Flexible control method of multi-motor test bench and test system

Abstract

The invention belongs to the technical field of automobile performance testing, and relates to a flexible control method of a multi-motor test bench and a test system, the flexible control method is applied to the test bench comprising a plurality of independent controllable motor units, and the method comprises the following steps: determining a target test mode based on a test task requirement; determining a corresponding target motor unit participating in work based on the target test mode, activating a corresponding control logic, and executing isolation control on a non-target motor unit which is not determined to participate in work, so as to eliminate or suppress the interference of the non-target motor unit on the cooperative operation of the target motor unit; and based on the activated control logic, taking the real-time state of the target motor unit as feedback, generating a closed-loop control instruction, and driving the target motor unit to cooperatively operate according to a predetermined relationship. Various test requirements can be met, the target motor unit operates independently and reliably, the states of other non-target motor units are not affected, and the authenticity of the test result is ensured.

Description

Technical Field

[0001] This invention belongs to the field of automotive performance testing technology, specifically relating to a flexible control method and testing system for a multi-motor test bench. Background Technology

[0002] With the rapid development of new energy vehicle technology, the demand for performance and reliability testing of powertrains, as the core power source, is increasing. In the process of powertrain research and development, it is necessary to conduct comprehensive and accurate testing and verification of its performance, efficiency, durability and reliability.

[0003] Traditional powertrain test benches often only allow testing of a single type or specific combination of motor units. This "one-to-one" or "fixed combination" testing mode lacks flexibility and struggles to meet the increasingly diverse and platform-based testing needs of the new energy vehicle industry. Furthermore, in real-world scenarios where multiple motors operate simultaneously, traditional test benches face a significant problem: when the test system drives a target motor unit, it generates substantial "coupling interference" or "parasitic effects" on other non-target motor units. This can cause non-target motor units to deviate from their preset static or no-load states, thus affecting the target motor unit's condition. This deviation between the testing environment and real vehicle operating conditions leads to "distorted" test data, reducing its predictive value for actual durability, testing efficiency, and result reliability. Summary of the Invention

[0004] In view of this, the present invention provides a flexible control method and testing system for a multi-motor test bench, which solves the technical problems in the prior art.

[0005] The technical solution of this invention is: A flexible control method for a multi-motor test bench, applied to a test bench containing multiple independently controllable motor units, includes the following steps: Determine the target test mode based on the requirements of the test task; Based on the target test mode, the corresponding target motor unit participating in the work is determined, and the corresponding control logic is activated. For non-target motor units that are not determined to participate in the work, isolation control is executed to eliminate or suppress the interference of the non-target motor units on the cooperative operation of the target motor units. The execution of isolation control includes controlling the non-target motor units to enter and maintain an idle state with zero torque and zero speed, and isolating feedback signals from the non-target motor units in the control loop. Based on the activated control logic, and using the real-time status of the target motor unit as feedback, a closed-loop control command is generated to drive the target motor unit to operate collaboratively according to a predetermined relationship.

[0006] Furthermore, isolating feedback signals from the non-target motor unit in the control loop includes: ignoring or shielding the sensor feedback signals of the non-target motor unit in the software control algorithm, and / or physically cutting off the sensor signal path of the non-target motor unit through a hardware switch.

[0007] Furthermore, the target test mode includes at least one of the following: single motor independent test mode, dual motor towing test mode, multi-motor differential coupling test mode, and multi-motor full-condition simulation test mode.

[0008] Furthermore, the dual-motor towing test mode includes a speed-torque coordinated mode or a torque-speed coordinated mode; the multi-motor differential coupling test mode involves one drive motor unit and at least two load motor units coupled through a differential; the multi-motor full-condition simulation test mode involves the coordinated operation of at least four motor units.

[0009] A testing system, configured to perform the method described above, includes: Multiple independently controllable motor units; The sensing unit is used to measure the operating status parameters of each motor unit in real time; The main controller is communicatively connected to the plurality of motor units and the sensing units, and is configured to execute the flexible control method described above.

[0010] Furthermore, it also includes a flexible hardware platform, on which the motor units are mounted via movable mounting brackets and reconfigurable mechanical interfaces to enable adjustment of the relative positions between the motor units and rapid reconfiguration of the mechanical connections.

[0011] Furthermore, the movable mounting bracket includes: The bracket is fixed to the motor unit; The linear guide rail has a fixed component for connecting to the test bench, and a moving component and a fixed bracket for realizing the linear movement of the motor unit.

[0012] Furthermore, the main controller has a built-in modular software system, which includes: The underlying driver layer provides a hardware abstraction interface to enable data acquisition by the sensing unit and command issuance to the motor unit. The core algorithm layer, connected to the underlying driver layer, encapsulates multiple configurable control logic modules; The application interaction layer, connected to the core algorithm layer, provides a graphical user interface for test mode selection, parameter configuration, real-time monitoring, and data management.

[0013] Furthermore, the multiple control logic modules are as follows: A single-motor control module is used to perform closed-loop control of the speed, torque, or constant power of a single motor unit through a general control chain that includes a rate-of-change limiter, a normal distribution filter, and a PID controller. The dual-motor counter-traction control module is used to establish a coordinated closed loop of speed and torque between two counter-traction motor units, and introduces a dynamic decoupling controller to eliminate coupling interference between motor units. The differential coupling control module is used to establish a main drive closed loop and an independent speed difference closed loop between the first motor unit, which serves as the drive source, and at least two motor units for loading that are mechanically coupled through a differential. The speed difference control submodule precisely adjusts the speed difference between the motor units for loading. The full-condition control module is used to integrate the basic closed-loop control of multiple motor units, and coordinates the differential speed relationship and torque distribution between multiple motors through global coupling management logic to generate collaborative control commands.

[0014] Furthermore, it also includes an adjustable load unit, which is detachably connected to the output shaft of the motor unit.

[0015] Compared with existing technologies, this invention provides a flexible control method and testing system for a multi-motor test bench. The method determines the target test mode based on the test task instructions, realizing intelligent matching between test requirements and system configuration. By activating the corresponding control logic based on the target test mode, the system can automatically adapt to various test scenarios such as single-motor control, dual-motor cooperative control, differential coupling control, and full-condition cooperative control. For non-target motor units that are not determined to participate in the operation, isolation control is executed, effectively eliminating the interference of non-working motor units on the test process and ensuring the purity of the test environment. It effectively solves the comprehensive defects of low accuracy of multi-motor cooperation and interference of non-working motor units on the authenticity of the test in existing technologies. It can meet a variety of test requirements and achieve full coverage from single-motor independent testing to multi-motor full-condition testing, significantly improving test efficiency and result reliability. It is highly practical and worthy of promotion. Attached Figure Description

[0016] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0017] This invention provides a flexible control method and testing system for a multi-motor test bench to solve the above-mentioned problems. In order to enable those skilled in the art to better understand the technical solution of this invention and implement it, the technical solution of this invention will be clearly and thoroughly described below with reference to the accompanying drawings.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] Furthermore, it should be further explained that in the description of the embodiments of the present invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" means two or more.

[0020] The terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only and do not represent the only possible implementation.

[0024] Example 1 This invention proposes a flexible control method for a multi-motor test bench, such as... Figure 1 As shown, the specific implementation steps include the following: Step 1: Determine the target test mode based on the test task requirements.

[0025] Test task requirements refer to structured instructions input from the host computer operation interface or issued by an external test management system. The content should include at least the type of the object under test, such as single motor independent test mode, dual motor towing test mode, multi-motor differential coupling test mode, or multi-motor full-condition simulation test mode, test objectives, such as efficiency MAP plotting, differential response time measurement, NEDC condition cycle simulation, and key parameter constraints such as maximum speed ≤15000 rpm, maximum torque ≥800 N·m, and sampling frequency ≥1 kHz.

[0026] The instructions for issuing test tasks are parsed by the application interaction layer and converted into standardized pattern identifiers. These pattern identifiers serve as the core scheduling basis, driving subsequent resource configuration and algorithm loading processes. This step does not rely on fixed physical configurations and supports rapid switching of test modes through software definition.

[0027] Step 2: Based on the target test mode, determine the target motor unit to participate in the work and activate the corresponding control logic. For non-target motor units that are not determined to participate in the work, execute isolation control to eliminate or suppress the interference of the non-target motor units on the cooperative operation of the target motor units.

[0028] Here, the target motor unit refers to the set of motor units assigned an active control role under the current standardized mode identifier. For example, in the dual-motor counter-drive test mode, the target motor units are fixed as M1 on the drive end and M2 on the load end. In the multi-motor full-condition simulation test mode, it is all five motor units, M1–M5. The process of determining the corresponding target motor units to participate in the work is implemented by the main controller based on the identifier function unit pre-encapsulated in the core algorithm layer based on the identifier array. Non-target motor units refer to the remaining motor units that do not appear in the current target motor unit identifier array.

[0029] Specifically, performing isolation control includes controlling the non-target motor unit to enter and maintain an idle state with zero torque and zero speed, and isolating feedback signals from the non-target motor unit in the control loop.

[0030] As a preferred solution for implementing isolation control, the system may include a multiplexer. When the motor unit is marked as idle, the main controller controls the multiplexer to physically cut off the path of its speed and torque sensor signals to the main controller, thus preventing feedback signals from entering at the hardware level.

[0031] Specifically, isolating feedback signals from non-target motor units in the control loop includes: ignoring or shielding the sensor feedback signals of the non-target motor units in the software control algorithm, and / or physically cutting off the sensor signal path of the non-target motor units through hardware switches.

[0032] In practice, entering the idle state includes the following methods: First, the main controller sends a standardized zero command to the motor unit controller of the corresponding non-target motor unit via the bus. This command includes a zero speed setting (0 rpm) or a zero torque setting (0 N·m).

[0033] Second, after receiving the standardized zero command, the motor unit controller of the non-target motor unit drives the power device to enter the low-resistance braking state or the high-resistance free stop state, ensuring that the motor unit shaft system stops rotating within a preset time and the absolute value of the residual torque is ≤0.1 N·m.

[0034] Third, in the core algorithm layer, the feedback data streams of the speed sensor and torque sensor of the non-target motor unit are marked as invalid through the feedback shielding interface of the underlying drive layer, so that all upper-level control algorithms can skip the data reading of the feedback channel of the non-target motor unit and participate in the calculation during the operation.

[0035] The above-mentioned methods work together to form a hardware-software co-isolation system, specifically manifested in: cutting off energy input at the electrical level, suppressing shaft inertial motion at the mechanical level, and eliminating signal contamination at the software level.

[0036] In specific implementation, when the main controller detects that the actual speed of the non-target motor unit exceeds 3 rpm for 50 ms, the main controller triggers the secondary protection and sends a brake command to the motor unit controller of the non-target motor unit, or uses FPGA hardware logic to implement physical channel shutdown before the sensor signal enters the MCU, so as to achieve nanosecond-level feedback isolation.

[0037] Step 3: Based on the activated control logic, and using the real-time status of the target motor unit as feedback, generate closed-loop control commands to drive the target motor unit to operate collaboratively according to a predetermined relationship.

[0038] Here, the real-time status of the target motor unit refers to the effective feedback quantity collected and calibrated by the sensing unit. This effective feedback quantity includes, but is not limited to: the instantaneous speed of the output shaft of each motor unit (unit: rpm, resolution: 0.01 rpm) and the measured torque at the coupling (unit: N·m, accuracy: ±0.2% FS). All feedback data are accompanied by precise timestamps (synchronization error ≤1 μs) and are supplied to the core algorithm layer through the underlying drive layer.

[0039] Closed-loop control commands refer to the final control quantities output by the control logic module and applied to the motor unit controller of the target motor unit. Their form varies depending on the mode: in single-motor mode, it is a speed / torque command output by a single PID regulator. In dual-motor driven mode, it is a decoupled dual-channel command (M1 outputs speed command + M2 outputs torque command). In differential coupling mode, it includes a main drive command (applied to M1) and a speed difference compensation command (superimposed on M2 and M3 respectively). In full-condition mode, it is a five-dimensional vector command set. All commands are constrained by a rate-of-change limiter to prevent abrupt changes and suppress high-frequency noise through a normal distribution filter.

[0040] Here, the predetermined relationship is a physical constraint relationship determined by the nature of the test mode. This step ensures that the control closed loop is fully focused on the real test object by strictly limiting the feedback signal to the target motor unit and performing relationship calculation by a dedicated control logic module, thus avoiding model mismatch and delay disturbances introduced by non-target units.

[0041] Through the synergy of the above steps, this invention achieves a dynamic mapping across the entire chain, from test task to mode selection, motor unit role allocation, and control closed-loop construction. Because the test task requires direct identification and confirmation of the target test mode, it can overcome the dependence on fixed mechanical configurations and hard-coded logic, supporting a full spectrum of test scenarios from single-machine to system-wide levels on the same hardware platform. Since the target test mode precisely defines the set of target motor units participating in the operation and synchronously activates the strictly matched control logic modules, it ensures the consistency between the control algorithm and the physical object, avoiding control instability caused by module misloading. By implementing forced static constraints of zero torque / zero speed on non-target motor units and performing dual processing of software shielding and hardware isolation on their sensor feedback signals in the control loop, parasitic vibrations, electromagnetic interference, and signal crosstalk generated by non-working motor units are completely eliminated, ensuring the purity of the test environment and the authenticity of the data. Because the generation of closed-loop control commands is based entirely on the real-time effective feedback of the target motor unit and the predetermined physical relationship is solved by a dedicated control logic module, high-precision and robust collaborative operation of multiple motors under complex coupling constraints is achieved. This method is not limited to a specific number or model of motor units and can be applied to various types such as permanent magnet synchronous motor units, induction motor units, and switched reluctance motor units. It can also be extended to composite test systems that include hybrid power sources such as hydraulic loading units and inertia simulation units.

[0042] As a further explanation of the above embodiments, the target test mode includes at least one of the following: single motor independent test mode, dual motor drag test mode, multi-motor differential coupling test mode, and multi-motor full-condition simulation test mode.

[0043] Here, the target test mode refers to a standardized test configuration set according to the current test task, with clear physical connection relationships, control objectives and collaborative logic. In essence, it maps test requirements into a combination of executable hardware configuration instructions and software algorithm loading instructions, which constitute the upper-level logic entry point of the flexible control method.

[0044] Each mode corresponds to a set of preset motor unit participation identifiers, mechanical interface configuration rules, sensor feedback channel enable strategies, and core control logic module activation paths. During the system initialization phase, the main controller completes the entire process guidance from physical connection prompts and sensor channel configuration to control algorithm loading by parsing the mode identifier in the test task instructions, thereby achieving flexible adaptation capabilities of one platform, multiple modes, and zero-code switching.

[0045] The single-motor independent test mode refers to a benchmark verification configuration where only one motor unit is used as the test object, and all other motor units are in idle management mode. In this mode, the motor unit under test is directly connected to an adjustable load unit, such as an eddy current dynamometer or a magnetic powder brake, via a flexible diaphragm coupling to conduct basic performance tests such as speed closed-loop, torque closed-loop, or constant power operation. In the single-motor independent test mode, the control objective is singular and the feedback path is clear. It is suitable for motor unit parameter calibration, driver response characteristic evaluation, and control algorithm benchmark verification. It does not rely on the coordinated action of other motor units, but requires strict signal isolation and zero-command maintenance for non-participating motor units (such as M2–M5) in the idle management mode to avoid electromagnetic noise from their free rotation interfering with the speed encoder signal, or residual magnetic field disturbance causing zero-point drift in the torque sensor.

[0046] Among them, the dual-motor counter-drive test mode refers to two motor units directly connected by a rigid coupling or a high-rigidity diaphragm coupling, serving as the drive end and the loading end respectively, forming a dynamic interactive verification configuration of a power self-circulation loop. In this mode, the drive motor unit outputs mechanical energy, and the loading motor unit absorbs and converts it into heat energy or feeds it back to the grid. It can simulate the energy exchange process under real working conditions without the need for external load equipment. Its control logic is divided into two sub-modes: speed-torque coordination mode (i.e., the drive motor unit runs according to the set speed curve, and the loading motor unit outputs according to the set torque curve) and torque-speed coordination mode (i.e., the loading motor unit runs according to the set torque curve, and the drive motor unit outputs according to the set speed curve). Both sub-modes can be switched with a single click via the mode management module of the main controller, and PID parameter groups, feedforward compensation coefficients, and rate of change limit thresholds can be configured. The typical physical implementation of this mode includes: motor unit M1 and motor unit M2 are directly connected via a precision coupling supported by double-row angular contact ball bearings, with strain gauge torque sensors connected in series to monitor the transmitted torque in real time. Incremental encoders with a resolution of 20000 PPR are installed on the output shafts of both motor units M1 and M2 for speed feedback. To suppress coupled oscillations caused by mechanical backlash, shaft torsional vibration, and current harmonics during the towing process, a dynamic decoupling controller is embedded in the dual-motor towing collaborative control logic module. Its input is the measured speed and torque deviation of the two motor units, and its output is an additional compensation torque command, which is synchronously sent to the corresponding motor unit driver via the bus.

[0047] The multi-motor differential coupling test mode refers to a test configuration with three or more degrees of freedom, consisting of one drive motor unit coupled to at least two load motor units via a mechanical differential. This configuration is used to verify the complex coupling characteristics of new energy vehicle four-wheel drive systems, wheel-side motor unit differential coordination, and dynamic distribution of electric drive axles. In a typical implementation, the drive motor unit (e.g., M1) is connected to the power input end of the differential via a coupling, and the two load motor units (e.g., M2, M3) are connected to the left and right output half-shafts of the differential, respectively, thus establishing a "one-drive, two-load" power topology.

[0048] The multi-motor full-condition simulation test mode refers to at least four motor units operating collaboratively under unified timing constraints to simulate the dynamic behavior of different functional units in the vehicle's powertrain system. In this mode, the motor units do not simply operate in parallel, but rather maintain the authenticity of the control loop by assigning roles and coordinating commands based on global coupling management logic.

[0049] A testing system includes multiple independently controllable motor units, a sensing unit for real-time measurement of the operating status parameters of each motor unit, and a main controller. The main controller is communicatively connected to the multiple motor units and the sensing unit, and is configured to execute the flexible control method described above.

[0050] As a further optimization of this embodiment, a flexible hardware platform is also included. The motor unit is mounted on the flexible hardware platform through a movable mounting bracket and a reconfigurable mechanical interface to realize the adjustment of the relative position between the motor units and the rapid reconfiguration of the mechanical connection.

[0051] Among them, the movable mounting bracket refers to the bracket body being rigidly fixed to the motor unit, while the bracket base is mounted on a linear guide rail or rotary positioning platform, so that the center distance between the output shafts of adjacent motor units can be continuously adjusted within the range of 200 mm to 700 mm to adapt to the installation requirements of couplings or differentials of different lengths.

[0052] Based on the above embodiments, this embodiment is further refined. Specifically, the movable mounting bracket includes a bracket fixed to the motor unit, the bracket is fixed to the movable part of the linear guide rail, the fixed part of the linear guide rail is used to connect to the test bench, and the linear guide rail is used to realize the linear movement of the motor unit.

[0053] The movable mounting bracket is a key structural unit for the flexible hardware platform to achieve physical reconfiguration capabilities. Its core lies in supporting the rapid, accurate, and resettable adjustment of the center distance between motor units under different testing modes through a standardized, highly repeatable linear motion mechanism. This structure does not rely on special tooling or temporary pads, avoiding coaxiality deviations and installation stress caused by manual adjustment. It provides a stable and reliable mechanical foundation for the alignment of couplings between multiple motors, the coupling of differential input / output shafts, and the adaptation connection of adjustable load units.

[0054] The bracket, serving as the load-bearing structure, is rigidly connected directly to the motor unit housing or base flange. Its structure consists of a reinforced cast iron or aluminum alloy frame with a standardized array of threaded holes to accommodate the mounting hole spacing of different motor unit models. The bottom of the bracket has a mounting interface that matches the linear guide rail moving parts. This interface uses T-slots or countersunk bolt holes with anti-loosening washers to ensure no relative slippage during long-term operation.

[0055] The linear guide rail forms the main guiding and load-bearing component. Its fixing components are rigidly connected to the test bench base via high-strength bolts, while the moving components are fastened to the bottom of the support with bolts, forming a three-stage force transmission path of "fixed-sliding-load-bearing". The guide rail body adopts a precision-ground ball linear guide rail with a rated dynamic load of not less than 15 kN, a repeatability accuracy better than ±0.01 mm, and a travel range of 500 mm to 1200 mm, which is sufficient to meet all typical configuration requirements such as single-motor testing (short-distance coupling), dual-motor drag (medium-distance direct connection), three-motor unit differential coupling (long-distance differential installation), and five-motor unit full-condition layout (multi-segment staggered arrangement).

[0056] This invention utilizes a movable mounting bracket to achieve continuous, precise, and resettable adjustment of the center distance between any two adjacent motor units within a range of 200 mm to 700 mm, without disassembling the motor unit body or replacing mechanical connectors, simply by adjusting the position of the bracket on the linear guide. Because the bracket is rigidly fixed to the motor unit, and the linear guide provides high-precision single-degree-of-freedom guidance, it avoids shaft misalignment and additional bending moments caused by traditional shim adjustments. Because the moving part is integrally and securely fastened to the bracket, it eliminates relative displacement caused by vibration or sudden load changes after adjustment. Because the guide travel covers the distance required for all typical test configurations, it can adapt to various modes such as single motor, dual motor, differential coupling, and all operating conditions without replacing the bracket or guide—thus solving the problem of "poor flexibility" in the prior art. This provides a structural foundation for the "movable mounting bracket" and "reconfigurable mechanical interface" in this invention that can be implemented in engineering, verified in batches, and operated stably for a long time.

[0057] Reconfigurable mechanical interfaces include, but are not limited to, quick-release flanges, modular couplings (including diaphragm type, universal joint type, and rigid short-joint type), differential standard mounting bases, and shaft end mating sleeves with radial locking mechanisms. Their common feature is that the mechanical connection method can be changed without tools or with only a simple wrench, and the repeatability is better than ±0.1 mm.

[0058] As a further explanation of this embodiment, the sensing unit includes a speed sensor and a torque sensor. The speed sensor installed on the output shaft of each motor unit can be an incremental photoelectric encoder, a magnetoelectric rotary transformer, or a high-resolution Hall switch array. Its installation position is strictly limited to the output flange side or shaft extension end of the motor unit to avoid signal attenuation after transmission through the coupling. The torque sensor connected to the coupling refers to a series dynamic torque sensor. Its body is embedded between the two drive shafts, and its two ends are respectively bolted to the flange of the drive side and the load side coupling. The measurement range covers ±50 N·m to ±2000 N·m, and the sampling bandwidth is not less than 3 kHz to capture transient torque fluctuations.

[0059] The main controller has a built-in modular software system. Based on the selected test mode, the modular software system selectively controls some motor units to work together in a predetermined relationship, while controlling the remaining motor units to enter an idle isolation state.

[0060] Based on the above embodiments, this embodiment further refines the scheme. The modular software system includes a bottom driver layer, a core algorithm layer, and an application interaction layer.

[0061] The underlying driver layer provides a hardware abstraction interface to enable data acquisition from the sensing unit and command issuance to the motor unit. It serves as the hardware access hub for the entire software system. Its core function is to shield the differences in underlying hardware and provide a unified, stable, and verifiable hardware abstraction interface. This layer directly interfaces with various physical sensors and actuators.

[0062] The core algorithm layer is connected to the underlying driver layer and encapsulates multiple configurable control logic modules. It is the intelligent hub of the software system. Its function is to integrate four types of control logic modules in a loosely coupled and pluggable manner into a unified operating framework. This layer does not directly operate the hardware, but obtains status data by calling the HAL interface provided by the underlying driver layer and outputs standardized control commands.

[0063] The application interaction layer provides a graphical user interface for test mode selection, parameter configuration, real-time monitoring and data management. It serves as a bridge between the system and the user. Essentially, it is a cross-platform human-computer interaction service framework that establishes a bidirectional connection with the main controller through standard industrial communication protocols, receives underlying status data and pushes user commands.

[0064] The modular software system adopts the aforementioned three-layer architecture design. Through separation of responsibilities and interface standardization, it solves the problems of poor maintainability, high upgrade costs, and difficult cross-platform adaptation caused by loose software structure, high hardware coupling, difficulty in algorithm reuse, and fragmented human-computer interaction in existing testing systems. This architecture does not depend on a specific controller model or communication protocol and supports deployment on different main controllers, providing a solid software foundation for the long-term evolution and functional expansion of multi-motor flexible test benches.

[0065] Based on the above embodiments, as a further explanation of this embodiment, the multiple control logic modules are as follows: The single-motor control module is used to perform closed-loop control of the speed, torque, or constant power of a single motor unit through a general control chain including a rate-of-change limiter, a normal distribution filter, and a PID controller. The dual-motor counter-drive cooperative control logic module is used to establish a cooperative closed loop of speed and torque between two counter-drive motor units and introduces a dynamic decoupling controller to eliminate coupling interference between motor units. The differential coupling control module is used to establish a main drive closed loop and an independent speed difference closed loop between the first motor unit, which serves as the drive source, and at least two motor units mechanically coupled through differentials for loading. The speed difference control submodule precisely adjusts the speed difference between the motor units for loading. The full-condition cooperative control logic module is used to integrate the basic closed-loop control of multiple motor units and coordinate the differential relationship and torque distribution between multiple motors through global coupling management logic to generate cooperative control commands.

[0066] The existence of multiple control logic modules is to address the differences in physical coupling mechanisms and control objectives under different test modes. Each module has clearly defined structural characteristics, functional boundaries, and algorithmic logic, ensuring the modular software system possesses verifiable, reproducible, and replaceable technical qualities. Each module is deployed within the core algorithm layer of the main controller's modular software system, existing as an independent, loadable software functional block. It supports dynamic loading and unloading at runtime and interacts with each other through standardized data interfaces, without sharing internal variables or directly calling each other's private functions.

[0067] The single-motor control module adopts a three-stage series universal regulation chain of "rate of change limiter - normal distribution filter - PID controller", which can be adapted to three working modes: speed closed loop, torque closed loop and constant power closed loop, taking into account both fast response and disturbance rejection robustness: the rate of change limiter acts on the set value input terminal to constrain the change slope of the speed / torque command to not exceed the preset threshold (500 rpm / s or 20 N·m / ms), preventing mechanical shock or current overshoot caused by step command. The normal distribution filter is a one-dimensional sliding window weighted average filter based on a Gaussian kernel. Its window width is configurable (16–64 sampling points) and is used to suppress high-frequency jitter caused by encoder quantization noise and torque sensor zero drift. Compared with traditional mean filtering or first-order inertial filtering, it has less phase lag in step response. The PID controller performs proportional-integral-derivative operations based on the deviation signal after preprocessing. Its parameters (Kp / Ki / Kd) can be tuned online according to the operating conditions. For example, in constant power mode, Ki automatically decays to avoid integral saturation, while Kp is enhanced to improve stiffness in the low-speed, high-torque region.

[0068] The dual-motor cooperative control logic module establishes a two-way cooperative closed loop. Its cooperative relationship can be configured in two paradigms: "speed-torque" or "torque-speed." The former uses the drive motor unit's speed as a reference, with the load motor unit's output torque tracking the resistance torque generated by the speed deviation through a mapping function (such as a lookup table or polynomial fitting). The latter uses the load motor unit's torque as a reference, with the drive motor unit's speed response derived from the torque command through a dynamic inverse model to obtain the target vehicle speed. The dynamic decoupling controller directly addresses the problem of "complex coupling effects caused by mechanical connections and electromagnetic interference in multi-motor coupling tests" in the background technology, avoiding the following lag and oscillations caused by traditional unidirectional master-slave control. In practical applications, a neural network dynamic decoupler can be used instead of a linear model decoupler, or an online recursive least squares algorithm can be used to update the decoupling matrix in real time when only some coupling parameters are known.

[0069] The differential coupling control module adopts a master-slave dual-loop nested structure. The outer loop is the master drive closed loop, with the speed of the first motor unit (drive source) as the controlled variable. The reference value is set by the test task, and the controller outputs the target torque of the drive motor unit. The inner loop is the speed difference closed loop, with the actual speed difference between the motor unit M1 and motor unit M2 used for loading as the controlled variable. The reference value is given by the differential coupling test requirements (simulating the speed difference between the inner and outer wheels when the vehicle is turning). Its controller output is an additional torque compensation amount, which is superimposed on the local torque commands of the motor units M1 and M2 used for loading. The speed difference control submodule is the inner loop controller, which adopts a PI structure with derivative-first, automatically injecting a small reverse torque disturbance to overcome the static friction dead zone. This dual-loop design separates the system-level drive task from the local differential adjustment task, ensuring that the master drive response is not disturbed by the differential adjustment process, while achieving independent optimization of differential accuracy.

[0070] The full-condition collaborative control logic module embodies a system-level coordination architecture: its underlying layer still calls the existing single-motor control modules of each motor unit to complete the basic closed loop (i.e., each motor unit runs its own PID + feedforward chain), while the upper layer redistributes and reconstrains multi-motor commands through global coupling management logic. This logic receives global commands from the test task, parses them into the initial command set of each motor unit, and then starts the coupling constraint solver based on the real-time feedback coupling state—this solver aims to minimize the multi-motor command adjustment amount, satisfying multiple inequality constraints such as torque distribution ratio, speed synchronization tolerance, and power balance, and outputs the final collaborative command.

[0071] The four control logic modules are differentiated in terms of physical connection, signal flow, and control objectives: the single-motor module targets isolated units, emphasizing individual stability; the dual-motor module targets paired, strongly coupled units, emphasizing bidirectional dynamic matching; the differential coupling module targets mechanically hard-connected multi-body subsystems (drive + differential + loading group), emphasizing master-slave decoupling and precise differential values; and the full-condition module targets the global topology, emphasizing system optimization under multiple constraints. They share the same underlying drive layer and sensing unit, but data flow within the core algorithm layer is strictly isolated—when any module runs, it only subscribes to the sensor channels it needs and does not access intermediate variables of other modules, ensuring module independence and fault isolation.

[0072] Each control logic module is bound to a unique algorithm package. For example, the single-motor independent test mode calls the single-motor control module, and the dual-motor towing test mode calls the dual-motor towing collaborative control logic module. The two are completely decoupled at the code level and do not call each other's internal functions. When the main controller selectively controls some motor units, it sends enable signals and control instructions to the servo drivers of the specified motor units through the hardware abstraction layer, and at the same time sends disable instructions and zero setpoints to the drivers of other motor units. The idle isolation state not only means that the motor unit stops rotating, but also includes cutting off the data path of its feedback signal to the core control algorithm at the software level. That is, in the signal preprocessing stage before PID calculation, the measured speed / torque values ​​of the idle motor units are set as invalid to prevent them from participating in any weighted calculation or cross-coupling compensation.

[0073] Taking the dual-motor towing test mode as an example: After the operator selects this mode, the main controller automatically loads the dual-motor counter-drive collaborative control logic module and identifies the drive-end motor unit M1 and the load-end motor unit M2 as participating units based on the current physical connection status. Simultaneously, the system drives the movable bracket to adjust the axes of the drive-end motor unit M1 and the load-end motor unit M2 to a coaxiality of ≤0.05mm. The elastic diaphragm coupling is then connected via a quick-release flange. Speed ​​sensors collect the output shaft angular velocities of the drive-end motor unit M1 and the load-end motor unit M2 in real time, while torque sensors synchronously acquire the torque transmitted by the coupling. The main controller generates closed-loop commands based on the speed-torque collaborative algorithm, driving the drive-end motor unit M1 to operate according to the target speed curve, while the load-end motor unit M2 tracks and matches the required load torque in real time. Meanwhile, motor units M3, M4, and M5 are marked as idle. Their corresponding drivers receive zero-speed commands and enter a high-damping free-stop state, and their encoder feedback signals are logically masked in the software and do not participate in any control calculations. Because the mechanical movement of motor units M3, M4, and M5 is suppressed and the electrical feedback is isolated, the parasitic interference on the test circuit of motor unit M1 at the drive end and motor unit M2 at the load end is significantly reduced. This solves the problem of the authenticity of interference testing of motor units in non-working state in the background technology. The support of movable bracket and reconfigurable interface allows the same set of hardware to be switched to the three-motor unit differential mode without disassembly or modification. Only motor units M2 and M3 need to be moved to the differential input end, and motor unit M1 at the drive end is connected to the other input end of the differential as the drive source. Motor units M4 and M5 remain idle. This breaks through the technical limitations of traditional bench functions being fixed and reconfiguration cycles being long.

[0074] Through the above technical solutions, this invention enables the modular software system to be endowed with differentiated, verifiable and reproducible features on the basis of a flexible hardware platform, so that the same test system can adapt to the full spectrum of test requirements from single motor characteristic calibration to vehicle-level powertrain integration verification without changing the hardware.

[0075] Based on the above embodiments, this embodiment further refines the scheme. The modular software system also includes a data acquisition and storage unit. This unit is configured to synchronously acquire data and control commands from the speed sensor and torque sensor at a frequency of 1kHz to 1.5kHz, and store them with timestamps. The frequency of 1kHz to 1.5kHz means that the main clock cycle for this unit to perform the sampling task is strictly limited to the range of 667μs to 1000μs. The lower limit of the sampling rate satisfies the Nyquist-Shannon sampling theorem requirement for the dynamic process of the motor unit, while the upper limit balances real-time processing capability and storage bandwidth constraints. This ensures that analog-to-digital conversion and cache writing are completed under the same hardware trigger signal, guaranteeing millisecond-level or even sub-millisecond-level time alignment and eliminating phase shifts caused by multi-source asynchronous reading. Timestamped storage means that each frame of acquired data is marked with an absolute time stamp by a high-precision hardware real-time clock before being written to non-volatile storage media. The timestamp is atomically bound to the data frame and is indivisible. The hardware-level timestamp assigns each set of data a unique, comparable, and traceable spatiotemporal coordinate, providing a foundation for subsequent analysis or tracing.

[0076] Through the above technical solutions, the present invention realizes the clear structure, professional responsibilities and standardized interfaces of modular software systems, and provides a stable, reliable and evolvable software support foundation.

[0077] The core of this testing system lies in constructing a three-tiered collaborative architecture of "physical layer—perception layer—decision layer." A flexible hardware platform forms the variable physical foundation, supporting rapid switching of mechanical configurations required for different testing modes. Sensing units constitute the state-aware base, ensuring that key dynamic parameters are observable, measurable, and traceable. The main controller and its modular software system form the intelligent decision-making center, enabling on-demand loading of control strategies, dynamic resource scheduling, and precise generation of closed-loop commands. Specifically, the multiple independently controllable motor units in the flexible hardware platform refer to no fewer than two, and optionally five, servo motor units. Each motor unit possesses independent position / speed / torque three-loop control capabilities, and their electrical interfaces and communication protocols are mutually compatible, allowing them to be connected to the same main controller management domain.

[0078] A clear hierarchical dependency and functional mapping relationship is formed among the above-mentioned technical features: The movable mounting bracket and reconfigurable mechanical interface together determine the physical adaptation boundary of the flexible hardware platform, which is a prerequisite for realizing mechanical connections in different test modes. The spatial arrangement and type selection of speed and torque sensors directly constrain the accuracy and bandwidth of state feedback, thus affecting the dynamic response capability of closed-loop control. Meanwhile, the encapsulation granularity and interface specifications of each control logic module in the modular software system determine whether the main controller can complete mode switching and algorithm loading within milliseconds, ensuring the real-time performance and determinism of selective control and idle isolation. The synergistic effect of these three elements enables the system to focus on local performance verification in single-motor testing and maintain global coordination and consistency in multi-motor coupled scenarios. Through the above technical solutions, this invention achieves a complete system-level implementation of the flexible control method of this invention.

[0079] Based on the above embodiments, this embodiment is further optimized, specifically including an adjustable load unit that is detachably connected to the output shaft of the motor unit.

[0080] An adjustable load unit refers to an electromechanical device that can dynamically adjust the characteristics of the applied load according to control commands. Its core function is to simulate the resistance characteristics under real working conditions, rather than just providing fixed damping. This unit includes, but is not limited to: eddy current dynamometer, magnetic powder brake, AC electric dynamometer and hydraulic loading system.

[0081] The detachable connection structure ensures quick, accurate, and repeatable docking between the output shaft of the motor unit used for loading and the input shaft of the adjustable load unit. The motor unit used for loading acts as an active execution node, serving as the test object in the single-motor independent test mode and as a controlled load in the dual-motor drag or differential coupling test mode. The adjustable load unit outputs load torque matching the target working condition in real time according to the closed-loop command generated by the main controller.

[0082] The introduction of the adjustable load unit enables this invention to break through the limitations of traditional no-load or fixed resistance loads, covering constant torque, constant speed, constant power, dynamic step, sinusoidal frequency sweep and any load spectrum based on actual vehicle conditions, thus ensuring the completeness of single motor testing without sacrificing the overall reconfigurability of the system.

[0083] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A flexible control method for a multi-motor test bench, characterized in that, Includes the following steps: Determine the target test mode based on the requirements of the test task; Based on the target test mode, the corresponding target motor unit participating in the work is determined, and the corresponding control logic is activated. For non-target motor units that are not determined to participate in the work, isolation control is executed to eliminate or suppress the interference of the non-target motor units on the cooperative operation of the target motor units. The execution of isolation control includes controlling the non-target motor units to enter and maintain an idle state with zero torque and zero speed, and isolating feedback signals from the non-target motor units in the control loop. Based on the activated control logic, and using the real-time status of the target motor unit as feedback, a closed-loop control command is generated to drive the target motor unit to operate collaboratively according to a predetermined relationship.

2. The flexible control method for a multi-motor test bench according to claim 1, characterized in that, Isolating feedback signals from the non-target motor unit in the control loop includes: ignoring or masking the sensor feedback signals of the non-target motor unit in the software control algorithm, and / or physically cutting off the sensor signal path of the non-target motor unit through a hardware switch.

3. The flexible control method for a multi-motor test bench according to claim 2, characterized in that, The target test mode includes at least one of the following: single motor independent test mode, dual motor drag test mode, multi-motor differential coupling test mode, and multi-motor full-condition simulation test mode.

4. The flexible control method for a multi-motor test bench according to claim 3, characterized in that, The dual-motor drag test mode includes a speed-torque coordinated mode or a torque-speed coordinated mode; the multi-motor differential coupling test mode involves one drive motor unit and at least two load motor units coupled through a differential; the multi-motor full-condition simulation test mode involves the coordinated operation of at least four motor units.

5. A testing system, characterized in that, include: Multiple independently controllable motor units; The sensing unit is used to measure the operating status parameters of each motor unit in real time; A main controller is communicatively connected to the plurality of motor units and the sensing units, and the main controller is configured to perform the flexible control method as described in any one of claims 1-4.

6. The testing system according to claim 5, characterized in that, It also includes a flexible hardware platform, on which the motor units are mounted via movable mounting brackets and reconfigurable mechanical interfaces to enable adjustment of the relative positions between the motor units and rapid reconfiguration of the mechanical connections.

7. The testing system according to claim 6, characterized in that, The movable mounting bracket includes: The bracket is fixed to the motor unit; The linear guide rail has a fixed component for connecting to the test bench, and a moving component and a fixed bracket for realizing the linear movement of the motor unit.

8. The testing system according to claim 7, characterized in that, The main controller has a built-in modular software system, which includes: The underlying driver layer provides a hardware abstraction interface to enable data acquisition by the sensing unit and command issuance to the motor unit. The core algorithm layer, connected to the underlying driver layer, encapsulates multiple configurable control logic modules; The application interaction layer, connected to the core algorithm layer, provides a graphical user interface for test mode selection, parameter configuration, real-time monitoring, and data management.

9. The testing system according to claim 8, characterized in that, The multiple control logic modules are as follows: A single-motor control module is used to perform closed-loop control of the speed, torque, or constant power of a single motor unit through a general control chain that includes a rate-of-change limiter, a normal distribution filter, and a PID controller. The dual-motor counter-traction control module is used to establish a coordinated closed loop of speed and torque between two counter-traction motor units, and introduces a dynamic decoupling controller to eliminate coupling interference between motor units. The differential coupling control module is used to establish a main drive closed loop and an independent speed difference closed loop between the first motor unit, which serves as the drive source, and at least two motor units for loading that are mechanically coupled through a differential. The speed difference control submodule precisely adjusts the speed difference between the motor units for loading. The full-condition control module is used to integrate the basic closed-loop control of multiple motor units, and coordinates the differential speed relationship and torque distribution between multiple motors through global coupling management logic to generate collaborative control commands.

10. The testing system according to claim 7, characterized in that, It also includes an adjustable load unit, which is detachably connected to the output shaft of the motor unit.

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