A test bench for steer-by-wire and a load control method

Abstract

This invention proposes a steer-by-wire test bench and a load control method. The bench includes a host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system. The host computer is communicatively connected to the real-time simulator, which is in turn communicatively connected to the data acquisition system. The data acquisition system is communicatively connected to both the steer-by-wire system and the load loading system. The load loading system includes a load sensing module, which comprises a loading device and tension / compression sensors. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system via tension / compression sensors. Using the test bench of this invention improves the response speed.

Description

Technical Field

[0001] This invention relates to the field of steer-by-wire system testing technology, and in particular to a steer-by-wire test bench and load control method. Background Technology

[0002] Steer-by-wire systems control vehicle steering through electronic signals, greatly enhancing the driving experience. However, because they eliminate the mechanical connection between the steering wheel and the tires and lack a mechanical backup system, the reliability and safety of steer-by-wire systems become particularly critical. Thorough and comprehensive bench testing is essential before they can be put into mass production.

[0003] On the one hand, to ensure the authenticity and reliability of test results, the steer-by-wire test bench needs to simulate the load resistance during actual driving as accurately as possible. Currently, most load simulation devices use servo electric cylinders. While servo electric cylinders can simulate loads under different operating conditions, in actual operation, friction and wear between the servo motor and the cylinder liner increase the system's rotational inertia, leading to a slower response time for load control and making it difficult to achieve high-precision control. On the other hand, the presence of a network communication module inevitably generates dynamic network latency during steering bench testing. This not only affects the performance of load simulation but can also cause system instability in severe cases, posing a greater challenge to the control of load simulation. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the first objective of this invention is to provide a steer-by-wire test bench to improve response speed.

[0006] The second objective of this invention is to propose a load control method for a steer-by-wire test bench.

[0007] To achieve the above objectives, the first aspect of the present invention provides a steer-by-wire test bench, comprising a host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system; the host computer is communicatively connected to the real-time simulator, the real-time simulator is communicatively connected to the data acquisition system, and the data acquisition system is communicatively connected to both the steer-by-wire system and the load loading system.

[0008] The load loading system includes a load sensing module, which includes a loading device and a tension / compression sensor. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end of the rocker arm is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system through the tension / compression sensor.

[0009] In the steer-by-wire test bench provided in the first aspect of the present invention, there are multiple loading sensing modules, and different loading sensing modules are connected to different ends of the steer-by-wire system.

[0010] To achieve the above objectives, a second aspect of the present invention provides a load control method based on the steer-by-wire test bench provided in the first aspect of the present invention, comprising:

[0011] The host computer sends driver operation commands to the real-time simulator;

[0012] The data acquisition system sends the actual load force collected by the tension and compression sensors to the real-time simulator;

[0013] The real-time simulator obtains the desired load force based on the driver's operation command, and obtains the desired torque based on the desired load force, the nominal load force and the actual load force, and then generates the first control command and the second control command.

[0014] The steer-by-wire system performs steering actions based on the first control command;

[0015] The loading device obtains the desired torque based on the second control command, and drives the load motor to run based on the desired torque in order to dynamically load the steering-by-wire system.

[0016] In the load control method for a steer-by-wire test bench provided in the second aspect of the present invention, obtaining the desired torque based on the desired load force, the nominal load force and the actual load force includes: obtaining a corrected load force based on the nominal load force and the actual load force; and obtaining the desired torque based on the corrected load force and the desired load force.

[0017] In the load control method for the steer-by-wire test bench provided in the second aspect of the present invention, a nominal load loading system transfer function model is established using the frequency domain to obtain the nominal load force.

[0018] In the load control method for a steer-by-wire test bench provided in the second aspect of the present invention, the nominal load force satisfies:

[0019]

[0020] In the formula, F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. G i1 Let be the transfer function from the torque of the load motor corresponding to the i-th loading device to the corresponding load force. T mi ( sLet be the torque of the load motor corresponding to the i-th loading device. G i2 Let be the transfer function from the system disturbance to the corresponding load force for the i-th loading device. D i ( s ) represents the system disturbance corresponding to the i-th loading device.

[0021] In the load control method for a steering-by-wire test bench provided in the second aspect of the present invention, the step of obtaining a corrected load force based on the nominal load force and the actual load force includes: establishing a delay reducer based on the actual load force and the nominal load force to obtain the corrected load force.

[0022] In the steer-by-wire test bench load control method provided in the second aspect of the present invention, the corrected load force satisfies:

[0023]

[0024] In the formula, F Reqi ( s ) represents the corrected load force corresponding to the i-th loading device. L mi Let be the delay reduction coefficient corresponding to the i-th loading device. F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. F Ri ( s ) represents the actual load force corresponding to the i-th loading device.

[0025] In the load control method for a steer-by-wire test bench provided in the second aspect of the present invention, obtaining the desired torque based on the corrected load force and the desired load force includes: obtaining the desired torque by employing an active disturbance rejection control method according to the desired load force and the corrected load force.

[0026] In the steer-by-wire test bench load control method provided in the second aspect of the present invention, the desired torque satisfies:

[0027]

[0028] In the formula, T mi Let be the desired torque corresponding to the i-th loading device. b i1 , b i2 , a i1 , a i2 , For the control law parameters corresponding to the i-th loading device, fal (·) represents the fastest control synthesis function. e i1 Let be the load force tracking error corresponding to the i-th loading device. e i2 Let be the first derivative of the load force tracking error corresponding to the i-th loading device. b i For the system parameters corresponding to the i-th loading device, z i1 This is the estimated value of the system disturbance corresponding to the i-th loading device.

[0029] In this invention, the steer-by-wire test bench includes an integrated host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system. The load loading system includes a load sensing module, which comprises a loading device and tension / compression sensors. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system via tension / compression sensors. This test bench connects the load motor and the connecting shaft via the rocker arm, avoiding the friction and wear caused by using a servo motor and cylinder liners, thereby improving response speed. Furthermore, the steer-by-wire test bench load control method in this invention can handle the dynamic network delay present in the steer-by-wire test bench, improving the accuracy of load simulation.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0032] Figure 1 A block diagram of a steer-by-wire test bench provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the steer-by-wire test bench provided in an embodiment of the present invention;

[0034] Figure 3 This is a flowchart of the load control method for the steer-by-wire test bench provided in an embodiment of the present invention. Detailed Implementation

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of the present invention as detailed in the appended claims.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. It should also be understood that the term "and / or" as used in this invention refers to and includes any or all possible combinations of one or more associated listed items.

[0038] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0039] This invention proposes a steer-by-wire test bench and a load control method to improve response speed.

[0040] In an embodiment of the present invention, Figure 1 This is a block diagram of a steer-by-wire test bench provided in an embodiment of the present invention. In this invention, the steer-by-wire test bench can be simply referred to as a test bench or bench. Figure 1 As shown, the steer-by-wire test bench includes a host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system.

[0041] In this embodiment, the host computer and the real-time simulator are connected via communication. The connection method can be Ethernet communication.

[0042] In this embodiment, the host computer is used to send driver operation commands to the real-time simulator, and the host computer is also used to display the test interface.

[0043] In this embodiment, the real-time simulator is communicatively connected to the data acquisition system. This communication connection can be CAN bus communication.

[0044] In this embodiment, the real-time simulator receives driver operation commands to obtain the desired load force and runs a system model in real time to obtain the desired torque using the desired load force, nominal load force, and actual load force, thereby generating a first control command and a second control command including the desired torque. The real-time simulator sends the first control command to the steer-by-wire system through a data acquisition system, and the real-time simulator sends the second control command to the load loading system through the data acquisition system.

[0045] In this embodiment, the data acquisition system is communicatively connected to both the steer-by-wire system and the load loading system. This communication connection can be CAN bus communication.

[0046] In this embodiment, the data acquisition system is used to collect sensor data in the load loading system and transmit it to the real-time simulator. It is also used to collect interface data (such as the first control command and the second control command) of the real-time simulator and transmit it to the steer-by-wire system and the load loading system.

[0047] In this embodiment, the steer-by-wire system and the load-loading system are mechanically connected.

[0048] In this embodiment, the steer-by-wire system is used to perform steering actions according to a first control command.

[0049] In this embodiment, the load loading system is used to dynamically load the steer-by-wire system according to the second control command.

[0050] In this embodiment, the load loading system includes a load sensing module. The load sensing module includes a loading device and a tension / compression sensor. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end of the rocker arm is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system via the tension / compression sensor.

[0051] In this embodiment, there are multiple load sensing modules, and different load sensing modules are connected to different ends of the steering-by-wire system. For example, the load loading system includes two load sensing modules, which are respectively connected to the two ends of the steering-by-wire system.

[0052] Specifically, taking a load loading system comprising two load sensing modules as an example, the load loading system includes a first load sensing module and a second load sensing module. The first load sensing module includes a first loading device and a first tension / compression sensor. The second load sensing module includes a second loading device and a second tension / compression sensor.

[0053] Figure 2 This is a schematic diagram of the steer-by-wire test bench provided in an embodiment of the present invention. Figure 2 As shown, the steer-by-wire test bench includes a host computer 1, a real-time simulator 2, a data acquisition system 3, a steer-by-wire system 4, and a load loading system. The load loading system includes a first load sensing module and a second load sensing module. The first load sensing module includes a first loading device 51 and a first tension / compression sensor 52. The second load sensing module includes a second loading device 53 and a second tension / compression sensor 54. The host computer 1 and the real-time simulator 2 communicate via Ethernet. The real-time simulator 2 communicates with the data acquisition system 3, the steer-by-wire system 4, and each load sensing module via a CAN bus. The steer-by-wire system 4 and each load sensing module are mechanically connected.

[0054] The first loading device 51 includes a first load motor 511, a first rocker arm 512, a first connecting shaft 513, and a first load motor controller 514. The first loading device 51 and the first tension / compression sensor 52 constitute a first loading sensing module. In the first loading device 51, one end of the first rocker arm 512 is fixed to the first load motor 511, and the other end of the first rocker arm 512 is mechanically connected to the first connecting shaft 513. The first connecting shaft 513 is mechanically connected to one end of the steer-by-wire system 4 through the first tension / compression sensor 52.

[0055] The second loading device 53 includes a second load motor 531, a second rocker arm 532, a second connecting shaft 533, and a second load motor controller 534. The second loading device 53 and the second tension / compression sensor 54 constitute a second loading sensing module. In the second loading device 53, one end of the second rocker arm 532 is fixed to the second load motor 531, and the other end of the second rocker arm 532 is mechanically connected to the second connecting shaft 533. The second connecting shaft 533 is mechanically connected to the other end of the steer-by-wire system 4 through the second tension / compression sensor 54.

[0056] The real-time simulator 2 obtains the desired load force based on the driver's operation command from the host computer 1, and obtains the desired torque based on the desired load force, the nominal load force, and the actual load force collected by the data acquisition system 3, thereby generating a first control command and a second control command including the desired torque; the real-time simulator 2 sends the first control command to the steer-by-wire system 4 through the data acquisition system 3 to control the steer-by-wire system 4 to perform steering actions, and the real-time simulator 2 sends the second control command to the first loading device 51 and the second loading device 53 through the data acquisition system 3.

[0057] The first load motor controller 514 obtains the corresponding desired torque according to the corresponding second control command, and calculates the switching signal of the first load motor 511 drive device based on the desired torque and the actual torque of the first load motor 511 to drive the first load motor 511 to run, so that the actual torque is the same as the desired torque, thereby realizing dynamic loading on one end of the steer-by-wire system 4; the second load motor controller 534 obtains the corresponding desired torque according to the corresponding second control command, and calculates the switching signal of the second load motor 531 drive device based on the desired torque and the actual torque of the second load motor 531 to drive the second load motor 531 to run, thereby making the actual torque the same as the desired torque, thereby realizing dynamic loading on the other end of the steer-by-wire system 4.

[0058] The following are embodiments of the method of the present invention. For details not disclosed in the embodiments of the method of the present invention, please refer to the system embodiments of the present invention. The embodiments of the method of the present invention propose a load control method for a steer-by-wire test bench. This load control method for a steer-by-wire test bench utilizes the steer-by-wire test bench described in the above system embodiments for load control. The load control method for a steer-by-wire test bench of the present invention can be simply referred to as a control method.

[0059] Figure 3 This is a flowchart of the load control method for the steer-by-wire test bench provided in an embodiment of the present invention.

[0060] like Figure 3 As shown, the load control method for the steer-by-wire test bench includes:

[0061] Step S101: The host computer sends the driver's operation command to the real-time simulator.

[0062] In step S101, the driver's operation command carries the desired load force. The number of desired load forces is equal to the number of loading sensor modules, that is, each loading sensor module corresponds to one desired load force. Taking a load loading system including two loading sensor modules as an example, the driver's operation command carries a first desired load force and a second desired load force.

[0063] In step S102, the data acquisition system sends the actual load force collected by the tension and compression sensors to the real-time simulator.

[0064] In step S102, the data acquisition system and each loading sensor module communicate via a CAN bus. The tension / compression sensors in each loading sensor module monitor the actual load force of the corresponding loading device. The data acquisition system collects the actual load force monitored by the tension / compression sensors in each loading sensor module and sends it to the real-time simulator. Taking a load loading system comprising two loading sensor modules as an example, the data acquisition system sends the first actual load force monitored by the first tension / compression sensor and the second actual load force monitored by the second tension / compression sensor to the real-time simulator.

[0065] In step S102, after the real-time simulator obtains the first actual load force and the second actual load force, it can first filter the two actual load forces and then participate in the subsequent calculations.

[0066] In step S103, the real-time simulator obtains the desired load force based on the driver's operation command, and obtains the desired torque based on the desired load force, nominal load force and actual load force, and then generates the first control command and the second control command.

[0067] In step S103, the real-time simulator parses the desired load force from the driver's operating instructions.

[0068] In step S103, the real-time simulator obtains the desired torque based on the desired load force, nominal load force, and actual load force, including: obtaining the corrected load force based on the nominal load force and actual load force; and obtaining the desired torque based on the corrected load force and desired load force.

[0069] Specifically, a transfer function model of the nominal load-loaded system is established using the frequency domain to obtain the nominal load force. The nominal load force satisfies:

[0070]

[0071] In the formula, F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. G i1 Let be the transfer function from the torque of the load motor corresponding to the i-th loading device to the corresponding load force. T mi ( s Let be the torque of the load motor corresponding to the i-th loading device. G i2 Let be the transfer function from the system disturbance to the corresponding load force for the i-th loading device. D i ( s) represents the system disturbance corresponding to the i-th loading device.

[0072] The corrected load force is obtained based on the nominal and actual load forces, including: establishing a delay reducer based on the actual and nominal load forces to obtain the corrected load force. The corrected load force satisfies:

[0073]

[0074] In the formula, F Reqi ( s ) represents the corrected load force corresponding to the i-th loading device. L mi Let be the delay reduction coefficient corresponding to the i-th loading device. F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. F Ri ( s ) represents the actual load force corresponding to the i-th loading device.

[0075] Obtaining the desired torque based on the modified load force and the desired load force includes: using an active disturbance rejection control method to obtain the desired torque based on the desired load force and the modified load force. The desired torque satisfies:

[0076]

[0077] In the formula, T mi Let be the desired torque corresponding to the i-th loading device. b i1 , b i2 , a i1 , a i2 , For the control law parameters corresponding to the i-th loading device, fal (·) represents the fastest control synthesis function. e i1 Let be the load force tracking error corresponding to the i-th loading device. e i2 Let be the first derivative of the load force tracking error corresponding to the i-th loading device. b i For the system parameters corresponding to the i-th loading device, z i1 This is the estimated value of the system disturbance corresponding to the i-th loading device.

[0078] Taking a load loading system including a first load sensing module and a second load sensing module as an example, combined with... Figure 2The process of obtaining the first desired torque corresponding to the first loading sensing module and the second desired torque corresponding to the second loading sensing module is as follows:

[0079] For the nominal load capacity: A transfer function model of the nominal load loading system is established in the frequency domain to obtain the nominal load capacity corresponding to the first loading device 51 and the nominal load capacity corresponding to the second loading device 53; wherein, the transfer function model of the nominal load loading system satisfies:

[0080]

[0081] In the formula, F Rp1 ( s ) is the nominal load force corresponding to the first loading device (i.e., the first nominal load force). G 11 This is the transfer function from the torque of the load motor corresponding to the first loading device to the corresponding load force (i.e., the transfer function from the torque of the first load motor to the first load force). T m1 ( s ) is the torque of the load motor corresponding to the first loading device (i.e., the torque of the first load motor). G 12 Let be the transfer function from the system disturbance corresponding to the first loading device to the corresponding load force. D 1( s ) represents the system disturbance corresponding to the first loading device. F Rp2 ( s ) is the nominal load force corresponding to the second loading device (i.e., the second nominal load force). G 21 This is the transfer function from the torque of the load motor corresponding to the second loading device to the corresponding load force (i.e., the transfer function from the torque of the second load motor to the second load force). T m2 ( s ) is the torque of the load motor corresponding to the second loading device (i.e., the torque of the second load motor). G 22 Let be the transfer function from the system disturbance corresponding to the second loading device to the corresponding load force. D 2( s ) represents the system disturbance corresponding to the second loading device.

[0082] Regarding the actual load capacity, it should be noted that the specific formula for the actual load capacity transfer function model of the load loading system is as follows:

[0083]

[0084] in, FR ( s () represents the actual load force. G 1 represents the transfer function from the load motor torque to the corresponding load force. G 2 represents the transfer function from system disturbance to the corresponding load force. T m ( s () represents the torque of the load motor. D ( s () represents system disturbance. The network latency is represented by the data monitored by the tension and compression sensors. Considering that the network latency value changes dynamically and cannot be measured during the test, the data is directly used as the actual load force. Subsequently, a latency reducer is introduced in combination with the nominal load force to reduce the error between the actual load force transfer function model and the data monitored by the tension and compression sensors.

[0085] Specifically, a first delay reducer is established based on the first actual load force and the first nominal load force to obtain a first corrected load force (i.e., the corrected load force corresponding to the first loading device 51); a second delay reducer is established based on the second actual load force and the second nominal load force to obtain a second corrected load force (i.e., the corrected load force corresponding to the second loading device 53); the first corrected load force satisfies:

[0086]

[0087] In the formula, F Req1 ( s ) is the first corrected load force; L m1 This is the time delay reduction coefficient corresponding to the first loading device (i.e., the first time delay reduction coefficient). F Rp1 ( s ) is the nominal load force corresponding to the first loading device (i.e., the first nominal load force). F R1 ( s ) is the actual load force corresponding to the first loading device (i.e., the first actual load force).

[0088] The second corrected load force satisfies:

[0089]

[0090] In the formula, F Req2 ( s () represents the second corrected load force; L m2 This is the time delay reduction coefficient corresponding to the second loading device (i.e., the second time delay reduction coefficient). F Rp2 ( s) is the nominal load force corresponding to the second loading device (i.e., the second nominal load force). F R2 ( s ) is the actual load force corresponding to the second loading device (i.e., the second actual load force).

[0091] The first desired torque (i.e., the desired torque corresponding to the first loading device) of the first load motor 511 is obtained by using an active disturbance rejection control method based on the first desired load force and the first corrected load force; the second desired torque (i.e., the desired torque corresponding to the second loading device) of the second load motor 531 is obtained by using an active disturbance rejection control method based on the second desired load force and the second corrected load force; the first desired torque satisfies:

[0092]

[0093] In the formula, T m1 For the first desired torque, b 11 , b 12 , a 11 , a 12 , These are the control law parameters corresponding to the first loading device. fal (·) represents the fastest control synthesis function. e 11 This represents the load force tracking error corresponding to the first loading device. e 11 =r1-z1, where r1 is the first expected load capacity after transition processing, and z1 is the estimated value of the first corrected load capacity. e 12 This is the first derivative of the load force tracking error corresponding to the first loading device. e 12 =r2-z2, where r2 is the first derivative of the first expected load force after transition processing, and z2 is the estimated value of the first derivative of the first corrected load force. b 1 represents the system parameter corresponding to the first loading device. z 11 This represents the estimated system disturbance corresponding to the first loading device. The estimated values ​​of the first desired load force after transition processing, the first corrected load force, the first derivative of the first desired load force after transition processing, and the first derivative of the first corrected load force can be obtained through active disturbance rejection control (ADCC).

[0094] The second desired torque satisfies:

[0095]

[0096] In the formula,T m2 For the second desired torque, b 21 , b 22 , a 21 , a 22 , These are the control law parameters corresponding to the second loading device. fal (·) represents the fastest control synthesis function. e 21 This refers to the load force tracking error corresponding to the second loading device. e 21 =r3-z3, where r3 is the second expected load capacity after transition processing, and z3 is the estimated value of the second corrected load capacity. e 22 This is the first derivative of the load force tracking error corresponding to the second loading device. e 22 =r4-z4, where r4 is the first derivative of the second expected load force after transition processing, and z4 is the estimated value of the first derivative of the second corrected load force. b 2 represents the system parameters corresponding to the second loading device. z 21 This represents the estimated system disturbance corresponding to the second loading device. The estimated values ​​of the second desired load force after transition processing, the second corrected load force, the first derivative of the second desired load force after transition processing, and the first derivative of the second corrected load force can be obtained through active disturbance rejection control (ADCC).

[0097] In step S104, the steer-by-wire system performs a steering action based on the first control command.

[0098] In step S105, the loading device obtains the desired torque based on the second control command, and drives the load motor to run based on the desired torque in order to dynamically load the steering-by-wire system.

[0099] In step S105, the first loading device drives the first load motor 511 to rotate according to the desired torque corresponding to the first load motor 511, and the second loading device drives the second load motor 531 to rotate according to the desired torque corresponding to the second load motor 531. Specifically, the first load motor controller 514 obtains the first desired torque according to the corresponding second control command, and calculates the switching signal of the first load motor 511 drive device to drive the first load motor 511 to run based on the first desired torque and the actual torque of the first load motor 511, thereby making the actual torque the same as the first desired torque, realizing dynamic loading on one end of the steer-by-wire system 4; the second load motor controller 534 obtains the second desired torque according to the corresponding second control command, and calculates the switching signal of the second load motor 531 drive device to drive the second load motor 531 to run based on the second desired torque and the actual torque of the second load motor 531, thereby making the actual torque the same as the second desired torque, realizing dynamic loading on the other end of the steer-by-wire system 4.

[0100] It should be noted that the foregoing explanation of the steer-by-wire test bench embodiment also applies to the steer-by-wire test bench load control method of this embodiment, and will not be repeated here.

[0101] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0102] The steer-by-wire test bench and load control method in this invention include a host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system. The load loading system includes a load sensing module, which comprises a loading device and a tension / compression sensor. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system via the tension / compression sensor. This test bench connects the load motor and the connecting shaft via the rocker arm, avoiding the friction and wear caused by using a servo motor and cylinder liners, thereby improving response speed. The steer-by-wire test bench proposed in this invention has a relatively small moment of inertia in the load loading system, which can reduce the response time during load control and improve load loading performance. Furthermore, the load control method of the present invention is a load control method for a steer-by-wire test bench with dynamic network delay reduction function. The delay reducer of this method can handle the dynamic network delay present in the steer-by-wire test bench and improve the load simulation accuracy of the dynamic load loading device of the test bench. Moreover, the present invention further develops a dynamic delay reduction algorithm based on the classic active disturbance rejection control method, which makes the control algorithm structure and design simple and suitable for engineering applications.

[0103] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0104] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this invention does not impose any limitations on this.

[0105] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A load control method for a steer-by-wire test bench, characterized in that, The steer-by-wire test bench includes a host computer, a real-time simulator, a data acquisition system, a steer-by-wire system, and a load loading system. The host computer is communicatively connected to the real-time simulator, the real-time simulator is communicatively connected to the data acquisition system, and the data acquisition system is communicatively connected to both the steer-by-wire system and the load loading system. The load loading system includes a load sensing module, which includes a loading device and a tension / compression sensor. The loading device includes a load motor, a rocker arm, a connecting shaft, and a load motor controller. One end of the rocker arm is fixed to the load motor, and the other end of the rocker arm is mechanically connected to the connecting shaft. The connecting shaft is also mechanically connected to one end of the steer-by-wire system via the tension / compression sensor. The method includes: The host computer sends driver operation commands to the real-time simulator; The data acquisition system sends the actual load force collected by the tension and compression sensors to the real-time simulator; The real-time simulator obtains the desired load force based on the driver's operation command, and obtains the desired torque based on the desired load force, the nominal load force and the actual load force, and then generates the first control command and the second control command. The steer-by-wire system performs steering actions based on the first control command; The loading device obtains the desired torque based on the second control command, and drives the load motor to run based on the desired torque in order to dynamically load the steering-by-wire system; Specifically, a transfer function model of the nominal load-loaded system is established using the frequency domain to obtain the nominal load force, which satisfies the following: In the formula, F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. G i1 Let be the transfer function from the torque of the load motor corresponding to the i-th loading device to the corresponding load force. T mi ( s Let be the torque of the load motor corresponding to the i-th loading device. G i2 Let be the transfer function from the system disturbance to the corresponding load force for the i-th loading device. D i ( s ) represents the system disturbance corresponding to the i-th loading device.

2. The load control method for the steer-by-wire test bench according to claim 1, characterized in that, The process of obtaining the desired torque based on the desired load force, the nominal load force, and the actual load force includes: The corrected load force is obtained based on the nominal load force and the actual load force; The desired torque is obtained based on the corrected load force and the desired load force.

3. The load control method for the steer-by-wire test bench according to claim 1, characterized in that, There are multiple load sensing modules, and different load sensing modules are connected to different ends of the steer-by-wire system.

4. The load control method for the steer-by-wire test bench according to claim 2, characterized in that, The process of obtaining the corrected load force based on the nominal load force and the actual load force includes: A delay reducer is established based on the actual load force and the nominal load force to obtain the corrected load force.

5. The load control method for the steer-by-wire test bench according to claim 4, characterized in that, The corrected load force satisfies: In the formula, F Reqi ( s ) represents the corrected load force corresponding to the i-th loading device. L mi Let be the delay reduction coefficient corresponding to the i-th loading device. F Rpi ( s ) represents the nominal load force corresponding to the i-th loading device. F Ri ( s ) represents the actual load force corresponding to the i-th loading device.

6. The load control method for the steer-by-wire test bench according to claim 2, characterized in that, The process of obtaining the desired torque based on the corrected load force and the desired load force includes: The desired torque is obtained by using an active disturbance rejection control method based on the desired load force and the corrected load force.

7. The load control method for the steer-by-wire test bench according to claim 6, characterized in that, The desired torque satisfies: In the formula, T mi Let be the desired torque corresponding to the i-th loading device. b i1 , b i2 , a i1 , a i2 , For the control law parameters corresponding to the i-th loading device, fal (·) represents the fastest control synthesis function. e i1 Let be the load force tracking error corresponding to the i-th loading device. e i2 Let be the first derivative of the load force tracking error corresponding to the i-th loading device. b i For the system parameters corresponding to the i-th loading device, z i1 This is the estimated value of the system disturbance corresponding to the i-th loading device.

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