Adaptive torque distribution synchronous control method and system for double-input single-output motor merging system
Patent Information
- Application Number
- CN202611157327.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-31
- Publication Date
- 2026-10-13
AI Technical Summary
一类方法仅依据位置误差或速度误差实施同步补偿，然而在刚性或半刚性机械耦合系统中，两电机转速可能因结构约束而呈现表观一致，但实际输出转矩却严重不均，速度同步并不能等同于转矩均衡；另一类方法引入两支路转矩差作为控制依据，但仅关注两输入支路转矩是否接近，并未进一步判断其是否有效传递至公共输出端，当传动机构出现摩擦突变、齿隙冲击、弹性变形或传动效率波动时，两支路转矩差无法反映输入侧与输出侧之间的真实动力传递状态；此外，固定比例分配策略难以适应运行过程中电流裕量、热负荷及支路效率的动态变化，易造成单侧电机长期过载
[0030]从以上技术方案可以看出，本申请具有以下优点：通过同时引入同步误差、转矩均衡误差和输入-输出三转矩闭合残差三个维度的评价指标，实现了对系统运动同步性、转矩均衡性和输入输出能量一致性的一体化综合感知。基于输入-输出三转矩闭合残差生成的扰动补偿量，能够有效抑制外部负载突变、内部参数摄动和未建模动态等不确定性因素对系统的影响，提升系统的鲁棒性和抗干扰能力。通过转矩均衡误差、三转矩闭合残差及电机负荷状态共同驱动自适应转矩分配系数的在线更新，能够根据两台电机的实时负荷能力和运行工况动态优化转矩分配策略，避免单台电机过载，延长设备使用寿命。同步补偿量的生成融合了同步误差、转矩均衡误差和三转矩闭合残差的多重反馈信息，实现了运动同步控制与转矩均衡控制的协调统一，有效降低双电机汇流系统的扭转振动和功率循环损耗，提高汇流效率及输出端的运动平稳性。
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Abstract
Description
Technical Field
[0001] This application relates to the field of motor cooperative control technology, specifically to an adaptive torque distribution synchronous control method and system for a dual-input single-output motor bus system. Background Technology
[0002] The dual-motor combined drive structure, by coupling the power of two active motors to a common output terminal, offers significant advantages over single-motor drives in heavy-duty equipment, test benches, vehicles, and precision industrial transmissions, including larger power capacity, smaller single-motor load, and stronger redundancy and reliability. However, in actual engineering, due to the combined effects of multiple factors such as differences in motor parameters, non-uniform transmission stiffness, time-varying friction characteristics, assembly gaps, temperature rise, and external disturbances, even if the two motors receive exactly the same commands, their actual output torque is difficult to balance. This leads to a series of problems such as single-motor overload, transmission shock, torsional vibration, output speed fluctuations, and reduced fatigue life of components.
[0003] Existing synchronous control schemes mainly include master-slave control, cross-coupling control, electronic gears, and torque difference feedback, but all have inherent limitations. One type of method only relies on position or speed error for synchronous compensation. However, in rigid or semi-rigid mechanical coupling systems, the speeds of the two motors may appear to be the same due to structural constraints, but the actual output torques are severely uneven, and speed synchronization is not equivalent to torque balance. Another type of method introduces the torque difference between the two branches as a control basis, but only focuses on whether the torques of the two input branches are close, without further determining whether they are effectively transmitted to the common output. When the transmission mechanism experiences sudden friction changes, backlash impact, elastic deformation, or transmission efficiency fluctuations, the torque difference between the two branches cannot reflect the true power transmission state between the input and output sides. In addition, fixed ratio allocation strategies are difficult to adapt to the dynamic changes in current margin, thermal load, and branch efficiency during operation, which can easily cause long-term overload of one side of the motor.
[0004] Therefore, a dual-input motor cooperative synchronization control method needs to be proposed to enable the synchronization of the position and speed of the two active motors, achieve the cooperative optimization of input-side torque balance and output-side power consistency, thereby improving the overall control quality and operational reliability of the system. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides an adaptive torque distribution synchronous control method and system for dual-input single-output motor bus systems.
[0006] In a first aspect, the present invention provides an adaptive torque distribution synchronous control method for a dual-input single-output motor bus system, the system comprising a first active motor, a second active motor, and a common output terminal, the method comprising: The operating status information of the first active motor and the second active motor, as well as the operating status information of the common output terminal, are obtained. The operating status information includes at least torque information. Based on the operating status information of the two active motors, the synchronization error characterizing the motion synchronization between the two active motors and the torque balance error characterizing the input-side torque balance are determined; and, based on the input torque of the two active motors, the output torque of the common output terminal and the dynamic parameters of the common output terminal, an input-output three-torque closed residual is constructed to characterize the consistency between the input-side driving torque and the output-side dynamic response. The disturbance compensation amount is generated based on the input-output three torque closed loop residuals; the adaptive torque distribution coefficient is generated based on the torque equalization error, the input-output three torque closed loop residuals and the load status of the two active motors; and the synchronization compensation amount is generated based on the synchronization error, the torque equalization error and the input-output three torque closed loop residuals. Based at least on the total driving force requirement of the system, the disturbance compensation amount, the adaptive torque distribution coefficient, and the synchronization compensation amount, the final torque command of the first active motor and the second active motor is generated and output.
[0007] As a preferred embodiment of the technical solution of the present invention, the torque information includes input torque and output torque; The input torque of the first active motor is obtained through a first torque sensor located in the first input branch, and the input torque of the second active motor is obtained through a second torque sensor located in the second input branch.
[0008] By independently setting the first torque sensor and the second torque sensor in the two input branches, the actual input torque of each active motor can be obtained in real time and accurately, avoiding the accuracy loss and parameter sensitivity caused by relying on motor model estimation, and providing a high-fidelity measured data basis for torque balance error calculation and three-torque closed residual construction.
[0009] As a preferred embodiment of the technical solution of the present invention, the operating status information further includes the angular position and angular velocity of the first active motor and the second active motor, as well as the angular velocity of the common output terminal; The synchronization error includes position synchronization error and speed synchronization error. The position synchronization error is determined based on the angular position of the two active motors, and the speed synchronization error is determined based on the angular velocity of the two active motors.
[0010] By acquiring the angular position and angular velocity of the two active motors and constructing position synchronization error and speed synchronization error respectively, a multi-dimensional characterization of the motion synchronization of the two motors is achieved. The position synchronization error reflects the steady-state coordination accuracy, while the speed synchronization error reflects the dynamic tracking consistency. The two complement each other, ensuring accurate synchronization of the system under steady-state conditions and improving transient synchronization performance during dynamic processes such as acceleration and deceleration, thus avoiding mechanical shocks and stress concentrations caused by position lag or speed mismatch.
[0011] As a preferred embodiment of the technical solution of the present invention, the torque balancing error is determined based on the ratio of the actual input torque of the first active motor and the maximum allowable torque of the second active motor.
[0012] Defining torque balancing error as the ratio of the actual input torque of two motors to their respective maximum allowable torque, rather than a simple torque difference, effectively takes into account the differences in motor capacity and rated parameters. This normalization method can accurately reflect the load balancing degree of each motor relative to its own limit capacity, providing a reasonable optimization guide for adaptive torque distribution and preventing small-capacity motors from being overloaded for a long time while large-capacity motors are underutilized.
[0013] As a preferred embodiment of the technical solution of the present invention, the dynamic parameters of the common output terminal include the equivalent moment of inertia and the equivalent damping coefficient of the common output terminal; the input-output three-torque closed residual is constructed based on the input torque of the two active motors and their corresponding transmission efficiency coefficients, the output torque of the common output terminal, the equivalent moment of inertia of the common output terminal, the angular acceleration of the common output terminal, the equivalent damping coefficient of the common output terminal, and the angular velocity of the common output terminal.
[0014] By taking the transmission efficiency coefficient into account, the power transfer loss from the motor to the output end of the bus system is fully reflected, enabling the residual signal to sensitively capture non-ideal factors such as changes in transmission chain efficiency, internal friction fluctuations, and external load disturbances, thus providing an accurate error driving source for disturbance compensation.
[0015] As a preferred embodiment of the technical solution of the present invention, the input-output three-torque closed residual is constructed according to the following formula:
[0016] in, At the current sampling time, The input-output three-torque closed-loop residual at the current sampling time. , These represent the input torques of the first and second active motors at the current sampling time. , These are the transmission efficiency coefficients of the first input branch and the second input branch, respectively. The output torque of the common output terminal at the current sampling time. The angular velocity of the common output terminal at the current sampling moment. The angular acceleration at the common output terminal at the current sampling moment. and These are the equivalent moment of inertia and equivalent damping coefficient of the common output terminal, respectively.
[0017] In this formula, the difference between the equivalent driving torque on the input side and the actual torque consumed at the output end directly reflects the combined effects of unmodeled dynamics, nonlinear friction, transmission backlash, and external disturbances within the system. This residual construction is simple and efficient, requires minimal computation, and is easy to implement online in real time.
[0018] As a preferred embodiment of the technical solution of the present invention, the angular acceleration at the common output terminal is obtained through the following filtering method:
[0019] The disturbance compensation amount is obtained by performing a first-order filter on the input-output three-torque closed-loop residual:
[0020] in, These are the angular accelerations at the current sampling time and the previous sampling time, respectively. These are the angular velocities at the current sampling time and the previous sampling time, respectively. These are the filter coefficients. The sampling period is These represent the disturbance compensation amounts at the current sampling time and the previous sampling time, respectively. The observer gain coefficient, The input-output three-torque closed residual is the current sampling time.
[0021] The use of first-order filtering to obtain angular acceleration effectively suppresses the high-frequency noise amplification problem caused by velocity signal differential. While ensuring the real-time performance of angular acceleration estimation, it improves the signal-to-noise ratio and avoids noise from being transmitted to the control system through the three-torque closed residual, thus preventing unnecessary control actions. (The first-order filtering of the input-output three-torque closed residual to generate disturbance compensation is equivalent to constructing a first-order disturbance observer, which can smoothly estimate the equivalent disturbance torque in the system. This ensures both the fast response capability of disturbance compensation and the effective suppression of measurement noise and abnormal fluctuations in residuals through filter coefficient adjustment, thus balancing compensation accuracy and noise immunity.)
[0022] As a preferred embodiment of the technical solution of the present invention, the update formula for the adaptive torque distribution coefficient is as follows:
[0023]
[0024] in, , These are the torque distribution coefficients of the first active motor at the current sampling time and the next sampling time, respectively. This represents the torque distribution coefficient of the second active motor at the next sampling time. The normalized torque equalization error, The normalized input-output three-torque closed-loop residuals, The difference in current load between the two active motors. , , These are the corresponding correction gain coefficients. For a saturating function, restrict the result to... Inside; The synchronization compensation amount is constructed as follows:
[0025] in, This is the synchronization compensation amount at the current sampling moment. For position synchronization error, For speed synchronization error, To compensate for torque balancing error, The normalized input-output three-torque closed-loop residuals, , , , These are the corresponding compensation gain coefficients.
[0026] Torque balancing error drives the distribution coefficient towards load balancing, the three-torque closed-loop residual guides the optimization of the distribution coefficient towards energy transfer consistency, and current load difference reflects the load status of the motor drive unit in real time from an electrical perspective. These three factors work together to ensure that the torque distribution strategy simultaneously considers mechanical load balancing, energy transfer efficiency, and electrical safety margin, achieving multi-objective optimization; the distribution coefficient is strictly limited to a certain value through a saturation function. Within the range, it ensures that both motors receive non-negative and reasonable torque commands under any operating condition, eliminating abnormal situations where a single motor command is zero or negative from the algorithm level, thus ensuring system safety. The construction of the synchronization compensation quantity organically integrates position synchronization error, speed synchronization error, torque balance error, and three torque closed residuals to form a multi-information fusion compensation strategy. Position and speed errors ensure the motion coordination of the two motors, torque balance error prevents the compensation process from disrupting torque balance, and the three torque closed residuals introduce input-output consistency constraints, realizing deep coupling and collaborative optimization of synchronous control and torque control.
[0027] As a preferred embodiment of the technical solution of the present invention, the step of generating and outputting the final torque command of the first active motor and the second active motor includes: Based on the total driving force requirement of the system and the adaptive torque distribution coefficient, the basic torque components of the first active motor and the second active motor are calculated; the synchronous compensation amount is superimposed on the basic torque components of the first active motor and the second active motor with opposite signs to obtain the reference torque commands of the first active motor and the second active motor respectively; the reference torque commands are subjected to safety limiting and torque change rate limiting processing to generate the final torque command.
[0028] The basic torque components of each motor are obtained by multiplying the adaptive torque distribution coefficient by the total driving force requirement, ensuring that the basic command meets the overall driving force requirements of the system, while also reflecting the optimization orientation of the distribution coefficient. The synchronous compensation is superimposed on the basic torque components of the two motors with opposite signs. When one motor lags behind, its torque command is increased while the command of the other motor is decreased synchronously, achieving synchronous correction without changing the total output torque. This ensures synchronization without affecting the total driving force output. The reference torque command is subjected to safety limiting and torque change rate limiting processing, forming the last safety barrier. This effectively prevents the command from exceeding the limit, which could lead to motor overload or driver saturation. At the same time, it limits the torque mutation rate to avoid impact loads on the transmission system, improving the system's operational safety and mechanical life.
[0029] Secondly, the present invention also provides an adaptive torque distribution synchronous control system for a dual-input single-output motor bus system, comprising a first active motor, a second active motor, a common output terminal, and a control unit, wherein the control unit includes: The information acquisition module is used to acquire the operating status information of the first active motor and the second active motor, as well as the operating status information of the common output terminal. The operating status information includes at least torque information. The error and residual construction module is used to determine the synchronization error, which characterizes the motion synchronization between the two active motors, and the torque balance error, which characterizes the torque balance on the input side, based on the operating status information of the two active motors. Furthermore, based on the input torque of the two active motors, the output torque of the common output terminal, and the dynamic parameters of the common output terminal, it constructs an input-output three-torque closed residual, which characterizes the consistency between the input driving torque and the output dynamic response. The compensation and allocation calculation module is used to generate disturbance compensation amount based on the input-output three torque closed residual, generate adaptive torque allocation coefficient based on the torque balance error, the input-output three torque closed residual and the load status of the two active motors, and generate synchronization compensation amount based on the synchronization error, the torque balance error and the input-output three torque closed residual; The instruction generation and output module is used to generate and output the final torque instructions of the first active motor and the second active motor, based at least on the total driving force requirement of the system, the disturbance compensation amount, the adaptive torque distribution coefficient, and the synchronization compensation amount.
[0030] As can be seen from the above technical solutions, this application has the following advantages: By simultaneously introducing evaluation indicators of three dimensions—synchronization error, torque balance error, and input-output three-torque closed-loop residuals—it achieves integrated perception of system motion synchronization, torque balance, and input-output energy consistency. The disturbance compensation amount generated based on the input-output three-torque closed-loop residuals can effectively suppress the influence of uncertainties such as sudden changes in external load, internal parameter perturbations, and unmodeled dynamics on the system, improving the system's robustness and anti-interference capability. Through the online updating of the adaptive torque distribution coefficient driven by torque balance error, three-torque closed-loop residuals, and motor load status, the torque distribution strategy can be dynamically optimized according to the real-time load capacity and operating conditions of the two motors, avoiding overload of a single motor and extending equipment lifespan. The generation of the synchronization compensation amount integrates multiple feedback information from synchronization error, torque balance error, and three-torque closed-loop residuals, achieving coordinated unity between motion synchronization control and torque balance control, effectively reducing torsional vibration and power cycle losses in the dual-motor bus system, improving bus efficiency and output motion smoothness. Attached Figure Description
[0031] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is a schematic diagram of the structure of a dual-input single-output servo experimental platform according to the present invention.
[0033] Figure 2 This is a schematic diagram of the dual-input single-output mechanical structure and measurement points proposed in an embodiment of the present invention.
[0034] Figure 3 The flowchart illustrates the adaptive torque distribution synchronization control method proposed in this invention.
[0035] Figure 4 This is a schematic diagram of the input-output three-torque closed residual structure proposed in an embodiment of the present invention.
[0036] Figure 5 This is a schematic diagram of adaptive torque distribution and synchronous compensation generation proposed in an embodiment of the present invention.
[0037] Figure 6 This is a comparison diagram of the common output speed response under the three-torque closed residual compensation of the present invention.
[0038] Figure 7 This diagram shows the results of adaptive torque distribution and torque balancing under branch asymmetry conditions according to the present invention.
[0039] Figure 8 The figure shows the results of multi-synchronization compensation and equivalent disturbance estimation in this invention.
[0040] In the figure, 101-loading motor, 102-inertia disk, 103-first active motor, 104-first input torque sensor, 105-T-shaped commutation mechanism, 106-second input torque sensor, 107-second active motor, 108-output torque sensor. Detailed Implementation
[0041] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0043] like Figure 1 and Figure 2 As shown, the present invention provides an adaptive torque distribution synchronous control system for a dual-input single-output motor based on input-output three-torque closed residual, including a first active motor 103, a second active motor 107, a dual-input single-output merging mechanism, and a common output terminal.
[0044] The dual-input single-output merging mechanism is used to mechanically couple the power input from two active motors and then output it as a single output. In this embodiment, the merging mechanism is implemented using a T-shaped commutation mechanism 105. However, in other embodiments, other forms of dual-input single-output coupling mechanisms, such as gear-type merging mechanisms, synchronous belt-type merging mechanisms, or planetary merging mechanisms, can also be used. This invention does not specifically limit the specific type of merging mechanism.
[0045] The first active motor 103 is mechanically connected to the first input end of the T-shaped commutation mechanism 105 via a first input branch. The first input branch refers to the mechanical transmission path that starts from the power output shaft of the first active motor 103, passes sequentially through the output shaft of the first active motor 103, the coupling, the first input torque sensor 104, and finally connects to the first input port of the T-shaped commutation mechanism 105.
[0046] The second active motor 107 is mechanically connected to the second input end of the T-shaped commutation mechanism 105 via a second input branch. The second input branch refers to the mechanical transmission path that starts from the power output shaft of the second active motor 107, passes sequentially through the output shaft of the second active motor 107, the coupling, the second input torque sensor 106, and finally connects to the second input port of the T-shaped commutation mechanism 105.
[0047] In other words, the T-shaped commutation mechanism 105 is a specific implementation of a dual-input single-output merging mechanism, containing two input ends and one output end. The first input branch and the second input branch refer to the power transmission paths outside the T-shaped commutation mechanism 105, connecting their respective main shaft motors to the input end of the merging mechanism. The T1(k) measured by the first input torque sensor 104 on the first input branch is the torque value actually transmitted from the external branch to the first input end of the merging mechanism; the T2(k) measured by the second input torque sensor 106 on the second input branch is the torque value actually transmitted from the external branch to the second input end of the merging mechanism. The output end of the T-shaped commutation mechanism 105 is a common output end, where an output torque sensor 108 is installed. The common output end is connected in sequence to the inertia disk 102 and the loading motor 101, which is used to simulate an external load.
[0048] The system also includes a control unit, which is electrically connected to the driver of the first active motor 103, the driver of the second active motor 107, the first input torque sensor 104, the second input torque sensor 106, the output torque sensor 108, and speed / position sensors disposed at the output terminals of each motor, for receiving sensor signals and outputting torque commands to the motor drivers. The control unit includes: The information acquisition module is used to acquire the operating status information of the first active motor and the second active motor, as well as the operating status information of the common output terminal. The operating status information includes at least torque information. The error and residual construction module is used to determine the synchronization error, which characterizes the motion synchronization between the two active motors, and the torque balance error, which characterizes the torque balance on the input side, based on the operating status information of the two active motors. Furthermore, based on the input torque of the two active motors, the output torque of the common output terminal, and the dynamic parameters of the common output terminal, it constructs an input-output three-torque closed residual, which characterizes the consistency between the input driving torque and the output dynamic response. The compensation and allocation calculation module is used to generate disturbance compensation amount based on the input-output three torque closed residual, generate adaptive torque allocation coefficient based on the torque balance error, the input-output three torque closed residual and the load status of the two active motors, and generate synchronization compensation amount based on the synchronization error, the torque balance error and the input-output three torque closed residual; The instruction generation and output module is used to generate and output the final torque instructions of the first active motor and the second active motor, based at least on the total driving force requirement of the system, the disturbance compensation amount, the adaptive torque distribution coefficient, and the synchronization compensation amount.
[0049] This invention also provides an adaptive torque distribution synchronization control method for a dual-input single-output motor bus system, applied to the control system described in the above embodiments. The invention defines the following system variables: First active motor status variable: angular position angular velocity Current First input branch torque ; Second active motor status variable: angular position angular velocity Current Torque of the second input branch ; Common output state quantity: angular velocity Output torque .
[0050] In addition, the system also defines the following control parameters: target angular velocity at the common output terminal. and target angular acceleration Equivalent moment of inertia at common output terminal and equivalent damping coefficient The transmission efficiency coefficients of the first and second input branches , .like Figure 3 As shown, the method includes the following steps: S1. Collect the angular position, angular velocity, current and first input branch torque of the first active motor; collect the angular position, angular velocity, current and second input branch torque of the second active motor; and collect the angular velocity and common output terminal torque. The angular position is obtained by the encoder built into the first active motor 103. and angular velocity The actual input torque of the first active motor is obtained by the first input torque sensor 104 located in the first input branch. The current is obtained through the current sampling circuit of the first active motor driver. .
[0051] The angular position is obtained by the encoder built into the second active motor 107. and angular velocity The actual input torque of the second active motor is obtained by the second input torque sensor 106 located in the second input branch. The current is obtained through the current sampling circuit of the second active motor driver. .
[0052] The angular velocity of the common output terminal is obtained through a speed sensor installed at the common output terminal. The output torque at the common output terminal is obtained by the output torque sensor 108 located at the common output terminal. .
[0053] S2. Based on the installation directions of the first and second active motors, set direction coefficients to convert the positions and velocities of the two active motors to the same reference direction; since the installation directions of the two active motors may differ, such as Figure 2 As shown, the first and second active motors are symmetrically mounted relative to the T-shaped commutation mechanism. They must rotate in opposite directions to achieve co-directional drive output. Therefore, the motion directions of the two motors need to be converted to the same reference direction to correctly calculate the synchronization error. Define the direction coefficient. The equivalent angular position and equivalent angular velocity after being converted to the same reference direction are as follows: , , , .
[0054] S3. Calculate the position synchronization error based on the converted positions of the two active motors, and calculate the speed synchronization error based on the converted speeds of the two active motors; based on these, the position synchronization error is determined according to the converted positions of the two active motors:
[0055] Speed synchronization error is determined based on the converted speeds of the two active motors:
[0056] in The desired position deviation angle between the two motors (under normal circumstances) =0, meaning the two motors are expected to be completely synchronized.
[0057] S4. Calculate the input branch torque balance error based on the first input branch torque and the second input branch torque; The torque equalization error is determined based on the ratio of the actual input torque of the first and second active motors to their maximum permissible torque. Let the maximum permissible torque of the first active motor be... The maximum permissible torque of the second active motor is Then the torque equalization error is defined as:
[0058] This definition method effectively takes into account the differences in capacity and rated parameters between the two motors. When When the value is greater than 0, it indicates that the relative load on the first motor is too high, and its distribution coefficient needs to be reduced; when... When the value is less than 0, it indicates that the relative load of the second motor is too high, and its distribution coefficient needs to be reduced.
[0059] S5. Based on the torque of the first input branch, the torque of the second input branch, the torque of the common output terminal, and the dynamic parameters of the common output terminal, construct the input-output three-torque closed residual. The dynamic equation for the common output terminal is:
[0060] in For unmodeled disturbances in the system (including sudden changes in external load, transmission efficiency fluctuations, backlash impacts, etc.), the disturbance can be obtained by processing them. The expression:
[0061] Define the input-output three-torque closed residual. For disturbance Inverse estimate:
[0062] The physical meaning of this residual is: the first term on the right. Characterizing the equivalent driving torque on the input side after transmission conversion The last three items on the right Characterized by the sum of the load torque, acceleration torque, and damping torque actually consumed at the output terminal, i.e., the equivalent dynamic torque at the common output terminal. The difference between the two This directly reflects the inconsistency between the input-side driving energy and the output-side dynamic response.
[0063] Traditional methods only determine whether the torques of the two branches are balanced (i.e., examine the difference between T1 and T2), while this invention further determines whether the torques of the two input branches form a closed-loop balance with the dynamic response of the common output terminal. Therefore, even when the speeds of the two motors are synchronized and the input torques are similar, this invention can still identify abnormal operating conditions at the output terminal through the three torque closed-loop residuals, such as sudden friction, backlash impact, branch elastic deformation, and decreased transmission efficiency.
[0064] In practical digital control systems, angular acceleration needs to be obtained through discrete differential filtering. The angular acceleration at the common output terminal is obtained using the following first-order filtering method:
[0065] in, For filter coefficients (0 < <1), The sampling period is specified. A first-order filtering method is used to obtain angular acceleration, which effectively suppresses the high-frequency noise amplification problem caused by velocity signal differential, and avoids severe fluctuations in the three-torque closed residual due to noise.
[0066] After incorporating the direction coefficient, the discrete-form input-output three-torque closed-loop residual is:
[0067] Figure 4 This is a schematic diagram of the input-output three-torque closed-loop residual construction proposed in an embodiment of the present invention, illustrating the construction logic of the three-torque closed-loop residual: the first input branch torque Second input branch torque Transmission efficiency coefficient , After conversion, the dynamic response at the common output terminal (by...) (Forming) a closed loop, the difference between the two is the three-torque closed residual. .
[0068] S6. Construct a disturbance estimate based on the input-output three-torque closed residual, and compensate the disturbance estimate to the total torque command at the common output terminal; Based on input-output three torque closing residuals The perturbation estimator is constructed using a first-order filter. The equivalent perturbation estimate after the first-order filter is:
[0069] in, At the current sampling time, These represent the disturbance compensation amounts at the current sampling time and the previous sampling time, respectively. The observer gain coefficient (0 < <1), The input-output three-torque closed residual is the current sampling time.
[0070] This formula is essentially a discretized implementation of a first-order perturbation observer. This observer will... The slowly changing components were extracted as equivalent disturbance torque. This is used to compensate for the effects of uncertainties on the system, such as sudden changes in external load, perturbations in internal parameters, and unmodeled dynamics. This is achieved by adjusting the observer gain coefficient. It can balance the rapid response capability of disturbance compensation with noise immunity.
[0071] First, calculate the speed error at the common output terminal:
[0072] Speed closed-loop control is achieved using a PI controller:
[0073]
[0074] in, For integration, and These are the proportional gain and integral gain of the velocity loop, respectively.
[0075] The total torque command at the common output terminal consists of the speed closed-loop PI control quantity, the feedforward term, and the disturbance compensation term:
[0076] in, This is the total torque command at the common output terminal at the current sampling moment. The output torque of the speed loop PI controller at the current sampling moment. This represents the disturbance compensation amount based on the three-torque closed residual observation at the current sampling time.
[0077] As another implementation method, when the output torque sensor is measurable, a load torque feedforward compensation method can also be used:
[0078] This method will measure the actual output torque. Incorporating it directly into the total torque command as a feedforward term can further improve the response speed to load disturbances.
[0079] S7. Based on the input branch torque balance error, input-output three torque closing residual and the current load difference of the two active motors, correct the torque distribution coefficient of the first active motor and the second active motor online. Define torque distribution coefficient and ,satisfy:
[0080]
[0081] To prevent a single motor from being completely unloaded or overloaded, upper and lower limits for the distribution coefficient are set:
[0082] Usually taken =0.2, =0.8, ensuring that both motors receive a non-negative and reasonable torque distribution under any operating condition.
[0083] The update of the adaptive torque distribution coefficient comprehensively considers three factors: torque equalization error, three-torque closure residual, and current-heat load difference. First, three normalized error quantities are defined: Torque equalization error (normalized):
[0084] Normalized closed residuals:
[0085] in The reference torque can be the rated torque of the motor or the maximum torque of the system in this embodiment of the invention.
[0086] Difference in current heat load:
[0087] in and These are the rated currents of the two motors, and The difference in current heat load between the two motors reflects the heating status of the motor drive unit from an electrical perspective. When the square ratio of the current of a certain motor is too large, it indicates that the motor has a higher risk of temperature rise and its distribution coefficient should be appropriately reduced.
[0088] The update formula for the allocation coefficients is:
[0089]
[0090] in, , These are the torque distribution coefficients of the first active motor at the current sampling time and the next sampling time, respectively. This represents the torque distribution coefficient of the second active motor at the next sampling time. The normalized torque equalization error, The normalized input-output three-torque closed-loop residuals, The difference in current load between the two active motors. , , These are the corresponding correction gain coefficients. For a saturating function, restrict the result to... The saturation function is defined as follows:
[0091] When the relative load of the first motor is too high ( When >0), this item makes Reduce, that is, lower the distribution coefficient of the first motor, and push the system to adjust towards torque balance; when When the value is >0, it indicates that the equivalent driving torque on the input side is greater than the actual demand on the output side, indicating that there is excess energy or abnormal transmission efficiency. This item guides the allocation coefficient to be optimized in the direction of improving the consistency between input and output. When the square ratio of the first motor current is too high, reduce its distribution coefficient to avoid overheating of the power devices.
[0092] Figure 5 This is a schematic diagram of adaptive torque distribution and synchronous compensation generation proposed in an embodiment of the present invention, showing the signal flow from error input to torque command output.
[0093] S8. Construct synchronization compensation based on position synchronization error, speed synchronization error, input branch torque balance error, and input-output three-torque closure residual; The synchronization compensation amount is constructed as follows:
[0094] in, This is the synchronization compensation amount at the current sampling moment. For position synchronization error, For speed synchronization error, To compensate for torque balancing error, The normalized input-output three-torque closed-loop residuals, , , , These are the corresponding compensation gain coefficients.
[0095] The construction of this compensation amount organically integrates four types of error signals: This is a position synchronization compensation term to ensure the steady-state position coordination of the two motors; This is a speed synchronization compensation term to ensure consistent dynamic speed tracking between the two motors; This is a torque balance compensation term to prevent the synchronous compensation process from disrupting the torque balance state; For the three-torque closed residual compensation term, an input-output consistency constraint is introduced.
[0096] The principle for determining the value of the above compensation gain coefficient is as follows: and As the primary gain, priority should be given to ensuring the basic performance of motion synchronization; and As an auxiliary gain, its value is relatively small, serving to constrain and optimize.
[0097] S9. Generate torque commands for the first and second active motors based on the total torque command from the common output terminal, the torque distribution coefficient, and the synchronization compensation amount. First, calculate the basic torque components of the two motors based on the total torque command and torque distribution coefficient:
[0098]
[0099] Then, the synchronization compensation is added to the base torque components of the two motors with opposite signs:
[0100]
[0101] This superposition method achieves a synchronous coordination strategy for differential regulation. The synchronous compensation amounts act in opposite directions on the two motors, therefore the sum of the torque commands of the two motors is:
[0102] That is, the amount of synchronous compensation does not change the total torque demand of the system, and does not affect the total output of the system while ensuring synchronization.
[0103] Then, a safety limiting process is implemented:
[0104]
[0105] To prevent sudden torque command changes from causing impact loads on the transmission system, it is also necessary to limit the rate of torque change:
[0106] The final output of the active motor input torque command is:
[0107]
[0108] Final torque command and The outputs are respectively sent to the drivers of the first and second active motors, and the drivers perform corresponding torque closed-loop control.
[0109] S10. Repeat the above steps in each sampling period to achieve adaptive torque distribution and coordinated synchronous control of the dual-input single-output motor bus system.
[0110] To verify the effectiveness of the adaptive torque distribution synchronization control method proposed in this invention, this embodiment... Figure 1 Simulation verification was performed on the dual-input single-output servo experimental platform shown. The simulation results are as follows: Figures 6-8 As shown, Figure 6 The diagram shows a comparison of the speed response at the common output terminal before and after enabling the three-torque closed-loop residual disturbance compensation under a sudden load disturbance. The upper curve represents the speed response without compensation, while the lower curve represents the speed response after enabling the three-torque closed-loop residual disturbance compensation described in this invention. Figure 7 This diagram shows the results of adaptive torque distribution and torque balancing under branch asymmetry conditions according to the present invention. Figure 7 The paper presents the dynamic adjustment process of the adaptive torque distribution coefficient of the present invention and the balancing result of the actual output torque of the two motors when the transmission efficiencies of the two input branches are asymmetrical. Figure 7 In the diagram, the upper curve represents the online variation trajectory of the torque distribution coefficient, while the lower curve represents the response waveform of the actual input torque of the two motors. Figure 8 This is a diagram showing the estimation results of the synchronization compensation amount and equivalent disturbance in this invention. Figure 8 The real-time variation waveforms of the synchronization compensation amount and the equivalent disturbance estimate described in this invention are presented. Figure 8 In the diagram, the upper curve represents the time-domain waveform of the synchronization compensation, while the lower curve represents a comparison between the first-order filtered disturbance estimate based on the three-torque closed-loop residuals and its corresponding actual equivalent disturbance. Simulation results show that the adaptive torque distribution synchronization control method for dual-input single-output motor combiner systems proposed in this invention, by introducing input-output three-torque closed-loop residuals into the traditional dual-motor synchronization control framework and simultaneously using them for disturbance observation compensation, adaptive torque distribution coefficient correction, and synchronization compensation construction, can effectively achieve balanced torque output of the two active motors, smooth operation of the common output terminal, and rapid suppression of comprehensive system disturbances under complex operating conditions such as asymmetrical branch transmission efficiency and sudden changes in external load. This improves the control quality and operational reliability of the dual-motor combiner system.
[0111] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. An adaptive torque distribution synchronous control method for a dual-input single-output motor bus system, the system comprising a first active motor, a second active motor, and a common output terminal, characterized in that, The method includes: The operating status information of the first active motor and the second active motor, as well as the operating status information of the common output terminal, are obtained. The operating status information includes at least torque information. Based on the operating status information of the two active motors, the synchronization error characterizing the motion synchronization between the two active motors and the torque balance error characterizing the input-side torque balance are determined; and, based on the input torque of the two active motors, the output torque of the common output terminal and the dynamic parameters of the common output terminal, an input-output three-torque closed residual is constructed to characterize the consistency between the input-side driving torque and the output-side dynamic response. The disturbance compensation amount is generated based on the input-output three torque closed loop residuals; the adaptive torque distribution coefficient is generated based on the torque equalization error, the input-output three torque closed loop residuals and the load status of the two active motors; and the synchronization compensation amount is generated based on the synchronization error, the torque equalization error and the input-output three torque closed loop residuals. Based at least on the total driving force requirement of the system, the disturbance compensation amount, the adaptive torque distribution coefficient, and the synchronization compensation amount, the final torque command of the first active motor and the second active motor is generated and output.
2. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 1, characterized in that, Torque information includes input torque and output torque; The input torque of the first active motor is obtained through a first torque sensor located in the first input branch, and the input torque of the second active motor is obtained through a second torque sensor located in the second input branch.
3. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 2, characterized in that, The operating status information also includes the angular position and angular velocity of the first and second active motors, as well as the angular velocity of the common output terminal; The synchronization error includes position synchronization error and speed synchronization error. The position synchronization error is determined based on the angular position of the two active motors, and the speed synchronization error is determined based on the angular velocity of the two active motors.
4. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 3, characterized in that, The torque equalization error is determined based on the ratio of the actual input torque of the first active motor to the maximum allowable torque of the second active motor.
5. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 4, characterized in that, The dynamic parameters of the common output terminal include the equivalent moment of inertia and the equivalent damping coefficient of the common output terminal; the input-output three-torque closed residual is constructed based on the input torque of the two active motors and their corresponding transmission efficiency coefficients, the output torque of the common output terminal, the equivalent moment of inertia of the common output terminal, the angular acceleration of the common output terminal, the equivalent damping coefficient of the common output terminal, and the angular velocity of the common output terminal.
6. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 5, characterized in that, The input-output three-torque closed residual is constructed according to the following formula: in, At the current sampling time, The input-output three-torque closed-loop residual at the current sampling time. , These represent the input torques of the first and second active motors at the current sampling time. , These are the transmission efficiency coefficients of the first input branch and the second input branch, respectively. The output torque of the common output terminal at the current sampling time. The angular velocity of the common output terminal at the current sampling moment. The angular acceleration at the common output terminal at the current sampling moment. and These are the equivalent moment of inertia and equivalent damping coefficient of the common output terminal, respectively.
7. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 4, characterized in that, The angular acceleration at the common output terminal is obtained through the following filtering method: The disturbance compensation amount is obtained by performing a first-order filter on the input-output three-torque closed-loop residual: in, These are the angular accelerations at the current sampling time and the previous sampling time, respectively. These are the angular velocities at the current sampling time and the previous sampling time, respectively. These are the filter coefficients. The sampling period is These are the disturbance compensation amounts for the current sampling time and the previous sampling time, respectively. The observer gain coefficient, The input-output three-torque closed residual is the current sampling time.
8. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 4, characterized in that, The update formula for the adaptive torque distribution coefficient: in, , These are the torque distribution coefficients of the first active motor at the current sampling time and the next sampling time, respectively. This represents the torque distribution coefficient of the second active motor at the next sampling time. The normalized torque equalization error, The normalized input-output three-torque closed-loop residuals, The difference in current load between the two active motors. , , These are the corresponding correction gain coefficients. For a saturating function, restrict the result to... Inside; The synchronization compensation amount is constructed as follows: in, This is the synchronization compensation amount at the current sampling moment. For position synchronization error, For speed synchronization error, To compensate for torque balancing error, The normalized input-output three-torque closed-loop residuals, , , , These are the corresponding compensation gain coefficients.
9. The adaptive torque distribution synchronization control method for a dual-input single-output motor combiner system according to claim 8, characterized in that, The steps for generating and outputting the final torque command for the first and second active motors include: Based on the total driving force requirement of the system and the adaptive torque distribution coefficient, the basic torque components of the first active motor and the second active motor are calculated; the synchronous compensation amount is superimposed on the basic torque components of the first active motor and the second active motor with opposite signs to obtain the reference torque commands of the first active motor and the second active motor respectively; the reference torque commands are subjected to safety limiting and torque change rate limiting processing to generate the final torque command.
10. An adaptive torque distribution synchronous control system for a dual-input single-output motor bus system, characterized in that, It includes a first active motor, a second active motor, a common output terminal, and a control unit, wherein the control unit includes: The information acquisition module is used to acquire the operating status information of the first active motor and the second active motor, as well as the operating status information of the common output terminal. The operating status information includes at least torque information. The error and residual construction module is used to determine the synchronization error, which characterizes the motion synchronization between the two active motors, and the torque balance error, which characterizes the torque balance on the input side, based on the operating status information of the two active motors. Furthermore, based on the input torque of the two active motors, the output torque of the common output terminal, and the dynamic parameters of the common output terminal, it constructs an input-output three-torque closed residual, which characterizes the consistency between the input driving torque and the output dynamic response. The compensation and allocation calculation module is used to generate disturbance compensation amount based on the input-output three torque closed residual, generate adaptive torque allocation coefficient based on the torque balance error, the input-output three torque closed residual and the load status of the two active motors, and generate synchronization compensation amount based on the synchronization error, the torque balance error and the input-output three torque closed residual; The instruction generation and output module is used to generate and output the final torque instructions of the first active motor and the second active motor, based at least on the total driving force requirement of the system, the disturbance compensation amount, the adaptive torque distribution coefficient, and the synchronization compensation amount.