Brake particulate matter emission testing system

Abstract

The invention provides a braking particulate matter emission testing system. The braking particulate matter emission testing system is characterized in that an upper computer sends a target braking torque and a target rotating speed to a real-time controller; the real-time controller determines a target braking position according to the target braking torque and a torque closed-loop control algorithm, and determines a target loading torque according to a target rotating speed and a rotating speed closed-loop control algorithm; the torquemeter is used for collecting actual braking torque and feeding back the actual braking torque to the real-time controller; the real-time controller is further used for conducting feedforward compensation on the rotating speed according to the actual braking torque. Thus, the rotating speed and the torque are independently adjusted in a closed-loop mode through a double-closed-loop control strategy of a rotating speed closed-loop control algorithm and a torque closed-loop control algorithm, when the braking torque is adjusted, feedforward compensation is conducted on the rotating speed according to the actual braking torque, and equivalently, the rotating speed and the torque are decoupled; the feed-forward compensation can synchronously offset the interference to the rotating speed when the torque changes, and the simulation precision of the dynamic braking working condition is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, and in particular to a brake particulate matter emission testing system. Background Technology

[0002] As the automotive industry tightens its control over non-exhaust emissions, the accuracy requirements for brake particulate matter emission testing have been upgraded from qualitative screening to quantitative traceability. Brake particulate matter emission testing needs to be conducted based on the simulation of real braking conditions by the testing system, which places stringent requirements on the accuracy of the braking particulate matter emission testing system's simulation of operating conditions.

[0003] In related technologies, braking particulate matter testing systems typically employ simple open-loop or single closed-loop control structures when simulating braking conditions. These structures suffer from poor repeatability and slow dynamic response, leading to unstable control under dynamic braking conditions. Consequently, they affect the accuracy of the braking particulate matter system's simulation and fail to meet the high-precision requirements for braking particulate matter detection.

[0004] Therefore, there is a need for a braking particulate matter emission testing system to solve the technical problem that existing testing systems have low accuracy in simulating braking conditions, thus failing to meet the high-precision requirements for braking particulate matter detection. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a braking particulate matter emission testing system to solve or partially solve the technical problem that the existing testing systems cannot accurately simulate dynamic braking conditions, thereby affecting the accuracy of braking particulate matter emission detection.

[0006] This invention provides a braking particulate matter emission testing system, which is used to provide simulated braking conditions during particulate matter emission testing; the system includes: a host computer, a dynamometer, a torque meter, a brake actuator, and a real-time controller;

[0007] The host computer is used to send the target braking torque and target speed to the real-time controller; The real-time controller is used to determine the target braking position based on the target braking torque and the torque closed-loop control algorithm, and to determine the target loading torque based on the target speed and the speed closed-loop control algorithm. The brake actuator is used to adjust its own braking position to the target braking position according to the first control command sent by the real-time controller. The dynamometer is used to adjust the actual loading torque to the target loading torque according to the second control command sent by the real-time controller. A torque meter is used to collect the actual braking torque and feed the actual braking torque back to the real-time controller; The real-time controller is also used to perform feedforward compensation of the rotational speed based on the actual braking torque.

[0008] In the above scheme, the real-time controller is specifically used for: The feedforward compensation loading torque is determined using a speed closed-loop control algorithm and the actual braking torque, and the speed is compensated based on the feedforward compensation loading torque.

[0009] In the above scheme, the real-time controller is specifically used for: The change in braking torque is determined based on the target braking torque and the initial braking torque; The feedforward compensation loading torque is determined based on the change in braking torque and the feedforward compensation coefficient in the speed closed-loop control algorithm; the feedforward compensation loading torque is the product of the change in braking torque and the feedforward compensation coefficient.

[0010] In the above scheme, the real-time controller is specifically used for: Obtain the current loading torque of the dynamometer, and determine the torque and value based on the current loading torque and the feedforward compensation loading torque; The torque and value are sent to the frequency converter, which then drives the dynamometer to achieve the torque and value.

[0011] In the above scheme, the priority of the torque closed-loop control algorithm is higher than that of the torque closed-loop control algorithm.

[0012] In the above scheme, the real-time controller is further used for: After feedforward compensation of the rotational speed based on the actual braking torque, the actual rotational speed is obtained; Determine the speed deviation between the actual speed and the target speed; Adjust the actual loading torque according to the speed deviation so that the actual speed is consistent with the target speed.

[0013] In the above scheme, the system further includes: Environmental auxiliary equipment is used to provide the required ambient temperature, wind speed, and humidity during testing; Temperature control equipment is used to regulate the temperature of the target component during testing.

[0014] In the above scheme, the system further includes: A data acquisition device is used to collect operating data of each device during the test and send the operating data to a programmable logic controller. The operating data includes test data and status data. The test data includes torque, speed, and particulate matter flow rate. The status data includes brake actuator stroke, cooling flow rate, ambient temperature, ambient humidity, brake disc temperature, brake disc vibration data, and vibration data of the vibrating actuator. The programmable logic controller is used to perform a safety interlock trigger operation based on the status data.

[0015] In the above scheme, the programmable logic controller is specifically used for: If the status data is determined to exceed the corresponding limit, the power supply to the device corresponding to the status data is cut off, and an audible and visual alarm is triggered.

[0016] In the above scheme, the programmable logic controller is also electrically connected to the real-time controller through a communication network, and the programmable logic controller is also used to feed back the safety interlock status and the operating status of each device to the real-time controller.

[0017] This invention provides a braking particulate matter emission testing system, which provides simulated braking conditions during particulate matter emission testing. The system includes: a host computer, a dynamometer, a torque meter, a brake actuator, and a real-time controller. The host computer sends a target braking torque and a target rotational speed to the real-time controller. The real-time controller determines a target braking position based on the target braking torque and a torque closed-loop control algorithm, and determines a target loading torque based on the target rotational speed and a rotational speed closed-loop control algorithm. The brake actuator adjusts its braking position to the target braking position according to a first control command sent by the real-time controller. The dynamometer adjusts the actual loading torque to the target loading torque according to a second control command sent by the real-time controller. The torque meter... The system is used to collect the actual braking torque and feed it back to the real-time controller. The real-time controller is also used to perform feedforward compensation on the rotational speed based on the actual braking torque. In this way, by using a dual-loop control strategy of rotational speed closed-loop control algorithm and torque closed-loop control algorithm to independently adjust the rotational speed and torque, the control accuracy of rotational speed and torque can be ensured. Furthermore, when adjusting the braking torque, feedforward compensation on the rotational speed based on the actual braking torque is equivalent to decoupling the rotational speed and torque. Feedforward compensation can simultaneously cancel the interference on the rotational speed when the torque changes, avoiding the vicious cycle of torque changes affecting the rotational speed and then affecting the torque, thereby improving the simulation accuracy of dynamic braking conditions. Therefore, when detecting braking particulate matter under this braking condition, the detection accuracy of particulate matter can also be improved simultaneously. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the overall structure of a brake particulate matter emission testing system according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of a speed control loop and a torque control loop in a brake particulate emission testing system according to an embodiment of the present invention is shown. Figure 3 A schematic diagram of the pedal curve according to an embodiment of the present invention is shown; Figure 4 A schematic diagram comparing vehicle speed curves according to an embodiment of the present invention is shown; Figure 5 A schematic diagram comparing braking torque curves according to an embodiment of the present invention is shown. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0020] To better understand the technical solution of this invention, the relationship between the brake particulate matter emission testing system and brake particulate matter detection is first introduced. Brake particulate matter is particulate matter generated during braking, specifically solid particles generated by the high-temperature decomposition and wear of materials during the friction between the brake disc and brake pads. Therefore, to accurately detect the concentration of brake particulate matter, it is necessary to accurately simulate the braking condition using a particulate matter emission testing system before detecting brake particulate matter. Then, particulate matter can be collected using a particulate matter collection device under braking conditions, and the particulate matter concentration can be detected using a particulate matter detection device. The particulate matter collection device is generally installed near the brake disc.

[0021] To accurately detect brake particulate matter concentration, it is necessary to ensure that the brake particulate matter emission testing system can accurately simulate braking conditions. Therefore, this invention provides a brake particulate matter emission testing system that provides simulated braking conditions during particulate matter emission testing; such as Figure 1 As shown, the system includes: host computer 1, dynamometer 2, torque meter 3, brake actuator 4, and real-time controller 5; The host computer 1 is used to send the target braking torque and target speed to the real-time controller 5; Real-time controller 5 is used to determine the target braking position based on the target braking torque and torque closed-loop control algorithm, and to determine the target loading torque based on the target speed and speed closed-loop control algorithm; Brake actuator 4 is used to adjust its own braking position to the target braking position according to the first control command sent by real-time controller 5; Dynamometer 3 is used to adjust the actual loading torque to the target loading torque according to the second control command sent by real-time controller 5; Torque meter 3 is used to collect the actual braking torque and feed the actual braking torque back to the real-time controller 5; The real-time controller 5 is also used to feedforward compensation of the rotational speed based on the actual braking torque.

[0022] like Figure 1 As shown, the system also includes: load motor 6, frequency converter cabinet 7, environmental auxiliary equipment 8, data acquisition equipment 9, temperature control equipment (not shown in the figure), and programmable logic controller (PLC).

[0023] The load motor 6 is electrically connected to the frequency converter cabinet 7. The output shaft of the load motor 6 is connected to the input shaft of the dynamometer 2. The torque meter 3 is connected in series between the output shaft of the load motor 6 and the input shaft of the dynamometer 2. The output main shaft of the dynamometer 2 is connected to the brake disc.

[0024] The frequency converter cabinet 7 is connected to the real-time controller 5 through a high-speed IO interface, and the real-time controller 5 is connected to the host computer 1 through a LAN communication network.

[0025] Environmental auxiliary equipment 8 is used to provide the required ambient temperature, wind speed, and humidity during testing. Environmental auxiliary equipment 8 mainly includes: air conditioner, humidifier, dehumidifier, blower, air filter, and exhaust valve. Environmental auxiliary equipment 8 is primarily used to stabilize the temperature inside the test chamber at 23℃±1℃ and the humidity at 50%±5%, preventing temperature and humidity fluctuations from altering the friction coefficient of the brake pads and ensuring the stability of the braking torque. It also prevents particulate matter from condensing in high humidity environments and from electrostatic adsorption in low humidity environments, ensuring the accuracy of particulate matter sampling.

[0026] The system also features an air filter to purify the intake air, preventing external particulate matter from contaminating the particulate matter detection results. Furthermore, a blower can be used to regulate the airflow speed in the ductwork, maintaining a constant flow rate (e.g., 2L / min) within the particulate matter sampling pipeline to ensure consistent particulate matter collection efficiency. In the event of abnormalities such as excessive particulate matter concentration or equipment overheating within the testing chamber, the exhaust valve automatically activates to ventilate, ensuring the safety of testing personnel and equipment.

[0027] Temperature control equipment is primarily used to regulate the temperature of target components during testing. These components can include brake discs, brake pads, dynamometers, and more. Temperature control equipment may include water-cooled jackets, infrared heating modules, contact temperature sensors, and temperature controllers. For example, during braking, the water-cooled jacket can quickly dissipate the frictional heat from the brake disc; when not braking, the infrared heating module maintains the brake disc at a set temperature (e.g., 100℃±2℃) to ensure a stable coefficient of friction, thereby guaranteeing the accuracy of the braking torque.

[0028] In addition, temperature control equipment can provide forced heat dissipation for equipment that continuously generates heat, such as dynamometers and frequency converters, to maintain the operating temperature of these devices within a safe range (e.g., dynamometer temperature ≤ 80℃, frequency converter temperature ≤ 60℃), thus preventing overheating and damage to the equipment.

[0029] Data acquisition device 9 is connected to the PLC controller via a LAN communication network. Data acquisition device 9 collects the operating data of each device through the IO interface. The operating data includes test data and status data. Test data includes torque, speed and particulate matter flow, etc.; status data includes: brake actuator stroke, cooling flow, ambient temperature, ambient humidity, brake disc temperature, brake disc vibration data, vibration data of vibrating actuator, etc.

[0030] After acquiring various operational data, data acquisition device 9 sends test data to real-time controller 5 and status data to PLC controller. PLC controller can then upload the status data to a host computer via a LAN communication network, allowing operators to monitor the equipment's operational status in real time.

[0031] The PLC controller is also connected to the environmental auxiliary equipment 8 via a CAN communication network or a 485 communication interface, and is electrically connected to the brake actuator via a LAN communication network or a CAN communication network. The brake actuator is also electrically connected to the real-time controller 5. The brake actuator can send its braking position and braking pressure to the real-time controller, and its hydraulic pressure to the PLC controller.

[0032] The PLC controller can execute corresponding control strategies and safety interlock trigger operations based on various status data, specifically: When the programmable logic controller determines that the status data exceeds the corresponding limit, it cuts off the power supply to the device corresponding to the status data and triggers an audible and visual alarm.

[0033] For example, if the ambient temperature is determined to be below the target, the PLC controller will send instructions to adjust the opening of the air conditioning damper or the fan speed to maintain the ambient temperature at the preset temperature.

[0034] If it is determined that the brake actuator stroke exceeds the upper limit, the power supply to the brake actuator can be directly cut off, and the fault information of the brake actuator can be synchronized to the host computer, as well as triggering an audible and visual alarm.

[0035] The PLC controller is also electrically connected to the real-time controller 5 via a LAN communication network to provide feedback on the safety interlock status and the operating status of each device.

[0036] For example, if the safety interlock status reported by the PLC controller to the real-time controller is normal, then the test can continue. If the safety interlock status reported by the PLC controller to the real-time controller is "the brake actuator power has been cut off", then the real-time controller will determine that there is a fault in the system and will suspend the issuance of test commands.

[0037] For example, when the PLC controller determines that the ambient temperature is within the standard and stable, it will send a message to the real-time controller that the intake air conditioning temperature is stable; when the PLC controller detects that the cooling flow of the dynamometer is abnormal, the PLC controller will first check whether the cooling flow is insufficient. If so, it will send a message to the real-time controller that the cooling flow of the dynamometer is insufficient, which causes the cooling flow of the dynamometer to be below standard. The real-time controller can then reduce the load on the dynamometer to prevent the dynamometer from overheating.

[0038] In addition, the PLC controller can also store critical data (such as safety event logs and equipment operating status) locally. If the real-time controller or host computer fails, the PLC controller can serve as a data backup source to ensure the integrity of the test data.

[0039] When using the above system to conduct simulated operating condition tests, the host computer 1 can provide a human-machine interface. Users can edit the test curve corresponding to the target operating condition (such as the WLTP-Brake Cycle test cycle curve) in the interface. The host computer can then receive the target operating condition set by the user and determine the target braking torque and target speed at each time point based on the target operating condition. The target speed and target braking torque are then sent to the real-time controller 5. For example, the WLTP-Brake Cycle test cycle curve can be decomposed into the target braking torque and target speed at each time point.

[0040] The real-time controller 2 integrates a dual closed-loop control algorithm: a torque closed-loop control algorithm and a speed closed-loop control algorithm. The real-time controller 2 can determine the target braking position based on the target braking torque and the torque closed-loop control algorithm, and determine the target loading torque based on the target speed and the speed closed-loop control algorithm. The torque closed-loop control algorithm has a higher priority than the torque closed-loop control algorithm.

[0041] Accordingly, the control loop also includes two loops, such as... Figure 2 As shown, these are the torque control circuit and the speed control circuit, respectively. The torque control circuit also contains an actuator controller, and the speed control circuit also contains a frequency converter controller.

[0042] The dual closed-loop control algorithms operate independently but can be coupled through a physical carrier. Specifically, while the torque control loop and speed control loop operate independently in terms of algorithms, the torque loop controls the brake actuator (generating braking torque), and the speed control loop controls the load motor (generating loading torque). However, both torques act on the same rigid coaxial spindle (brake disc → torque meter → dynamometer → load motor shaft). This causes the output torques of the two loops to influence each other through this physical carrier, jointly determining the overall operating state. Therefore, this invention requires the system to feed back the actual torque to the torque closed-loop control algorithm and the speed to the speed closed-loop control algorithm to counteract the mutual interference caused by coupling, ultimately ensuring high precision in both torque and speed.

[0043] Specifically, in the torque control loop, the torque closed-loop control algorithm calculates the target braking position of brake actuator 4 based on the target braking torque output. The actuator controller converts the target braking position into the corresponding drive current of the servo motor. Based on the drive current, the servo motor rotates, which in turn pushes the hydraulic push rod of the brake actuator forward. When the hydraulic push rod pushes forward, it compresses the hydraulic oil inside the brake actuator, causing the hydraulic brake assembly (brake caliper) to generate high pressure. This pressure then pushes the brake pads towards the brake disc until they make close contact and generate stable positive pressure. After the brake pads contact the brake disc, the friction between them generates braking torque. This braking torque hinders the rotation of the brake disc, simulating the braking effect of a real vehicle.

[0044] The torque meter 3 will collect the actual braking torque in real time at a preset first frequency (e.g., 30kHz) and feed the actual braking torque back to the real-time controller 5. The real-time controller 5 compares the torque deviation between the actual braking torque and the target braking torque and issues a new position command to the brake actuator controller. If the actual braking torque is less than the target braking torque: drive the servo motor to continue pushing the push rod to increase the positive pressure on the brake pads; if the actual braking torque is greater than the target braking torque: drive the servo motor to rotate in the opposite direction, causing the push rod to retract and reducing the positive pressure on the brake pads; finally, stabilize the actual braking torque within the accuracy range of ±1% of the target braking torque to complete the torque closed-loop control.

[0045] In the speed control loop, the speed closed-loop control algorithm calculates the target loading torque based on the target speed. The real-time controller 5 sends the target loading torque to the frequency converter controller. The frequency converter controller converts the target loading torque into a variable frequency and variable voltage drive current and outputs the drive current to the load motor. The load motor adjusts its output torque according to the drive current and then transmits the loading torque to the brake disc through the coaxial spindle of the dynamometer.

[0046] The encoder on the load motor shaft collects the actual speed at a preset second frequency (e.g., 1kHz) and sends the actual speed to the real-time controller 5. The real-time controller 5 compares the speed deviation between the actual speed and the target speed, sends a new loading torque to the frequency converter controller, and repeats the above execution steps until the actual speed stabilizes within ±1 rpm of the target speed (target speed -1, target speed +1).

[0047] During the test, the braking torque and speed are coupled and therefore interfere with each other. To reduce this interference, the present invention performs feedforward compensation on the braking torque through the speed closed-loop control algorithm, thereby decoupling the speed control and torque control.

[0048] That is, once the real-time controller 5 obtains the actual torque, it is specifically used for: The feedforward compensation loading torque is determined by using a speed closed-loop control algorithm and the actual braking torque, and the speed is compensated based on the feedforward compensation loading torque.

[0049] In one implementation, the real-time controller 5 is specifically used for: The amount of change in braking torque is determined based on the target braking torque and the initial braking torque. The feedforward compensation loading torque is determined based on the change in braking torque and the feedforward compensation coefficient in the speed closed-loop control algorithm; the feedforward compensation loading torque is the product of the change in braking torque and the feedforward compensation coefficient.

[0050] In one implementation, the real-time controller 5 is specifically used for: Obtain the current loading torque of the dynamometer, and determine the torque and value based on the current loading torque and the feedforward compensation loading torque; The torque and value are sent to the frequency converter, which then drives the dynamometer to achieve the torque and value.

[0051] For example, if during dynamic braking, the braking torque needs to jump from 1000 Nm to 1500 Nm, the initial braking torque is 1000 Nm, the actual braking torque is 1500 Nm, and the change in braking torque is 500 Nm, then if the feedforward compensation coefficient is 0.25, the feedforward compensation loading torque is 500 Nm. 0.25 = 125 Nm.

[0052] The real-time controller 5 can directly superimpose a feedforward compensation torque of 125 Nm into the speed control command. If the current loading torque in the speed control command is 800 Nm, then the summed torque will be 925 Nm. Simultaneously with the torque change, the inverter controller synchronously increases the loading torque to 925 Nm. This causes the dynamometer speed to decrease slightly from 2000 rpm to 1990 rpm (instead of the uncompensated 1950 rpm), thus significantly reducing the interference of torque changes on the speed.

[0053] In this invention, the torque closed-loop control algorithm has a higher priority than the torque control loop control algorithm. That is, the torque control loop is the main control loop, and will be allocated computing resources first, adjusting the braking torque first, and then adjusting the speed. For example, during the process of adjusting the braking torque from 1000Nm to 1500Nm, the speed control loop only maintains the above torque and value (preventive small-range adjustment) and will not actively make large adjustments, thereby reducing interference to the torque control loop.

[0054] When the torque control loop achieves the target (the deviation between the actual braking torque and the target braking torque is ≤1%), the real-time controller 5 is also used for: The actual speed is obtained by feedforward compensation of the speed based on the actual braking torque; Determine the speed deviation between the actual speed and the target speed; Adjust the actual loading torque according to the speed deviation to make the actual speed consistent with the target speed.

[0055] For example, if the actual rotational speed is detected to be 1995 rpm, and there is still a speed deviation between the actual speed and the target speed of 200 rpm, then the actual loading torque will be increased slightly to gradually increase the speed to 2000 rpm ± 1 rpm.

[0056] Furthermore, the braking torque is monitored in real time during the speed adjustment process. If the torque fluctuation exceeds the preset ratio threshold (e.g., 1%) during the process of slightly increasing the actual loading torque, the speed adjustment will be stopped to prioritize torque stability.

[0057] In practical applications, when testing based on the above system, the main equipment parameters are as follows: Dynamometer: Rated power 200kW, maximum speed 3000rpm, speed control accuracy ±1rpm.

[0058] Torque meter: measuring range 0~5000Nm, frequency output: 30kHz.

[0059] Real-time controller: Used for control cycles of 1ms, supporting common industrial and network communication protocols such as RS232, RS485, CAN, Ethercat, TCP / IP, etc.

[0060] Brake actuator: servo motor driven, effective stroke: 150mm, maximum speed: 125mm / s, continuous thrust: 9KN.

[0061] The testing process is as follows: Step 1: Start the system and set the test room temperature to 23°C and humidity to 50%. Load the WLTP-BrakeCycle test cycle curve onto the host computer. The time series of accelerator pedal and brake pedal actions corresponding to the test cycle curve are as follows: Figure 3 As shown.

[0062] Step 2: At the start of the braking test, the speed control circuit controls the dynamometer to reach and maintain the initial speed. When braking is triggered (braking torque increases from 0), the torque control circuit activates, and the actuator pushes the brake pads to contact and generate torque. The braking torque acts on the dynamometer, causing the speed to tend to decrease. At this time, the speed control circuit detects the speed deviation and immediately increases the loading torque to maintain the set target speed, thereby simulating the vehicle's inertia.

[0063] During the dynamic braking phase, when the braking torque jumps from A to B, the torque control circuit starts to operate. The actuator pushes the brake pads to contact and generate torque, increasing the braking torque from A to B. Similarly, at this time, the speed control circuit detects the speed deviation and immediately increases the loading torque to maintain the set target speed.

[0064] Throughout the test, actual torque and actual speed will be collected in order to calculate braking performance indicators.

[0065] Furthermore, the real-time controller employs hardware timing to ensure the real-time performance of the control cycle, enabling rapid and accurate control. The torque comparison curves measured across the entire operating range are shown in Figure 4, and the vehicle speed comparison curves are shown in Figure 5. Figure 5 As shown. Since the purpose of rotational speed is to control speed measurement, and the operating condition simulation of the test system is also to simulate the driving conditions of real roads, vehicle speed is a direct reflection of the operating conditions. Therefore, a schematic diagram of the vehicle speed comparison curve is directly given here.

[0066] refer to Figure 4 Compared with the actual braking torque, after eliminating individual outliers, the steady-state torque error (with constant vehicle speed) is ≤1%, and the dynamic torque error (with changes in vehicle speed) is ≤5%. This indicates that the accuracy of the test system of the present invention in simulating the working conditions can meet the requirements.

[0067] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages: This invention provides a braking particulate matter emission testing system, which provides simulated braking conditions during particulate matter emission testing. The system includes: a host computer, a dynamometer, a torque meter, a brake actuator, and a real-time controller. The host computer sends a target braking torque and a target rotational speed to the real-time controller. The real-time controller determines a target braking position based on the target braking torque and a torque closed-loop control algorithm, and determines a target loading torque based on the target rotational speed and a rotational speed closed-loop control algorithm. The brake actuator adjusts its braking position to the target braking position according to a first control command sent by the real-time controller. The dynamometer adjusts the actual loading torque to the target loading torque according to a second control command sent by the real-time controller. The torque meter... The system is used to collect the actual braking torque and feed it back to the real-time controller. The real-time controller is also used to perform feedforward compensation on the rotational speed based on the actual braking torque. In this way, by using a dual-loop control strategy of rotational speed closed-loop control algorithm and torque closed-loop control algorithm to independently adjust the rotational speed and torque, the control accuracy of rotational speed and torque can be ensured. Furthermore, when adjusting the braking torque, feedforward compensation on the rotational speed based on the actual braking torque is equivalent to decoupling the rotational speed and torque. Feedforward compensation can simultaneously cancel the interference on the rotational speed when the torque changes, avoiding the vicious cycle of torque changes affecting the rotational speed and then affecting the torque, thereby improving the simulation accuracy of dynamic braking conditions. Therefore, when detecting braking particulate matter under this braking condition, the detection accuracy of particulate matter can also be improved simultaneously.

[0068] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A brake particulate matter emission testing system, characterized in that, The system is used to provide simulated braking conditions during particulate matter emission testing; the system includes: a host computer, a dynamometer, a torque meter, a brake actuator, and a real-time controller; The host computer is used to send the target braking torque and target speed to the real-time controller; The real-time controller is used to determine the target braking position based on the target braking torque and the torque closed-loop control algorithm, and to determine the target loading torque based on the target speed and the speed closed-loop control algorithm. The brake actuator is used to adjust its own braking position to the target braking position according to the first control command sent by the real-time controller. The dynamometer is used to adjust the actual loading torque to the target loading torque according to the second control command sent by the real-time controller. A torque meter is used to collect the actual braking torque and feed the actual braking torque back to the real-time controller; The real-time controller is also used to perform feedforward compensation of the rotational speed based on the actual braking torque.

2. The system as described in claim 1, characterized in that, The real-time controller is specifically used for: The feedforward compensation loading torque is determined using a speed closed-loop control algorithm and the actual braking torque, and the speed is compensated based on the feedforward compensation loading torque.

3. The system as described in claim 2, characterized in that, The real-time controller is specifically used for: The change in braking torque is determined based on the target braking torque and the initial braking torque; The feedforward compensation loading torque is determined based on the change in braking torque and the feedforward compensation coefficient in the speed closed-loop control algorithm; the feedforward compensation loading torque is the product of the change in braking torque and the feedforward compensation coefficient.

4. The system as described in claim 2, characterized in that, The real-time controller is specifically used for: Obtain the current loading torque of the dynamometer, and determine the torque and value based on the current loading torque and the feedforward compensation loading torque; The torque and value are sent to the frequency converter, which then drives the dynamometer to achieve the torque and value.

5. The system as described in claim 1, characterized in that, The priority of the torque closed-loop control algorithm is higher than that of the torque closed-loop control algorithm.

6. The system as described in claim 1, characterized in that, The real-time controller is also used for: After feedforward compensation of the rotational speed based on the actual braking torque, the actual rotational speed is obtained; Determine the speed deviation between the actual speed and the target speed; Adjust the actual loading torque according to the speed deviation so that the actual speed is consistent with the target speed.

7. The system as described in claim 1, characterized in that, The system also includes: Environmental auxiliary equipment is used to provide the required ambient temperature, wind speed, and humidity during testing; Temperature control equipment is used to regulate the temperature of the target component during testing.

8. The system as described in claim 1, characterized in that, The system also includes: A data acquisition device is used to collect operating data of each device during the test and send the operating data to a programmable logic controller. The operating data includes test data and status data. The test data includes torque, speed, and particulate matter flow rate. The status data includes brake actuator stroke, cooling flow rate, ambient temperature, ambient humidity, brake disc temperature, brake disc vibration data, and vibration data of the vibrating actuator. The programmable logic controller is used to perform a safety interlock trigger operation based on the status data.

9. The system as described in claim 8, characterized in that, The programmable logic controller is specifically used for: If the status data is determined to exceed the corresponding limit, the power supply to the device corresponding to the status data is cut off, and an audible and visual alarm is triggered.

10. The system as described in claim 8, characterized in that, The programmable logic controller is also electrically connected to the real-time controller via a communication network. The programmable logic controller is also used to provide feedback to the real-time controller on the safety interlock status and the operating status of each device.

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