An integrated control system for a steering system and an active suspension

Abstract

The application discloses an integrated control system of a steering system and an active suspension, which comprises a sensor information acquisition unit, an information processing and central control unit, a steering performance calculation unit, a turning radius adjusting unit and an active suspension mode selection unit. The sensor information acquisition unit is used for collecting basic data of a vehicle during driving; the information processing and central control unit is used for receiving the data collected by the sensor information acquisition unit, processing the collected data and inputting the processed data into the steering performance calculation unit and the active suspension mode selection unit, and simultaneously sending corresponding control instructions; the steering performance calculation unit is used for calculating the steering performance of the vehicle; the turning radius adjusting unit is used for adjusting the turning radius according to the steering performance evaluation index Q of the vehicle; and the active suspension mode selection unit is used for selecting a corresponding active suspension adjustment mode according to the steering mode of the vehicle.

Description

Technical Field

[0001] This invention relates to an integrated control system for a steering system and an active suspension. Background Technology

[0002] During vehicle steering, improper driver operation or other factors can lead to unsatisfactory steering effects, easily resulting in rollovers or fishtailing. This not only affects passenger comfort but can even threaten the safety of occupants. An integrated control system for the steering system and active suspension reduces the likelihood of these situations. It assesses the vehicle's steering performance and adjusts the active suspension mode accordingly. However, current research primarily focuses on the individual control of the steering system and active suspension, failing to provide timely compensation for unsatisfactory steering performance. Therefore, to address these issues, this invention proposes an integrated control system for the steering system and active suspension. Summary of the Invention

[0003] The purpose of this invention is to provide an integrated control system for a steering system and an active suspension to solve the problems encountered in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an integrated control system for a steering system and an active suspension, comprising: a sensor information acquisition unit, an information processing and central control unit, a steering performance calculation unit, a turning radius adjustment unit, and an active suspension mode selection unit;

[0005] The sensor information acquisition unit is used to collect basic data of the vehicle during driving, including vehicle speed sensor, body acceleration sensor, wheel acceleration sensor, yaw rate sensor, vehicle load sensor, turning radius sensor, and steering wheel angle sensor.

[0006] The information processing and central control unit is used to receive data collected from the sensor information acquisition unit, process the collected data and input it into the steering performance calculation unit and the active suspension mode selection unit, and send corresponding control commands to them.

[0007] The steering performance calculation unit is used to calculate the vehicle's steering performance, including:

[0008] S1. Establish a turning radius model for the vehicle when it turns. The turning radius R of the vehicle satisfies the following formula:

[0009]

[0010] Where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius in the direction of the vehicle.

[0011] S2. Calculate the various indicators of the steering system according to the following formulas, including:

[0012] S2.1 Calculate the tire condition index Q1 according to the following formula:

[0013]

[0014] Where α1, α2, and α3 are weighting coefficients, μ represents the tire's road adhesion coefficient (μ = 0.4 for wet roads, μ = 0.6 for wet cement roads, and μ = 0.8 for dry cement roads), q 11 This represents the vehicle load factor, the value of which depends on the vehicle's loading condition. When the vehicle is fully loaded, q... 11 =1.2, when the vehicle is half-loaded, q 11 =1.0, when the vehicle is unloaded, q 11 =0.8, q 12 q represents the tire pressure state coefficient. When the tire is a high-pressure tire, q 12 =1.5, when the tire is a low-pressure tire, q 12 =1.1, when the tire is an ultra-low pressure tire, q 12 =0.7, q 13 q represents the tire wear coefficient. When the tire is in a slightly worn state, q 13 =0.9, when the tire is in a state of moderate wear, q 13 =1.3, when the tire is in a severely worn state, q 13 =1.8, when the tires are not worn, q 13 =1.0, q 14 q represents the tire tread depth coefficient. When the tire tread depth is less than 3mm, q 14 =0.5, when the tire tread depth is 3-8mm, q 14 =0.7, when the tire tread depth is 8-10mm, q 14 =1.0, q 15 q represents the tire mass variation coefficient. When high-quality tires are used, q 15 =2.0, q in other cases 15 =1.0;

[0015] S2.2 Calculate the tire process performance index Q2 according to the following formula:

[0016]

[0017] Where α4, α5, and α6 are weighting coefficients, τ represents the tire pass rate, which is equal to the ratio of the number of tires that meet the standards in the same batch of tires to the total number of tires inspected, and q 21q represents the tire construction coefficient. When the tire used is a radial tire, q 21 =1.2, when the tires used are bias-ply tires, q 21 =0.9, q 22 q represents the tire tread pattern variation coefficient. When the tire tread pattern is a stripe pattern, q 22 =0.5, when the tire tread pattern is transverse, q 22 =0.6, when the tire tread pattern is a mixed pattern, q 22 =0.7, when the tire tread pattern is an off-road tread pattern, q 22 =0.8, q 23 q represents the tire performance factor, which indicates the tire's performance on muddy roads. 23 =0.7, when the tire is used on icy and snowy roads, q 23 =1.1, when the tire is used as a spare tire, q 23 =1.4, q in other cases 23 =1.0, q 24 q represents the tire wear performance coefficient. When a tire has good wear resistance, q is... 24 =2.0, when the tire does not have good wear resistance, q 24 =0.2, q 25 q represents the coefficient of variation in tire vulcanization processes. When a variable temperature vulcanization process is used for tires, q represents the coefficient of variation. 25 =1.3, when the tire uses injection molding, q 25 =1.4, when the tire uses nitrogen vulcanization process, q 25 =1.5, q 26 q represents the tire's dynamic performance coefficient, which depends on the tire's stability and grip during vehicle cornering. When the tire has good grip on a wet surface, q... 26 =0.9, when the tire has good grip on dry roads, q 26 =1.0, when the tire has good grip on icy and snowy roads, q 26 =1.6;

[0018] S2.3 Calculate the driver state sub-index Q3 during the steering process according to the following formula:

[0019]

[0020] Where α7, α8, and α9 are weighting coefficients, and q 31 q represents the driver's visual impact coefficient during turning, when there is a pedestrian in front of the vehicle. 31 =0.7, when there are other vehicles in front of the vehicle, q 31 =0.8, when there are other obstacles in front of the vehicle, q 31 =1.1, q32 q represents the driver's physical condition coefficient; when the driver is steering while fatigued, q 32 =1.0, when the driver is turning while ill, q 32 =0.9, when the driver makes a turn while intoxicated, q 32 =0.5, q 33 This represents the driver's driving skill coefficient. When the driver's driving experience is less than or equal to 1 year, q 33 =0.2, when the driver's driving experience is greater than 1 year and less than 5 years, q 33 =0.6, when the driver's driving experience is greater than or equal to 5 years, q 33 =1.0, q 34 q represents the driver's age coefficient, which is set when the driver's age is greater than or equal to 18 years old and less than 35 years old. 34 =1.5, when the driver's age is greater than or equal to 35 years old and less than 55 years old, q 34 =1.4, when the driver's age is greater than or equal to 55 years old and less than 75 years old, q 34 =0.7, when the driver's age is greater than or equal to 75, q 34 =0.4, q 35 This represents the driver's reaction speed coefficient, the value of which depends on the driver's reaction time during a turn in case of an emergency, such as a sudden braking of the vehicle in front or a sudden change in traffic lights. When the driver's reaction time is less than or equal to 2 seconds, q... 35 =2.0, when the driver's reaction time is greater than 2 seconds and less than 5 seconds, q 35 =1.5, when the driver's reaction time is greater than or equal to 5 seconds, q 35 =1.0, q 36 This represents the driver's attention coefficient, q, when the driver makes or receives a phone call while turning. 36 =0.5, when the driver is fully focused on steering, q 36 =1.3, q in other cases 36 =0.8;

[0021] S2.4 Calculate the power steering fluid state index Q4 during the steering process using the following formula:

[0022]

[0023] Where, α 10 α 11 q is the weighting coefficient. 41 q represents the viscosity coefficient of the power steering fluid. 41 =0.5σ, where σ is the viscosity of the power steering fluid, σ = KωR 4K represents the instrument constant of the rotational viscometer, ω is the rotational speed, R is the radius of the rotating cylinder, and q 42 q represents the power steering fluid moisture content coefficient. When the moisture content is less than or equal to 0.5%, q 42 =1.2, when the moisture content is greater than 0.5% and less than 1.0%, q 42 =0.9, when the moisture content is greater than or equal to 1.0%, q 42 =0.6, q 43 q represents the acid value coefficient of the power steering fluid. When the acid value of the power steering fluid is less than or equal to 0.1, q 43 =1.1, when the acid value of the power steering fluid is greater than 0.1 and less than 0.3, q 43 =0.8, when the acid value of the power steering fluid is greater than or equal to 0.3, q 43 =0.5, q 44 q represents the mechanical impurity coefficient of the power steering fluid. When impurities are present in the power steering fluid, q 44 =1.5, when there are no impurities in the power steering fluid, q 44 =0.2, q 45 q represents the pour point coefficient of the power steering fluid. When the pour point of the power steering fluid is less than or equal to -40℃, q 45 =1.4, when the pour point of the power steering fluid is greater than -40℃, q 45 =0.7, q 46 q represents the anti-foaming coefficient of power steering fluid. Its value depends on the height of the foam generated after stirring the power steering fluid and the foam dissipation time. When the foam height is less than or equal to 10 mm and the foam dissipation time is less than or equal to 15 seconds, q 46 =1.8, when the foam height is greater than 10mm and the foam dissipation time is greater than 15 seconds, q 46 =0.6;

[0024] S2.5 Calculate the steering column state sub-index Q5 during the steering process according to the following formula:

[0025]

[0026] Where, α 12 α 13 q is the weighting coefficient. 51 q represents the material coefficient of the steering column. When the steering column is made of steel, q 51 =0.7, when the steering column is made of aluminum alloy, q 51 =0.9, when the steering column is made of composite material, q 51 =1.1, q 52 This represents the adjustment method coefficient of the steering column. When the steering column is mechanically adjustable, q 52= 0.8. When the steering column is electrically adjustable, q 52 = 1.2, q 53 represents the wear degree coefficient of the steering column. When the steering column is slightly worn and does not affect vehicle steering, q 53 = 0.5. When the steering column is severely worn and causes insensitive steering, q 53 = 1.5, q 54 represents the lubricating oil coefficient of the steering column. When the lubricating oil used for the steering column is gear oil, q 54 = 0.3. When the lubricating oil used for the steering column is engine oil, q 54 = 0.6. When the lubricating oil used for the steering column is special steering oil, q 54 = 1.0;

[0027] [[ID=1,9]]S3. Calculate the steering performance evaluation index Q according to the following formula:

[0028]

[0029] where, γ1, γ2, γ3, γ4, γ5 are the weighted values for calculating single - item indexes;

[0030] According to the size of the steering performance evaluation index Q, the vehicle steering can be divided into the first - level steering mode, the second - level steering mode, and the third - level steering mode. Among them, both the first - level steering mode and the third - level steering mode are non - ideal steering modes, and the second - level steering mode is an ideal steering mode. By introducing the first - level steering mode decision threshold δ1, the second - level steering mode decision threshold δ2, and the third - level steering mode decision threshold δ3, it is determined which steering mode the vehicle belongs to when steering. Among them, 0 < δ1 < δ2 < δ3 < 1; when the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the vehicle does not steer. When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the vehicle steering mode is the first - level steering mode. When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the vehicle steering mode is the second - level steering mode. When the steering performance evaluation index Q satisfies δ3 < Q < 1, the vehicle steering mode is the third - level steering mode;

[0031] The turning radius adjustment unit is used to adjust the turning radius according to the steering performance evaluation index Q of the vehicle. The turning radius adjustment unit is divided into the first - level turning radius adjustment unit, the second - level turning radius maintaining unit, and the third - level turning radius adjustment unit. When the vehicle is in the first - level steering mode, the turning radius adjustment unit executes the first - level turning radius adjustment unit. When the vehicle is in the second - level steering mode, the turning radius adjustment unit executes the second - level turning radius maintaining unit. When the vehicle is in the third - level steering mode, the turning radius adjustment unit executes the third - level turning radius adjustment unit;

[0032] When the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the turning radius adjustment unit does not work;

[0033] When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the turning radius adjustment unit executes the first-level turning radius adjustment unit, and the turning radius R1 of the vehicle satisfies the following formula:

[0034]

[0035] where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction;

[0036] When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the turning radius adjustment unit executes the second-level turning radius holding unit, and the turning radius is not adjusted;

[0037] When the steering performance evaluation index Q satisfies δ3 < Q < 1, the turning radius adjustment unit executes the third-level turning radius adjustment unit, and the turning radius R3 of the vehicle satisfies the following formula:

[0038]

[0039] where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction;

[0040] The active suspension mode selection unit is used to select the corresponding active suspension adjustment mode according to the steering mode of the vehicle. When the vehicle is in the first-level steering mode, the mode of the active suspension is the first-level adjustment mode, that is, to increase the roll stiffness of the suspension and increase the lateral adhesion of the tire. When the vehicle is in the second-level steering mode, the mode of the active suspension is the second-level holding mode, and the suspension is not adjusted. When the vehicle is in the third-level steering mode, the mode of the active suspension is the third-level adjustment mode, that is, to reduce the roll stiffness of the suspension and reduce the lateral adhesion of the tire;

[0041] The roll stiffness C of the suspension satisfies the following formula:

[0042]

[0043] where C is the roll stiffness of the suspension, C s is the spring stiffness, C<​​​​​​​​​​​​

[0044] The lateral adhesion force F of the tire y Satisfies the following formula:

[0045] F y = μF z q 13

[0046] Where, F y is the lateral adhesion force of the tire, μ is the road adhesion coefficient of the tire, F z is the normal load of the tire, q 13 is the tire wear degree coefficient;

[0047] When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the active suspension mode selection unit executes the first-level adjustment mode, and the roll stiffness C1 of the suspension satisfies the following formula:

[0048]

[0049] The lateral adhesion force F of the tire y1 Satisfies the following formula:

[0050]

[0051] When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the active suspension mode selection unit executes the second-level holding mode, and the suspension is not adjusted;

[0052] When the steering performance evaluation index Q satisfies δ3 < Q < 1, the active suspension mode selection unit executes the third-level adjustment mode, and the roll stiffness C2 of the suspension satisfies the following formula:

[0053]

[0054] The lateral adhesion force F of the tire y2 Satisfies the following formula:

[0055]

[0056] When the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the active suspension mode selection unit does not work.

[0057] Compared with the prior art, the beneficial effects of the present invention:

[0058] 1. An integrated control system for a steering system and an active suspension, comprising: a sensor information acquisition unit, an information processing and central control unit, a steering performance calculation unit, a turning radius adjustment unit, and an active suspension mode selection unit;

[0059] 2. The turning radius adjustment unit of the present invention is used to adjust the turning radius according to the vehicle's steering performance evaluation index Q. The turning radius adjustment unit is divided into a first-level turning radius adjustment unit, a second-level turning radius holding unit, and a third-level turning radius adjustment unit. When the vehicle is in the first-level steering mode, the turning radius adjustment unit executes the first-level turning radius adjustment unit. When the vehicle is in the second-level steering mode, the turning radius adjustment unit executes the second-level turning radius holding unit. When the vehicle is in the third-level steering mode, the turning radius adjustment unit executes the third-level turning radius adjustment unit.

[0060] 3. The active suspension mode selection unit of the present invention is used to select the corresponding active suspension adjustment mode according to the vehicle's steering mode. When the vehicle is in the first-level steering mode, the active suspension mode is the first-level adjustment mode, that is, to increase the roll stiffness of the suspension and increase the lateral adhesion of the tires. When the vehicle is in the second-level steering mode, the active suspension mode is the second-level holding mode, and the suspension does not make any adjustments. When the vehicle is in the third-level steering mode, the active suspension mode is the third-level adjustment mode, that is, to reduce the roll stiffness of the suspension and reduce the lateral adhesion of the tires, thereby ensuring the safety and comfort of the ride. Attached Figure Description

[0061] The present invention will be further described below with reference to the accompanying drawings:

[0062] Figure 1 This is a framework diagram of an integrated control system for steering and active suspension proposed in this invention. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] like Figure 1 As shown, the present invention is an integrated control system for a steering system and an active suspension, comprising: a sensor information acquisition unit, an information processing and central control unit, a steering performance calculation unit, a turning radius adjustment unit, and an active suspension mode selection unit;

[0065] The sensor information acquisition unit is used to collect basic data of the vehicle during driving, including vehicle speed sensor, body acceleration sensor, wheel acceleration sensor, yaw rate sensor, vehicle load sensor, turning radius sensor, and steering wheel angle sensor.

[0066] The information processing and central control unit is used to receive data collected from the sensor information acquisition unit, process the collected data and input it into the steering performance calculation unit and the active suspension mode selection unit, and send corresponding control commands to them.

[0067] The steering performance calculation unit is used to calculate the vehicle's steering performance, including:

[0068] S1. Establish a turning radius model for the vehicle when it turns. The turning radius R of the vehicle satisfies the following formula:

[0069]

[0070] Where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius in the direction of the vehicle.

[0071] S2. Calculate the various indicators of the steering system according to the following formulas, including:

[0072] S2.1 Calculate the tire condition index Q1 according to the following formula:

[0073]

[0074] Where α1, α2, and α3 are weighting coefficients, μ represents the tire's road adhesion coefficient (μ = 0.4 for wet roads, μ = 0.6 for wet cement roads, and μ = 0.8 for dry cement roads), q 11 This represents the vehicle load factor, the value of which depends on the vehicle's loading condition. When the vehicle is fully loaded, q... 11 =1.2, when the vehicle is half-loaded, q 11 =1.0, when the vehicle is unloaded, q 11 =0.8, q 12 q represents the tire pressure state coefficient. When the tire is a high-pressure tire, q 12 =1.5, when the tire is a low-pressure tire, q 12 =1.1, when the tire is an ultra-low pressure tire, q 12 =0.7, q 13 q represents the tire wear coefficient. When the tire is in a slightly worn state, q 13 =0.9, when the tire is in a state of moderate wear, q 13 =1.3, when the tire is in a severely worn state, q 13 =1.8, when the tires are not worn, q 13 =1.0, q 14 q represents the tire tread depth coefficient. When the tire tread depth is less than 3mm, q 14 =0.5, when the tire tread depth is 3-8mm, q 14 =0.7, when the tire tread depth is 8-10mm, q 14 =1.0, q 15 q represents the tire mass variation coefficient. When high-quality tires are used, q 15=2.0, q in other cases 15 =1.0;

[0075] S2.2 Calculate the tire process performance index Q2 according to the following formula:

[0076]

[0077] Where α4, α5, and α6 are weighting coefficients, τ represents the tire pass rate, which is equal to the ratio of the number of tires that meet the standards in the same batch of tires to the total number of tires inspected, and q 21 q represents the tire construction coefficient. When the tire used is a radial tire, q 21 =1.2, when the tires used are bias-ply tires, q 21 =0.9, q 22 q represents the tire tread pattern variation coefficient. When the tire tread pattern is a stripe pattern, q 22 =0.5, when the tire tread pattern is transverse, q 22 =0.6, when the tire tread pattern is a mixed pattern, q 22 =0.7, when the tire tread pattern is an off-road tread pattern, q 22 =0.8, q 23 q represents the tire performance factor, which indicates the tire's performance on muddy roads. 23 =0.7, when the tire is used on icy and snowy roads, q 23 =1.1, when the tire is used as a spare tire, q 23 =1.4, q in other cases 23 =1.0, q 24 q represents the tire wear performance coefficient. When a tire has good wear resistance, q is... 24 =2.0, when the tire does not have good wear resistance, q 24 =0.2, q 25 q represents the coefficient of variation in tire vulcanization processes. When a variable temperature vulcanization process is used for tires, q represents the coefficient of variation. 25 =1.3, when the tire uses injection molding, q 25 =1.4, when the tire uses nitrogen vulcanization process, q 25 =1.5, q 26 q represents the tire's dynamic performance coefficient, which depends on the tire's stability and grip during vehicle cornering. When the tire has good grip on a wet surface, q... 26 =0.9, when the tire has good grip on dry roads, q 26 =1.0, when the tire has good grip on icy and snowy roads, q 26 =1.6;

[0078] S2.3 Calculate the driver state sub-index Q3 during the steering process according to the following formula:

[0079]

[0080] Where α7, α8, and α9 are weighting coefficients, and q 31 q represents the driver's visual impact coefficient during turning, when there is a pedestrian in front of the vehicle. 31 =0.7, when there are other vehicles in front of the vehicle, q 31 =0.8, when there are other obstacles in front of the vehicle, q 31 =1.1, q 32 q represents the driver's physical condition coefficient; when the driver is steering while fatigued, q 32 =1.0, when the driver is turning while ill, q 32 =0.9, when the driver makes a turn while intoxicated, q 32 =0.5, q 33 This represents the driver's driving skill coefficient. When the driver's driving experience is less than or equal to 1 year, q 33 =0.2, when the driver's driving experience is greater than 1 year and less than 5 years, q 33 =0.6, when the driver's driving experience is greater than or equal to 5 years, q 33 =1.0, q 34 q represents the driver's age coefficient, which is set when the driver's age is greater than or equal to 18 years old and less than 35 years old. 34 =1.5, when the driver's age is greater than or equal to 35 years old and less than 55 years old, q 34 =1.4, when the driver's age is greater than or equal to 55 years old and less than 75 years old, q 34 =0.7, when the driver's age is greater than or equal to 75, q 34 =0.4, q 35 This represents the driver's reaction speed coefficient, the value of which depends on the driver's reaction time during a turn in case of an emergency, such as a sudden braking of the vehicle in front or a sudden change in traffic lights. When the driver's reaction time is less than or equal to 2 seconds, q... 35 =2.0, when the driver's reaction time is greater than 2 seconds and less than 5 seconds, q 35 =1.5, when the driver's reaction time is greater than or equal to 5 seconds, q 35 =1.0, q 36 This represents the driver's attention coefficient, q, when the driver makes or receives a phone call while turning. 36 =0.5, when the driver is fully focused on steering, q 36 =1.3, q in other cases 36 =0.8;

[0081] S2.4 Calculate the power steering fluid state index Q4 during the steering process using the following formula:

[0082]

[0083] Where, α 10 α 11 q is the weighting coefficient. 41 q represents the viscosity coefficient of the power steering fluid. 41 =0.5σ, where σ is the viscosity of the power steering fluid, σ = KωR 4 K represents the instrument constant of the rotational viscometer, ω is the rotational speed, R is the radius of the rotating cylinder, and q 42 q represents the power steering fluid moisture content coefficient. When the moisture content is less than or equal to 0.5%, q 42 =1.2, when the moisture content is greater than 0.5% and less than 1.0%, q 42 =0.9, when the moisture content is greater than or equal to 1.0%, q 42 =0.6, q 43 q represents the acid value coefficient of the power steering fluid. When the acid value of the power steering fluid is less than or equal to 0.1, q 43 =1.1, when the acid value of the power steering fluid is greater than 0.1 and less than 0.3, q 43 =0.8, when the acid value of the power steering fluid is greater than or equal to 0.3, q 43 =0.5, q 44 q represents the mechanical impurity coefficient of the power steering fluid. When impurities are present in the power steering fluid, q 44 =1.5, when there are no impurities in the power steering fluid, q 44 =0.2, q 45 q represents the pour point coefficient of the power steering fluid. When the pour point of the power steering fluid is less than or equal to -40℃, q 45 =1.4, when the pour point of the power steering fluid is greater than -40℃, q 45 =0.7, q 46 q represents the anti-foaming coefficient of power steering fluid. Its value depends on the height of the foam generated after stirring the power steering fluid and the foam dissipation time. When the foam height is less than or equal to 10 mm and the foam dissipation time is less than or equal to 15 seconds, q 46 =1.8, when the foam height is greater than 10mm and the foam dissipation time is greater than 15 seconds, q 46 =0.6;

[0084] S2.5 Calculate the steering column state sub-index Q5 during the steering process according to the following formula:

[0085]

[0086] Where, α12 and α 13 is the weight coefficient, and q 51 represents the material coefficient of the steering column. When the steering column is made of steel, q 51 = 0.7. When the steering column is made of aluminum alloy, q 51 = 0.9. When the steering column is made of composite material, q 51 = 1.1, and q 52 represents the adjustment method coefficient of the steering column. When the steering column is mechanically adjusted, q 52 = 0.8. When the steering column is electrically adjusted, q 52 = 1.2, and q 53 represents the wear degree coefficient of the steering column. When the steering column is slightly worn and does not affect vehicle steering, q<0000​​​​​​​​​​​​​​​​​​​​​​​​The turning radius adjustment unit is used to adjust the turning radius according to the steering performance evaluation index Q of the vehicle. The turning radius adjustment unit is divided into a primary turning radius adjustment unit, a secondary turning radius maintenance unit, and a tertiary turning radius adjustment unit. When the vehicle is in the primary steering mode, the turning radius adjustment unit executes the primary turning radius adjustment unit. When the vehicle is in the secondary steering mode, the turning radius adjustment unit executes the secondary turning radius maintenance unit. When the vehicle is in the tertiary steering mode, the turning radius adjustment unit executes the tertiary turning radius adjustment unit;

[0092] When the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the turning radius adjustment unit does not work;

[0093] When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the turning radius adjustment unit executes the primary turning radius adjustment unit, and the turning radius R1 of the vehicle satisfies the following formula:

[0094]

[0095] where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction;

[0096] When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the turning radius adjustment unit executes the secondary turning radius maintenance unit, and the turning radius is not adjusted;

[0097] When the steering performance evaluation index Q satisfies δ3 < Q < 1, the turning radius adjustment unit executes the tertiary turning radius adjustment unit, and the turning radius R3 of the vehicle satisfies the following formula:

[0098] <00​​​​​​​​​​​​​​Among them, C is the roll stiffness of the suspension, C s is the spring stiffness, C Lsb is the stiffness of the anti-roll bar, k 11 is the suspension structure coefficient. When the suspension is an air suspension, k 11 = 0.6. When the suspension is a hydraulic suspension, k 11 = 0.7. When the suspension is an electromagnetic suspension, k 11 = 0.8. When the suspension is an electro-hydraulic suspension, k 11 = 0.9, B is the wheelbase, m is the offset of spring arrangement, n is a coefficient related to the vehicle structure, and its value is determined by the actual vehicle structure;

[0104] The lateral adhesion force F of the tire y satisfies the following formula:

[0105] F y = μF z q 13

[0106] Among them, F y is the lateral adhesion force of the tire, μ is the road adhesion coefficient of the tire, F z is the normal load of the tire, q 13 is the tire wear degree coefficient;

[0107] When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the active suspension mode selection unit executes the first-level adjustment mode, and the roll stiffness C1 of the suspension satisfies the following formula:

[0108]

[0109] The lateral adhesion force F of the tire y1 satisfies the following formula:

[0110]

[0111] When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the active suspension mode selection unit executes the second-level holding mode, and the suspension is not adjusted;

[0112] When the steering performance evaluation index Q satisfies δ3 < Q < 1, the active suspension mode selection unit executes the third-level adjustment mode, and the roll stiffness C2 of the suspension satisfies the following formula:

[0113]

[0114] The lateral adhesion force F of the tire y2 satisfies the following formula:

[0115]

[0116] When the steering performance evaluation index Q satisfies 0

Claims

1. An integrated control system for a steering system and an active suspension, characterized in that, It includes the following: sensor information acquisition unit, information processing and central control unit, steering performance calculation unit, turning radius adjustment unit, active suspension mode selection unit; The sensor information acquisition unit is used to collect the basic data of the vehicle during driving, including vehicle speed sensor, body acceleration sensor, wheel acceleration sensor, yaw rate sensor, vehicle load sensor, turning radius sensor, steering wheel angle sensor; The information processing and central control unit is used to receive the data collected by the sensor information acquisition unit, process the collected data and input it into the steering performance calculation unit and the active suspension mode selection unit, and at the same time send corresponding control instructions to them; The steering performance calculation unit is used to calculate the steering performance of the vehicle, including: S1. Establish a turning radius model when the vehicle steers. The turning radius R of the vehicle satisfies the following formula: where R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction; S2. Calculate each index of the steering system according to the following formula, including: S2.

1. Calculate the tire state sub-index Q1 according to the following formula: Where α1, α2, and α3 are weighting coefficients, μ represents the tire's road adhesion coefficient (μ = 0.4 for wet roads, μ = 0.6 for wet cement roads, and μ = 0.8 for dry cement roads), q 11 This represents the vehicle load factor, the value of which depends on the vehicle's loading condition. When the vehicle is fully loaded, q... 11 =1.2, when the vehicle is half-loaded, q 11 =1.0, when the vehicle is unloaded, q 11 =0.8, q 12 q represents the tire pressure state coefficient. When the tire is a high-pressure tire, q 12 =1.5, when the tire is a low-pressure tire, q 12 =1.1, when the tire is an ultra-low pressure tire, q 12 =0.7, q 13 q represents the tire wear coefficient. When the tire is in a slightly worn state, q 13 =0.9, when the tire is in a state of moderate wear, q 13 =1.3, when the tire is in a severely worn state, q 13 =1.8, when the tires are not worn, q 13 =1.0, q 14 q represents the tire tread depth coefficient. When the tire tread depth is less than 3mm, q 14 =0.5, when the tire tread depth is 3-8mm, q 14 =0.7, when the tire tread depth is 8-10mm, q 14 =1.0, q 15 q represents the tire mass variation coefficient. When high-quality tires are used, q 15 =2.0, q in other cases 15 =1.0; S2.

2. Calculate the tire process performance sub-index Q2 according to the following formula: Where α4, α5, and α6 are weighting coefficients, τ represents the tire pass rate, which is equal to the ratio of the number of tires that meet the standards in the same batch of tires to the total number of tires inspected, and q 21 q represents the tire construction coefficient. When the tire used is a radial tire, q 21 =1.2, when the tires used are bias-ply tires, q 21 =0.9, q 22 q represents the tire tread pattern variation coefficient. When the tire tread pattern is a stripe pattern, q 22 =0.5, when the tire tread pattern is transverse, q 22 =0.6, when the tire tread pattern is a mixed pattern, q 22 =0.7, when the tire tread pattern is an off-road tread pattern, q 22 =0.8, q 23 q represents the tire performance factor, which indicates the tire's performance on muddy roads. 23 =0.7, when the tire is used on icy and snowy roads, q 23 =1.1, when the tire is used as a spare tire, q 23 =1.4, q in other cases 23 =1.0, q 24 q represents the tire wear performance coefficient. When a tire has good wear resistance, q is... 24 =2.0, when the tire does not have good wear resistance, q 24 =0.2, q 25 q represents the coefficient of variation in tire vulcanization processes. When a variable temperature vulcanization process is used for tires, q represents the coefficient of variation. 25 =1.3, when the tire uses injection molding, q 25 =1.4, when the tire uses nitrogen vulcanization process, q 25 =1.5, q 26 q represents the tire's dynamic performance coefficient, which depends on the tire's stability and grip during vehicle cornering. When the tire has good grip on a wet surface, q... 26 =0.9, when the tire has good grip on dry roads, q 26 =1.0, when the tire has good grip on icy and snowy roads, q 26 =1.6; S2.

3. Calculate the driver state sub-index Q3 during steering according to the following formula: Where α7, α8, and α9 are weighting coefficients, and q 31 q represents the driver's visual impact coefficient during turning, when there is a pedestrian in front of the vehicle. 31 =0.7, when there are other vehicles in front of the vehicle, q 31 =0.8, when there are other obstacles in front of the vehicle, q 31 =1.1, q 32 q represents the driver's physical condition coefficient; when the driver is steering while fatigued, q 32 =1.0, when the driver is turning while ill, q 32 =0.9, when the driver makes a turn while intoxicated, q 32 =0.5, q 33 This represents the driver's driving skill coefficient. When the driver's driving experience is less than or equal to 1 year, q 33 =0.2, when the driver's driving experience is greater than 1 year and less than 5 years, q 33 =0.6, when the driver's driving experience is greater than or equal to 5 years, q 33 =1.0, q 34 q represents the driver's age coefficient, which is set when the driver's age is greater than or equal to 18 years old and less than 35 years old. 34 =1.5, when the driver's age is greater than or equal to 35 years old and less than 55 years old, q 34 =1.4, when the driver's age is greater than or equal to 55 years old and less than 75 years old, q 34 =0.7, when the driver's age is greater than or equal to 75, q 34 =0.4, q 35 This represents the driver's reaction speed coefficient, the value of which depends on the driver's reaction time during a turn in case of an emergency, such as a sudden braking of the vehicle in front or a sudden change in traffic lights. When the driver's reaction time is less than or equal to 2 seconds, q... 35 =2.0, when the driver's reaction time is greater than 2 seconds and less than 5 seconds, q 35 =1.5, when the driver's reaction time is greater than or equal to 5 seconds, q 35 =1.0, q 36 This represents the driver's attention coefficient, q, when the driver makes or receives a phone call while turning. 36 =0.5, when the driver is fully focused on steering, q 36 =1.3, q in other cases 36 =0.8; S2.

4. Calculate the power steering fluid state sub-index Q4 during steering according to the following formula: Where, α 10 α 11 q is the weighting coefficient. 41 q represents the viscosity coefficient of the power steering fluid. 41 =0.5σ, where σ is the viscosity of the power steering fluid, σ = KωR 4 K represents the instrument constant of the rotational viscometer, ω is the rotational speed, R is the radius of the rotating cylinder, and q 42 q represents the power steering fluid moisture content coefficient. When the moisture content is less than or equal to 0.5%, q 42 =1.2, when the moisture content is greater than 0.5% and less than 1.0%, q 42 =0.9, when the moisture content is greater than or equal to 1.0%, q 42 =0.6, q 43 q represents the acid value coefficient of the power steering fluid. When the acid value of the power steering fluid is less than or equal to 0.1, q 43 =1.1, when the acid value of the power steering fluid is greater than 0.1 and less than 0.3, q 43 =0.8, when the acid value of the power steering fluid is greater than or equal to 0.3, q 43 =0.5, q 44 q represents the mechanical impurity coefficient of the power steering fluid. When impurities are present in the power steering fluid, q 44 =1.5, when there are no impurities in the power steering fluid, q 44 =0.2, q 45 q represents the pour point coefficient of the power steering fluid. When the pour point of the power steering fluid is less than or equal to -40℃, q 45 =1.4, when the pour point of the power steering fluid is greater than -40℃, q 45 =0.7, q 46 q represents the anti-foaming coefficient of power steering fluid. Its value depends on the height of the foam generated after stirring the power steering fluid and the foam dissipation time. When the foam height is less than or equal to 10 mm and the foam dissipation time is less than or equal to 15 seconds, q 46 =1.8, when the foam height is greater than 10mm and the foam dissipation time is greater than 15 seconds, q 46 =0.6; S2.

5. Calculate the steering column state sub-index Q5 during steering according to the following formula: Where, α 12 α 13 q is the weighting coefficient. 51 q represents the material coefficient of the steering column. When the steering column is made of steel, q 51 =0.7, when the steering column is made of aluminum alloy, q 51 =0.9, when the steering column is made of composite material, q 51 =1.1, q 52 This represents the adjustment method coefficient of the steering column. When the steering column is mechanically adjustable, q 52 =0.8, when the steering column is electrically adjustable, q 52 =1.2, q 53 q represents the wear coefficient of the steering column. When the steering column is only slightly worn and does not affect vehicle steering, q represents the wear coefficient. 53 =0.5, when severe wear of the steering column causes steering insensitivity, q 53 =1.5, q 54 q represents the lubricant coefficient of the steering column. When gear oil is used as the lubricant in the steering column, q 54 =0.3, when the steering column uses engine oil as the lubricant, q 54 =0.6, when the steering column uses a special steering fluid, q 54 =1.0; S3. Calculate the steering performance evaluation index Q according to the following formula: where γ1, γ2, γ3, γ4, γ5 are the weighted values for calculating single indexes.

2. The integrated control system for a steering system and an active suspension according to claim 1, characterized in that, According to the magnitude of the steering performance evaluation index Q, the vehicle steering can be divided into first-level steering mode, second-level steering mode, and third-level steering mode. Among them, both the first-level steering mode and the third-level steering mode are unsatisfactory steering modes, and the second-level steering mode is an ideal steering mode. By introducing the first-level steering mode decision threshold δ1, the second-level steering mode decision threshold δ2, and the third-level steering mode decision threshold δ3, it is determined which steering mode the vehicle belongs to when steering. Among them, 0 < δ1 < δ2 < δ3 < 1; when the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the vehicle does not steer; when the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the vehicle steering mode is the first-level steering mode; when the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the vehicle steering mode is the second-level steering mode; when the steering performance evaluation index Q satisfies δ3 < Q < 1, the vehicle steering mode is the third-level steering mode.

3. The integrated control system for a steering system and an active suspension according to claim 1, characterized in that, The turning radius adjustment unit is used to adjust the turning radius according to the steering performance evaluation index Q of the vehicle. The turning radius adjustment unit is divided into a primary turning radius adjustment unit, a secondary turning radius maintenance unit, and a tertiary turning radius adjustment unit. When the vehicle is in the primary steering mode, the turning radius adjustment unit executes the primary turning radius adjustment unit. When the vehicle is in the secondary steering mode, the turning radius adjustment unit executes the secondary turning radius maintenance unit. When the vehicle is in the tertiary steering mode, the turning radius adjustment unit executes the tertiary turning radius adjustment unit; When the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the turning radius adjustment unit does not work; When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the turning radius adjustment unit executes the primary turning radius adjustment unit, and the turning radius R1 of the vehicle satisfies the following formula: Where, R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction; When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the turning radius adjustment unit executes the secondary turning radius maintenance unit, and the turning radius is not adjusted; When the steering performance evaluation index Q satisfies δ3 < Q < 1, the turning radius adjustment unit executes the tertiary turning radius adjustment unit, and the turning radius R3 of the vehicle satisfies the following formula: Where, R is the turning radius of the vehicle, L is the length of the vehicle body, and ψ is the minimum turning radius of the vehicle direction.

4. The integrated control system for a steering system and an active suspension according to claim 1, characterized in that, The active suspension mode selection unit is used to select the corresponding active suspension adjustment mode according to the steering mode of the vehicle. When the vehicle is in the primary steering mode, the mode of the active suspension is the primary adjustment mode, that is, to increase the roll stiffness of the suspension and increase the lateral adhesion of the tire. When the vehicle is in the secondary steering mode, the mode of the active suspension is the secondary maintenance mode, and the suspension is not adjusted. When the vehicle is in the tertiary steering mode, the mode of the active suspension is the tertiary adjustment mode, that is, to reduce the roll stiffness of the suspension and reduce the lateral adhesion of the tire; The roll stiffness C of the suspension satisfies the following formula: Where C is the roll stiffness of the suspension, C s For the spring stiffness, C Lsb For the lateral stabilizer stiffness, k 11 k is the suspension structure coefficient; when the suspension is an air suspension, k 11 =0.6, when the suspension is a hydraulic suspension, k 11 =0.7, when the suspension is an electromagnetic suspension, k 11 =0.8, when the suspension is an electro-hydraulic suspension, k 11 =0.9, B is the wheelbase, m is the spring arrangement offset, and n is a coefficient related to the vehicle structure, the value of which depends on the actual vehicle structure; Lateral adhesion force F of the tire y Satisfy the following formula: F y =μF z q 13 Among them, F y F represents the lateral adhesion force of the tire, μ is the tire's coefficient of friction against the road surface, and F is the lateral adhesion force of the tire. z Let q be the normal load on the tire. 13 This is the tire wear coefficient.

5. The integrated control system for a steering system and an active suspension according to claim 1, characterized in that, When the steering performance evaluation index Q satisfies δ1 < Q ≤ δ2, the active suspension mode selection unit executes the primary adjustment mode, and the roll stiffness C1 of the suspension satisfies the following formula: Lateral adhesion force F of the tire y1 Satisfy the following formula: When the steering performance evaluation index Q satisfies δ2 < Q ≤ δ3, the active suspension mode selection unit executes the secondary maintenance mode, and the suspension is not adjusted; When the steering performance evaluation index Q satisfies δ3 < Q < 1, the active suspension mode selection unit executes the tertiary adjustment mode, and the roll stiffness C2 of the suspension satisfies the following formula: Lateral adhesion force F of the tire y2 Satisfy the following formula: When the steering performance evaluation index Q satisfies 0 < Q ≤ δ1, the active suspension mode selection unit does not work.

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