Vehicle steering gear muddy water spraying test control system and method

Abstract

The invention relates to a vehicle steering gear muddy water spraying test control system and method. The system comprises a controller which is used for generating a temperature control instruction and spraying control information according to vehicle driving information, steering control information, steering gear working information and muddy water environment information; the heater is used for heating the vehicle steering gear under the control of the temperature control instruction; the frequency converter is used for outputting an analog quantity control signal according to the spraying control information; the spraying pump is used for spraying muddy water to the vehicle steering gear according to the analog quantity control signal; according to the invention, the simulation requirement of the steering gear is accurately controlled and simulated, so that the simulation effect or the matching between the simulation effect and the steering gear is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, specifically to a control system and method for mud and water spraying tests on vehicle steering gears. Background Technology

[0002] The steering gear mud and water spray test bench is a testing device used to simulate the mud and water erosion environment that a vehicle's steering system experiences when driving in harsh weather conditions (such as rain). Its core purpose is to evaluate the durability and reliability of the steering gear.

[0003] When existing steering gear mud spray test benches simulate the test environment, it is difficult to accurately simulate the steering gear according to the simulation requirements, resulting in poor simulation results or simulation results that do not match the working state of the steering gear. Summary of the Invention

[0004] In order to solve the technical problems in the prior art, such as the difficulty in accurately simulating the steering gear according to the simulation requirements, resulting in poor simulation effect or the simulation effect not matching the working state of the steering gear, the present invention provides a vehicle steering gear mud and water spray test control system and method.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A vehicle steering gear mud spray test control system includes: The controller is used to generate temperature control commands and spray control information based on vehicle driving information, steering control information, steering gear working information, and mud and water environment information. A heater, connected to the controller, is used to heat the vehicle steering system under the control of the temperature control command; A frequency converter, connected to the controller, is used to output analog control signals according to the spray control information; A spray pump, connected to the frequency converter, is used to spray mud and water onto the vehicle steering gear according to the analog control signal.

[0006] The beneficial effects of this invention are: based on preset vehicle driving information, steering control information, steering gear working information, and mud and water environment information, temperature control commands and spray control information are generated. Then, based on the temperature control commands and spray control information, the flow rate of mud and water spray and the temperature of the steering gear of the vehicle to be tested are controlled respectively. This achieves precise control and simulation of the steering gear's simulation requirements, thereby improving the simulation effect or the matching between the simulation effect and the steering gear.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, it also includes a flow sensor, which is connected to the controller; The flow sensor is used to monitor the flow rate of mud sprayed onto the vehicle steering gear, and outputs the sampled flow rate; The controller is also used to perform feedback control on the frequency converter based on the sampled flow rate output by the flow sensor and the set flow rate to output feedback control commands; wherein, the mud and water environment information includes the original flow rate, the vehicle driving information includes the vehicle speed, the steering gear operating information includes the steering gear load, and the steering control information includes the steering wheel torque; the set flow rate is equal to the sum of the original flow rate and the flow compensation value, and the flow compensation value is determined by the vehicle speed, the steering gear load, and the steering wheel torque; the spray control information includes the feedback control commands; The frequency converter is specifically used to output the analog control signal according to the feedback control command.

[0009] Furthermore, the feedback control method for the frequency converter is specifically a proportional-integral-derivative control method.

[0010] Furthermore, the proportional-integral-derivative control method is as follows: Calculate the flow error based on the sampled flow rate and the set flow rate; Calculate the proportional error, integral error, and differential error based on the flow rate error; The final gain is calculated based on the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain; wherein the feedback control command includes the feedback control quantity; The frequency converter is specifically used to output the analog control signal according to the feedback control quantity.

[0011] Furthermore, the flow error is calculated based on the sampled flow rate and the set flow rate, using the following formula: ; in, The first value of the flow sensor is indicated. Each sampling time, Indicates the first Flow rate error at the sampling time Indicates the first The set flow rate at the sampling time. Indicates the first Sampling flow rate at the sampling time.

[0012] Furthermore, the formula for calculating the proportional error is as follows: ; The formula for calculating the integral error is as follows: ; The formula for calculating the differential error is as follows: ; in, This indicates the proportional error. This represents the integration error. This represents the differential error. Indicates proportional gain. Indicates integral gain. Represents differential gain. This indicates the sampling interval.

[0013] Furthermore, the final gain is calculated based on the proportional error, the integral error, and the differential error. Specifically, the final gain is obtained by summing the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain. Specifically, the sum of the set flow rate and the final gain is calculated to obtain the feedback control quantity.

[0014] Furthermore, it also includes a temperature sensor, and the controller is connected to the temperature sensor; The temperature sensor is used to collect the temperature of the vehicle steering gear and obtain the measured temperature. The controller is also used to perform fuzzy PI control on the heater based on the measured temperature and the set temperature and generate the temperature control command; wherein, the steering gear operating information also includes the original temperature of the steering gear, the set temperature is equal to the sum of the original temperature and the temperature compensation value, and the temperature compensation value is determined by the vehicle speed, the steering gear load and the steering wheel torque.

[0015] Furthermore, it also includes a return water relay, a return water pump, and a water level sensor. The controller is connected to the return water relay and the water level sensor respectively, and the return water relay is connected to the return water pump. The water level sensor is used to collect the water level in the mud and water storage tank and obtain the water level signal; The controller is also used to perform fuzzy PI control on the return water relay according to the water level signal and generate on / off commands and time commands; The return water relay is used to control the duration and time of the return water pump's opening and closing according to the on / off command and the time command.

[0016] To address the aforementioned technical problems, this invention also provides a method for controlling the mud and water spray test of a vehicle steering gear, the specific technical content of which is as follows: A method for controlling a mud and water spray test on a vehicle steering gear includes the following steps: Temperature control commands and spray control information are generated based on vehicle driving information, steering control information, steering gear working information, and mud and water environment information. The vehicle steering gear is heated under the control of the temperature control command. Output analog control signals based on the spray control information; The flow rate of mud sprayed onto the vehicle steering gear is controlled according to the analog control signal. Attached Figure Description

[0017] Figure 1 This is a schematic block diagram of a vehicle steering gear mud spray test control system according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating a method for controlling a mud and water spray test on a vehicle steering gear according to an embodiment of the present invention. Figure 3 This is a flowchart of the proportional-integral-derivative control method in an embodiment of the present invention; Figure 4 This is a flowchart of fuzzy PI control in an embodiment of the present invention.

[0018] The attached diagram lists the components represented by each number as follows: 1. Controller, 2. Temperature sensor, 3. Heater, 4. Frequency converter, 5. Spray pump, 6. Vehicle steering gear, 7. Flow sensor, 8. Return water relay, 9. Return water pump, 10. Water level sensor. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] like Figure 1 As shown, this embodiment provides a vehicle steering gear mud and water spray test control system, including: Controller 1 is used to generate temperature control commands and spray control information based on vehicle driving information, steering control information, steering gear working information and mud and water environment information; Heater 3, connected to controller 1, is used to heat vehicle steering gear 6 under the control of the temperature control command; Inverter 4 is connected to the controller 1 and is used to output analog control signals according to the spray control information; The spray pump 5 is connected to the frequency converter 4 and is used to spray mud and water onto the vehicle steering gear 6 according to the analog control signal.

[0021] According to the preset vehicle driving information, steering control information, steering gear working information and mud and water environment information, the present invention generates temperature control commands and spray control information. Then, according to the temperature control commands and spray control information, the flow rate of mud and water spray and the temperature of the steering gear 6 of the vehicle to be tested are controlled respectively. This realizes precise control and simulation of the steering gear simulation requirements, so as to improve the simulation effect or the matching between the simulation effect and the steering gear.

[0022] In some embodiments, the above-described vehicle steering gear mud spray test control system further includes a flow sensor 7, which is connected to the controller 1; The flow sensor 7 is used to monitor the flow rate of mud sprayed onto the vehicle steering gear 6, and output the sampled flow rate. The controller 1 is also used to perform feedback control on the frequency converter 4 based on the sampled flow rate output by the flow sensor 7 and the set flow rate to output feedback control commands; wherein, the mud and water environment information includes the original flow rate, the vehicle driving information includes the vehicle speed, the steering gear working information includes the steering gear load, and the steering control information includes the steering wheel torque; the set flow rate is equal to the sum of the original flow rate and the flow compensation value, and the flow compensation value is determined by the vehicle speed, the steering gear load, and the steering wheel torque; the spray control information includes the feedback control commands.

[0023] The flow compensation value is determined by the vehicle speed, the steering gear load, and the steering wheel torque. Specifically, a vehicle speed flow compensation value association lookup table, a load flow compensation value association lookup table, and a torque flow compensation value association lookup table are constructed. A first flow compensation value is retrieved from the vehicle speed flow compensation value association lookup table based on the vehicle speed; a second flow compensation value is retrieved from the load flow compensation value association lookup table based on the steering gear load; and a third flow compensation value is retrieved from the torque flow compensation value association lookup table based on the steering wheel torque. The sum of the first, second, and third flow compensation values ​​is then calculated to obtain the aforementioned flow compensation value.

[0024] In the speed-flow compensation value lookup table, the first flow compensation value is positive when the vehicle speed is below 80 km / h, and negative when the vehicle speed is above or equal to 80 km / h. In the load-flow compensation value lookup table, the steering gear load and the second flow compensation value have a linear proportional relationship. For example, in some cases, when the steering gear load range is 0-12 kN, the spray volume increases linearly, and the steering gear load and the second flow compensation value are directly proportional; or, in other cases, such as different vehicle models with steering gears in the 0-12 kN steering gear load range, the spray volume decreases linearly, and the steering gear load and the second flow compensation value are inversely proportional. In the torque-flow compensation value lookup table, the steering wheel torque and the third flow compensation value are linearly proportional. For example, in some cases, when the steering wheel torque is in the range of 0-8 Nm, the spray volume increases linearly, and the steering wheel torque and the third flow compensation value are directly proportional. Or, in other cases, such as when different models of vehicle steering systems are in the range of 0-8 Nm, the spray volume decreases linearly, and the steering wheel torque and the third flow compensation value are inversely proportional.

[0025] The frequency converter 4 is specifically used to output the analog control signal according to the feedback control command; wherein, the feedback control method for the frequency converter 4 is specifically a proportional-integral-derivative control method.

[0026] The proportional-integral-derivative (PI-DE) control method is as follows: Calculate the flow error based on the sampled flow rate and the set flow rate; The flow error is calculated based on the sampled flow rate and the set flow rate, using the following formula: ; in, The flow sensor 7 represents the first Each sampling time, Indicates the first Flow rate error at the sampling time Indicates the first The set flow rate at the sampling time. Indicates the first Sampling flow rate at the sampling time.

[0027] Calculate the proportional error, integral error, and differential error based on the flow rate error; The formula for calculating the proportional error is as follows: ; The formula for calculating the integral error is as follows: ; The formula for calculating the differential error is as follows: ; in, This indicates the proportional error. This represents the integration error. This represents the differential error. Indicates proportional gain. Indicates integral gain. Represents differential gain. This indicates the sampling interval.

[0028] The final gain is calculated based on the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain; wherein the feedback control command includes the feedback control quantity; The frequency converter 4 is specifically used to output the analog control signal according to the feedback control quantity.

[0029] The final gain is calculated based on the proportional error, the integral error, and the differential error. Specifically, the final gain is obtained by summing the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain. Specifically, the sum of the set flow rate and the final gain is calculated to obtain the feedback control quantity.

[0030] In some embodiments, the above-described vehicle steering gear mud and water spray test control system further includes a temperature sensor 2, and the controller 1 is connected to the temperature sensor 2; The temperature sensor 2 is used to collect the temperature of the vehicle steering gear 6 and obtain the measured temperature; The controller 1 is also used to perform fuzzy PI control on the heater 3 according to the measured temperature and the set temperature and generate the temperature control command; wherein, the steering gear operating information also includes the original temperature of the steering gear, the set temperature is equal to the sum of the original temperature and the temperature compensation value, and the temperature compensation value is determined by the vehicle speed, the steering gear load and the steering wheel torque.

[0031] The temperature compensation value is determined by the vehicle speed, the steering gear load, and the steering wheel torque. Specifically, a lookup table for vehicle speed temperature compensation value, a lookup table for load temperature compensation value, and a lookup table for torque temperature compensation value are constructed. A first temperature compensation value is retrieved from the vehicle speed temperature compensation value lookup table based on the vehicle speed; a second temperature compensation value is retrieved from the load temperature compensation value lookup table based on the steering gear load; and a third temperature compensation value is retrieved from the torque temperature compensation value lookup table based on the steering wheel torque. The sum of the first, second, and third temperature compensation values ​​is then calculated to obtain the aforementioned temperature compensation value.

[0032] In the vehicle speed-temperature compensation value lookup table, the first temperature compensation value is positive when the vehicle speed is below 80 km / h, and negative when the vehicle speed is above or equal to 80 km / h. In the load-temperature compensation value lookup table, the steering gear load and the second temperature compensation value are linearly proportional. For example, in some cases where the steering gear load ranges from 0-12 kN, the temperature decreases linearly, and the steering gear load is inversely proportional to the second temperature compensation value. In the torque-temperature compensation value lookup table, the steering wheel torque and the third temperature compensation value are linearly proportional; for example, in some cases where the steering wheel torque ranges from 0-8 Nm, the temperature decreases linearly, and the steering wheel torque is inversely proportional to the third temperature compensation value.

[0033] In some embodiments, the above-mentioned vehicle steering gear mud spray test control system further includes a return water relay 8, a return water pump 9, and a water level sensor 10. The controller 1 is connected to the return water relay 8 and the water level sensor 10 respectively, and the return water relay 8 is connected to the return water pump 9. The water level sensor 10 is used to collect the water level in the mud and water storage tank and obtain the water level signal; The controller 1 is also used to perform fuzzy PI control on the return water relay 8 according to the water level signal and generate on / off instructions and time instructions. The return water relay 8 is used to control the duration and timing of the opening and closing of the return water pump 9 according to the on / off command and the time command.

[0034] In some embodiments, the above-mentioned vehicle steering gear mud spray test control system further includes a mixing pump, which is connected to a controller 1, and the controller 1 controls the start and stop of the mixing pump and the mixing speed.

[0035] In some other embodiments, a method for controlling a mud and water spray test on a vehicle steering gear is also provided, which includes the following steps: S1. Generate temperature control commands and spray control information based on vehicle driving information, steering control information, steering gear working information and mud and water environment information. S2. Heating the vehicle steering gear under the control of the temperature control command; S3. Output analog control signals according to the spray control information; S4. Control the flow rate of mud sprayed onto the vehicle steering gear according to the analog control signal.

[0036] like Figure 2 As shown, in some other embodiments, a PID control method is used to control the flow rate of mud sprayed onto the vehicle steering gear 6, that is, a frequency converter is used to control the spray pump, and the PID control calculates the control frequency.

[0037] Error calculation: e(k) = SP(k) - PV(k), where k is the index of the sampled signal at time k*t, and e(k) represents the current error. SP represents the set flow rate value, and PV represents the collected flow rate value.

[0038] Proportional operation, Up= *e(k), where, This indicates the controller gain.

[0039] Trapezoidal integration, and rectangular integration, At sampling interval Within, error value This method remains unchanged. It is simple, but its accuracy is low, especially when the error changes rapidly. To track changing signals more accurately, trapezoidal integrals are used to avoid drastic changes in the control quantity caused by parameter changes.

[0040] Local trapezoidal integral: The interval from k-1 to k is approximately a trapezoid. Therefore, all integrals are the sum of all trapezoids: Changes in integral between this output and the previous output: By averaging the two errors, a stable risk of integral saturation can be achieved.

[0041] Differential operation The purpose of differentiation is to respond quickly to changes, reduce overshoot, and improve stability. If the error is increasing, differentiation can suppress this increasing trend and achieve stability. On the other hand, when the error is decreasing, it reduces the output to prevent excessive subtraction.

[0042] Theoretical Differentiation: It is too sensitive to changes in error and needs to be improved as follows: When the differential time constant is very small, it is equivalent to the ideal differential; when it is very large, it weakens the differential effect.

[0043] Discretized backward difference: Difference between the current error and the previous error: Discretize Ds: When the setpoint SP changes, the error will change significantly. The differential will theoretically become infinite, which will manifest as a very high peak value, i.e., differential impact. The solution is to only differentiate the traffic feedback collected by PV to avoid differential impact.

[0044] Output = proportional operation + trapezoidal integral operation + derivative operation.

[0045] From the theoretical formula: After the above transformations, the final output becomes: The control output range of the frequency converter is min=0Hz, max=50Hz; If u ≥ 50, then let u = 50. If u≤0, then let u=0.

[0046] like Figure 3 As shown, in some other embodiments, the control method for heating the vehicle steering gear 6 under the control of the temperature control command is fuzzy PI control. Fuzzy PI control is applied to the return water relay 8 based on the water level signal to generate on / off commands and time commands.

[0047] The fuzzy PI control method is as follows: The fuzzy set is {negative large, negative medium, negative small, zero, positive small, positive medium, positive large}, denoted as {NB, NM, NS, ZO, PS, PM, PB}; When the absolute value of the error is large: Objective: To quickly eliminate errors and improve response speed.

[0048] Strategy: Take the larger one At the same time, to prevent integral saturation and overshoot, a smaller value is selected. (Even zero).

[0049] When the absolute value of the error is of moderate magnitude: Objective: To prevent system overshoot and make the response smoother.

[0050] Strategy: Appropriately reduce and take an appropriate amount .

[0051] When the absolute value of the error is very small: Objective: To eliminate steady-state error and improve stability accuracy.

[0052] Strategy: Continue to reduce To avoid oscillation, increase To enhance the integral effect and eliminate steady-state error.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vehicle deflector mud spray test control system, characterized by, include: The controller (1) is used to generate temperature control commands and spray control information based on vehicle driving information, steering control information, steering gear working information and mud and water environment information; Heater (3), connected to the controller (1), is used to heat the vehicle steering gear (6) under the control of the temperature control command; The frequency converter (4) is connected to the controller (1) and is used to output analog control signals according to the spray control information; A spray pump (5) is connected to the frequency converter (4) and is used to spray mud and water onto the vehicle steering gear (6) according to the analog control signal.

2. The vehicle deflector mud blast test control system of claim 1, wherein, It also includes a flow sensor (7), which is connected to the controller (1); The flow sensor (7) is used to monitor the flow rate of mud sprayed onto the vehicle steering gear (6) to output the sampled flow rate; The controller (1) is also used to perform feedback control on the frequency converter (4) based on the sampled flow rate output by the flow sensor (7) and the set flow rate to output feedback control commands; wherein, the mud and water environment information includes the original flow rate, the vehicle driving information includes the vehicle speed, the steering gear working information includes the steering gear load, and the steering control information includes the steering wheel torque; the set flow rate is equal to the sum of the original flow rate and the flow compensation value, and the flow compensation value is determined by the vehicle speed, the steering gear load, and the steering wheel torque; the spray control information includes the feedback control commands; The frequency converter (4) is specifically used to output the analog control signal according to the feedback control command.

3. The vehicle deflector mud blast test control system of claim 2, wherein, The feedback control method for the inverter (4) is specifically proportional-integral-derivative control.

4. The vehicle deflector mud blast test control system of claim 3, wherein, The proportional-integral-derivative (PI-DE) control method is as follows: Calculate the flow error based on the sampled flow rate and the set flow rate; Calculate the proportional error, integral error, and differential error based on the flow rate error; The final gain is calculated based on the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain; wherein the feedback control command includes the feedback control quantity; The frequency converter (4) is specifically used to output the analog control signal according to the feedback control quantity.

5. The vehicle deflector mud blast test control system of claim 4, wherein, The flow error is calculated based on the sampled flow rate and the set flow rate, using the following formula: ； wherein denotes a first sampling time of the flow sensor (7), denotes a second sampling time of the flow sensor (7), denotes a flow error at the first sampling time, denotes a flow error at the second sampling time, denotes a set flow at the first sampling time, denotes a set flow at the second sampling time, denotes a sampled flow at the first sampling time, and denotes a sampled flow at the second sampling time.

6. The vehicle steering gear mud and water spray test control system according to claim 5, characterized in that, The formula for calculating the proportional error is as follows: ； The formula for calculating the integral error is as follows: ； The formula for calculating the differential error is as follows: ； in, This indicates the proportional error. This represents the integration error. This represents the differential error. Indicates proportional gain. Indicates integral gain. Represents differential gain. This indicates the sampling interval.

7. The vehicle steering gear mud and water spray test control system according to claim 4, characterized in that, The final gain is calculated based on the proportional error, the integral error, and the differential error. Specifically, the final gain is obtained by summing the proportional error, the integral error, and the differential error. The feedback control quantity is calculated based on the set flow rate and the final gain. Specifically, the sum of the set flow rate and the final gain is calculated to obtain the feedback control quantity.

8. The vehicle steering gear mud and water spray test control system according to claim 2, characterized in that, It also includes a temperature sensor (2), and the controller (1) is connected to the temperature sensor (2); The temperature sensor (2) is used to collect the temperature of the vehicle steering gear (6) to obtain the measured temperature; The controller (1) is also used to perform fuzzy PI control on the heater (3) according to the measured temperature and the set temperature and generate the temperature control command; wherein, the steering gear working information also includes the original temperature of the steering gear, the set temperature is equal to the sum of the original temperature and the temperature compensation value, and the temperature compensation value is determined by the vehicle speed, the steering gear load and the steering wheel torque.

9. The vehicle steering gear mud and water spray test control system according to claim 1, characterized in that, It also includes a return water relay (8), a return water pump (9) and a water level sensor (10). The controller (1) is connected to the return water relay (8) and the water level sensor (10) respectively. The return water relay (8) is connected to the return water pump (9). The water level sensor (10) is used to collect the water level in the mud and water storage tank and obtain the water level signal; The controller (1) is also used to perform fuzzy PI control on the return water relay (8) according to the water level signal and generate on / off instructions and time instructions; The return water relay (8) is used to control the duration and time of opening and closing the return water pump (9) according to the on / off command and the time command.

10. A control method applied to the vehicle steering gear mud spray test control system as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Temperature control commands and spray control information are generated based on vehicle driving information, steering control information, steering gear working information, and mud and water environment information. The vehicle steering gear (6) is heated under the control of the temperature control command; Output analog control signals based on the spray control information; The flow rate of mud sprayed onto the vehicle steering gear (6) is controlled according to the analog control signal.

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