the DC bus voltage V_ref, it indicates that the soft start is almost complete; otherwise, continue waiting for the voltage to rise.

[0162] Step 54: Input relay K2 closes, with a 50ms delay (soft start relay K1 opens). After V_qu reaches the target, K2 closes to fully conduct the main circuit. After a 50ms delay, K1 opens, the soft start ends, and the device enters normal power supply mode.

[0163] Step 6: End. The soft start process is complete, the device startup phase is over, and it can now proceed with normal operation.

[0164] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0165] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An EHA drive and control integrated device based on a three-in-one integrated architecture, characterized in that, It includes the interconnected power conversion main circuit, control auxiliary circuit and motor M; The power conversion main circuit includes a soft starter + capacitor, a SiC power component, and a common mode inductor. The soft starter + capacitor, SiC power component, and common mode inductor are connected sequentially and are all connected to the control auxiliary part. The common mode inductor is connected to the motor M. The control auxiliary part includes a host computer, an auxiliary power supply, an EHA controller, and an actuator. The EHA controller is connected to the host computer, the auxiliary power supply, the soft starter + capacitor, the SiC power component, the actuator, and the motor M. The SiC power component includes a DC-LINK, a three-phase inverter, a current detection unit, a DC voltage detection unit, a power device drive unit, and a temperature detection unit. The DC-LINK is connected to the three-phase inverter, a soft-start capacitor, and the DC voltage detection unit. The three-phase inverter is also connected to the power device drive unit, the current detection unit, a common-mode inductor, and an EHA controller. The DC voltage detection unit, the temperature detection unit, the power device drive unit, and the current detection unit are all connected to the EHA controller. The DC input is regulated by a soft starter and capacitor before being sent to the SiC power module to be inverted into three-phase AC. The current, voltage and temperature are fed back to the EHA controller, which adjusts the drive signals of the power devices in real time to achieve precise control of the motor M. At the same time, the common mode inductor suppresses interference, and the auxiliary power supply ensures the operation of the control circuit.

2. The EHA drive and control integrated device based on a three-in-one integrated architecture as described in claim 1, characterized in that, In the main power conversion circuit, the soft starter consists of a current-limiting resistor and a relay to prevent power-on surges, while the capacitor is used for filtering and voltage regulation. In the DC-LINK circuit, a large capacitor further stabilizes the DC bus voltage, providing a smooth DC source for the inverter. The SiC power module employs a half-bridge two-level inverter, where Q1-Q6 are power devices and D1-D6 are anti-parallel diodes. A high-frequency switch converts DC to three-phase AC (U, V, W). The SiC power module, in conjunction with a current detection unit, collects the three-phase currents at U1, V1, and W1. A DC voltage detection unit and a temperature detection unit monitor the status. The power device drive unit provides trigger signals to the switching transistors. A common-mode inductor is used to suppress common-mode noise at the inverter output, reducing electromagnetic interference to the motor and the power grid. In the control auxiliary section, the EHA controller receives instructions from the host computer and executes the motor control strategy; it collects voltage, current, and temperature signals from the inverter side and adjusts the power device drive in a closed loop; it interacts with the actuator to expand the system functions; and the auxiliary power supply provides low-voltage power to the EHA controller and drive circuit to ensure the normal operation of the control auxiliary section.

3. The EHA drive and control integrated device based on a three-in-one integrated architecture as described in claim 1, characterized in that, The power conversion main circuit, the control auxiliary circuit, and the control circuit of motor M include a motor current inner loop, a motor encoder position loop, an actuator position loop, and a hydraulic pressure loop. It includes a position PI controller, an EHA controller, a PWM drive unit, a DC power supply, a Hall CT, a PMSM, a gear pump, and an actuator cylinder. The position PI controller is connected to the EHA controller and the actuator cylinder. The EHA controller is also connected to the PWM drive unit, the Hall CT, the PMSM, and the gear pump. The PWM drive unit is also connected to the DC power supply, the Hall CT, and the PMSM. The Hall CT, PMSM, gear pump, and actuator cylinder are connected sequentially. Enter command X ref The target position of the actuator is represented by the PI controller, which compares the target position with the actuator feedback position X. k The PI algorithm outputs a voltage control signal to achieve closed-loop position regulation. The EHA controller receives this voltage command, as well as the motor current, actuator pressure, and position angle signals fed back by the Hall CT, and coordinates the control of the PWM drive unit. The PWM drive unit, combined with the DC power supply, outputs a PWM signal to drive the permanent magnet synchronous motor (PMSM) to run. The motor drives the gear pump to complete the conversion of electrical energy to mechanical energy and then to hydraulic energy, supplying pressure to the actuator. The actuator receives the pressurized oil to push the piston, outputting load force / displacement, and simultaneously feeding back position + angle and pressure signals.

4. The EHA drive and control integrated device based on a three-in-one integrated architecture as described in claim 3, characterized in that, The Hall CT detects the motor current for current closed-loop control; the permanent magnet synchronous motor (PMSM) has an encoder Code for detecting the PMSM angular velocity ω to achieve motor speed closed-loop control; the actuator feedback signal constitutes a multivariable closed-loop control. In terms of control logic, the outermost layer is the position closed loop, which compares the displacement / angle feedback of the actuator with the target and adjusts the position via PI to ensure the actuator is accurately positioned; the middle layer is the motor control closed loop, where the EHA controller combines the motor current and speed signals to adjust the PWM drive, achieving precise control of motor speed and torque and stabilizing hydraulic output; the inner layer is the current closed loop, which relies on Hall CT to monitor the motor current, prevent overcurrent and improve reliability. Through multiple closed loops, efficient and precise actuation control is achieved.

5. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 4, characterized in that, In the current closed loop, the controlled object is the phase current of the permanent magnet synchronous motor (PMSM), and its mathematical model is as follows: Among them, u d u q Indicates the d / q axis voltage (V); i d i q Represents the d / q axis current (A); R s L represents the stator resistance (Ω); d , L q Indicates the d / q axis inductance (H); ω e ω represents electric angular velocity (rad / s). e =n p ×ω m (n p For the extreme logarithm, ω m ψ represents the mechanical angular velocity (rad / s) of a permanent magnet synchronous motor (PMSM). f This indicates the flux linkage (Wb) of a permanent magnet; Current closed-loop control is achieved through PI regulation. q →iq ref This refers to torque current tracking, which suppresses current harmonics.

6. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 5, characterized in that, In the motor control closed loop, the controlled object is the motor speed, and its mathematical model is as follows: Where, ω m As the mechanical angular velocity (rad / s), its relationship with the encoder detection value ω is ω = ω m / k enc J represents the moment of inertia (kg·m) 2 B represents the damping coefficient (N·m·s / rad); T e T represents electromagnetic torque (N·m); L Indicates load torque (N·m); k enc Encoder resolution (pulse / rad); The motor control closed loop outputs i through the speed PI controller. qref , so that ω m →ω ref The value is given by the positional closed loop.

7. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 6, characterized in that, In the position closed loop, the controlled object is the displacement of the actuator cylinder, and its mathematical model is as follows: F hyd =A p P=A p (β∫Q p date) Q p =D p ω m -C leak P Where x represents the displacement of the actuator cylinder (m), corresponding to the feedback signal X. k ; m represents the load mass (kg); F hyd Indicates hydraulic thrust (N); A p Expressed as piston area (m²) 2 P represents the oil pressure (Pa), which is determined by the gear pump flow rate Q. p Integral result: D p Indicates the displacement of the gear pump (m) 3 / rad); C leak Represents the system leakage coefficient (m) 3 / (s·Pa)); The position closed loop outputs ω through the position PI controller. ref , so that x→X ref , that is, the instruction location.

8. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 7, characterized in that, The control flow of the control loop is as follows: (1) Command input: Given target position X ref ; (2) Position closed-loop operation, calculate error e x : e x =X ref -X k The expression for PI control: ω ref =K px ×e x +K ix (∫e x dt) Among them, K px K ix For the position loop PI parameters; (3) Motor control closed-loop operation, obtain encoder feedback ω, and calculate error e. ω : e ω =ω ref -oh e The expression for the PI control output q-axis current command: i qref =K pω ×e ω +K iω (∫e ω dt) Among them, K pω K iω These are the closed-loop PI parameters for motor control. (4) Current closed-loop operation, i is detected by Hall sensor. d i q Calculate the voltage command and generate the PWM wave: u q =K pi ×(i qref -i q )+K ii (∫(i qref -i q )dt) The inverter is driven by SVPWM modulation in the formula; (5) Hydraulic actuation, PMSM drives gear pump to generate flow rate Q p →Actuator cylinder pressure P→Output displacement x, real-time feedback of x, ω, i q A closed loop is formed.

9. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 8, characterized in that, The PI parameter tuning method is as follows: current closed-loop bandwidth > motor control closed-loop bandwidth > position closed-loop bandwidth; current closed-loop response time ≤ 1ms, motor control closed-loop ≤ 5ms, position closed-loop ≤ 20ms; The anti-saturation strategy is set as follows: position closed-loop output limiting: |ω| ref |≤ω max ω max Rated speed of the motor; motor control closed-loop output limit: |i qref |≤i max i max This represents the peak current of the motor. Adding a feedforward term ω to dynamic compensation ref_ff The expression: Where, k hyd Indicates hydraulic gain.

10. The EHA drive and control integrated device based on a three-in-one integrated architecture according to claim 9, characterized in that, The outermost position closed loop is compared with the target position command X. ref With actuator displacement feedback X k The speed command ω is generated by the PI controller. ref This ensures accurate tracking of load displacement. The intermediate layer motor control closed loop receives ω ref The motor speed ω, fed back from the encoder, is used to adjust the output q-axis current command i via a PI controller. qref To stabilize the motor speed and ensure hydraulic power output; The innermost current closed loop is based on i qref and the q-axis current i detected by the Hall sensor q The voltage command u is generated by PI control. q Directly controlling the motor torque serves as the inner loop with a response time of ≤1ms, forming the core foundation for dynamic stability. The three-ring cascade forms a coordinated control chain of "displacement-speed-torque" to achieve precise adjustment from macroscopic position to microscopic current.

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