A control method and system of an external variable damping electromagnetic valve of a vehicle shock absorber

Abstract

This invention relates to a control method and system for an externally mounted variable damping solenoid valve for vehicle shock absorbers, belonging to the field of automotive shock absorber control technology. The method includes: acquiring the vehicle's current location; determining the region type and forward road segment in the driving direction based on the current location and an onboard map; searching for a corresponding predicted distance in a type distance database based on the region type; dividing the forward road segment along the driving direction from the current location according to the predicted distance to obtain a predicted road segment, and searching for the road parameters of the predicted road segment from the onboard map; searching for the corresponding damping condition in a road condition database based on the road parameters; before the vehicle enters the predicted road segment, if the damping condition is low, de-energizing the solenoid valve; if the damping condition is medium, supplying a low current to the solenoid valve; and if the damping condition is high, supplying a high current to the solenoid valve. This invention has the effect of quickly matching the corresponding damping gear for different road conditions.

Description

Technical Field

[0001] This invention relates to the field of automotive shock absorption control technology, and in particular to a control method and system for an externally mounted variable damping solenoid valve for a vehicle shock absorber. Background Technology

[0002] An externally mounted variable damping solenoid valve is located outside the shock absorber. It controls the valve core opening via an electrical signal, changing the oil flow resistance and thus adjusting the damping. This type of solenoid valve is compact, has a fast response time, and is easy to assemble and maintain. It is a core component in vehicle electronically controlled shock absorber systems for achieving variable damping adjustment.

[0003] Currently, variable damping solenoid valves generally adopt a passive response control mode. The system collects vehicle state parameters such as vehicle vibration, vehicle speed and steering posture in real time, and dynamically adjusts the output current of the solenoid valve based on the real-time monitoring results to achieve real-time matching of damping. Some solutions combine the feedback signal of the shock absorber to perform auxiliary correction of damping.

[0004] Regarding the aforementioned technologies, existing shock absorption systems equipped with variable damping solenoid valves have limited graded adjustment capabilities and struggle to quickly match corresponding damping levels for different road conditions, leaving room for improvement. Summary of the Invention

[0005] To quickly match the corresponding damping gear for different road conditions, this invention provides a control method, system, and intelligent terminal for an external variable damping solenoid valve for vehicle shock absorbers.

[0006] In a first aspect, the present invention provides a control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber, employing the following technical solution: A control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber includes: Step S1: Obtain the vehicle's current location; Step S2: Determine the area type and the forward road segment in the direction of travel based on the current location and the preset vehicle map; Step S3: Based on the region type, search for the corresponding predicted distance in the preset type distance library; Step S4: On the road ahead, starting from the current location, divide the road into predicted segments along the driving direction according to the predicted distance, and find the road parameters of the predicted road segments from the vehicle map; Step S5: Search for the corresponding damping condition in the preset road condition database according to the road parameters. The damping conditions include low damping condition, medium damping condition and high damping condition. Step S50: Before the vehicle enters the predicted road section, if the damping condition is low damping, control the solenoid valve to de-energize, so that the vehicle is in a low damping state. Step S51: If the damping condition is medium damping condition, control the solenoid valve to supply a low current so that the vehicle is in a medium damping state. Step S52: If the damping condition is high damping condition, control the solenoid valve to supply high current so that the vehicle is in a high damping state.

[0007] By adopting the above technical solution, the current location of the vehicle is obtained, and the corresponding area type and the road segment ahead are determined by combining the vehicle map; the predicted distance is obtained by looking up a table based on the area type, the predicted road segment is extracted and the road parameters are extracted; three damping conditions of low, medium and high are obtained by matching the road parameters. Before the vehicle enters the predicted road segment, the solenoid valve is de-energized, low current is applied and high current is applied respectively, which solves the problem of difficulty in quickly matching the corresponding damping gear for different road conditions and achieves the effect of matching the corresponding damping gear in advance according to the predicted road information.

[0008] Optionally, it also includes an analysis method for predicting road segments, which includes: Step S40: If the current location falls into the predicted road segment, obtain the feedback pressure inside the shock absorber; Step S41: Analyze the feedback pressure to obtain pressure characteristics, and find the road condition parameters corresponding to the pressure characteristics in the preset pressure road condition database; Step S42: Road parameters include road condition parameters. Search for the actual damping condition corresponding to the road condition parameter in the road condition database. Step S43: If the actual damping condition is inconsistent with the damping condition, switch the damping condition to the actual damping condition and output it.

[0009] By adopting the above technical solution, the shock absorber feedback pressure is collected after the vehicle enters the predicted road section. The pressure characteristics are analyzed and the road condition parameters are obtained by looking up the table. The actual damping condition is obtained by matching the road condition parameters. When the predicted damping condition is inconsistent with the actual damping condition, the output is switched to the actual damping condition. This solves the problem that the predicted damping condition does not match the actual road condition and realizes the effect of adjusting the damping condition in real time by using feedback pressure.

[0010] Optional, also includes: Step S60: Obtain the front wheel feedback pressure and corresponding feedback time inside the vehicle's front wheel shock absorber; Step S61: Analyze the front wheel feedback pressure to obtain the front wheel pressure characteristics, and find the front wheel road condition parameters corresponding to the front wheel pressure characteristics in the pressure road condition database; Step S62: Based on the front wheel road condition parameters, search for the corresponding front wheel damping condition in the road condition database; Step S63: Obtain the current vehicle speed, and calculate the time difference between the front and rear wheels passing the same road surface position based on the current vehicle speed and the preset vehicle wheelbase; Step S64: Subtract the preset response time from the sum of the feedback time and the time difference to obtain the rear wheel switching time; Step S65: During the rear wheel switching time, control the solenoid valve corresponding to the rear wheel to switch the damping mode to the front wheel damping mode.

[0011] By adopting the above technical solution, the front wheel feedback pressure and feedback time of the front wheel shock absorber are collected. After analyzing the front wheel pressure characteristics, the front wheel road condition parameters are obtained by looking up the table, and the front wheel damping condition is matched. Combining the current vehicle speed and the vehicle wheelbase, the time difference between the front and rear wheels traveling on the same road surface is calculated, and the rear wheel switching time is calculated. At the rear wheel switching time, the damping condition of the rear wheel solenoid valve is switched to the front wheel damping condition. This solves the problem of inconsistent damping conditions between the front and rear wheels when passing the same road surface, and realizes the effect of using front wheel data to support the adjustment of the rear wheels.

[0012] Optionally, during the rear wheel switching time, the method of controlling the damping condition of the solenoid valve corresponding to the rear wheel to switch to the front wheel damping condition also includes: Step S650: Obtain the steering wheel angle; Step S651: If the steering wheel angle falls within the preset turning angle range, calculate the turning direction based on the steering wheel angle; Step S652: Define the front wheel opposite to the turning direction as the turning front wheel, define the rear wheel on the same side as the turning front wheel as the turning rear wheel, and define the front wheel feedback pressure inside the turning front wheel shock absorber as the turning feedback pressure; Step S653: Analyze the turning feedback pressure to obtain the turning pressure characteristics, and find the turning road condition parameters corresponding to the turning pressure characteristics in the pressure road condition database; Step S654: Search for the corresponding turning damping condition in the road condition database based on the turning road condition parameters; Step S655: During the rear wheel switching time, control the solenoid valve corresponding to the turning rear wheel to switch the damping mode to the turning damping mode.

[0013] By adopting the above technical solution, the steering wheel angle is collected. If the steering wheel angle is within the preset turning angle range, the turning direction is determined and the turning front wheel, turning rear wheel, and turning feedback pressure are defined. The turning feedback pressure is analyzed to obtain the turning pressure characteristics. The turning road condition parameters are obtained by querying the pressure road condition database. Then, the turning damping condition is obtained by matching the road condition database. Finally, at the rear wheel switching time, the solenoid valve corresponding to the turning rear wheel is controlled to switch to the turning damping condition. This solves the problem of unpredictable rear wheel damping condition during turning and achieves the effect of using the data of the front wheel on the same side to support the adjustment of the rear wheel damping condition.

[0014] Optional, also includes: Step S44: When the actual damping condition is inconsistent with the damping condition, accumulate the duration of inconsistency; Step S45: When the actual damping condition matches the damping condition, stop accumulating the duration of inconsistency; Step S46: Obtain the current vehicle speed, and calculate the inconsistency distance based on the inconsistency duration and the current vehicle speed; Step S47: If the inconsistency distance is greater than the preset distance threshold, the predicted road segment corresponding to the inconsistency distance is defined as a long-term road segment. Step S48: Use the actual damping condition as the damping condition for the long-term road section.

[0015] By adopting the above technical solution, the inconsistency time is accumulated when the actual damping condition is inconsistent with the actual damping condition, and the accumulation of inconsistency time stops when the two are consistent. The inconsistency distance is calculated by combining the current vehicle speed and the inconsistency time. When the inconsistency distance is greater than the preset distance threshold, the corresponding predicted road segment is designated as a long-term road segment, and the actual damping condition is set as the damping condition of the long-term road segment. This solves the problem of long-distance discrepancies between the predicted damping condition and the actual detected damping condition, and achieves the effect of correcting the damping condition when there is an anomaly over a long distance.

[0016] Optionally, methods for using the actual damping condition as the damping condition for long-term road sections include: Step S480: If the current location falls into a long-term road section again, execute steps S40 to S42 to calculate the actual damping conditions. Step S481: If the actual damping condition is still inconsistent with the damping condition, update the road condition parameters corresponding to the long-term road section to the vehicle map. Step S482: Use the actual damping condition as the damping condition for the long-term road section.

[0017] By adopting the above technical solution, when the current location falls into the long-term road section again, the actual damping condition is recalculated. If the actual damping condition is still inconsistent with the actual damping condition, the road condition parameters corresponding to the long-term road section are updated to the vehicle map, and the actual damping condition is set as the damping condition of the long-term road section. This solves the problem of the damping condition not matching the actual condition due to the vehicle map data not being updated in real time, and achieves the effect of updating map data according to the actual feedback pressure.

[0018] Optionally, it also includes a processing method for if the inconsistency distance is not greater than a preset distance threshold, the method comprising: Step S470: Define the predicted road segment corresponding to the inconsistent distance as a short-term road segment; Step S471: Generate short-term markers based on short-term road segments and corresponding road condition parameters, and accumulate the generation time starting from the generation time of the short-term markers; Step S472: If the generation duration is less than the preset effective duration and the current location falls into a short-term road segment again, the damping condition corresponding to the short-term marker shall be used first. Step S473: If the generation duration is not less than the preset effective duration, clear the short-term marker.

[0019] By adopting the above technical solution, the corresponding predicted road segment is designated as a short-term road segment. Short-term markers are generated based on the short-term road segment and its road condition parameters, and the generation time is accumulated. When the generation time has not reached the effective time, the damping condition corresponding to the short-term marker is used first when entering the short-term road segment again. If the generation time exceeds the effective time, the short-term marker is cleared. This solves the problem that the predicted damping condition does not match the actual damping condition due to short-term anomalies and achieves the effect of short-term correction of damping condition.

[0020] Optionally, methods for searching for the corresponding damping condition in a preset road condition database based on road parameters include: Step S70: Find the speed limit information for the predicted road segment in the vehicle map; Step S71: Estimate the vehicle's speed based on the speed limit information; Step S72: Define the damping condition obtained from the road condition database based on the road parameters as the first damping condition; Step S73: Search for the corresponding second damping condition in the preset speed damping library according to the driving speed; Step S74: If the first damping condition is the same as the second damping condition, then control the solenoid valve according to the damping condition. Step S75: If the first damping condition and the second damping condition are inconsistent, select the higher damping condition from the first damping condition and the comparison damping condition, and control the solenoid valve according to the comparison damping condition.

[0021] By adopting the above technical solution, the speed limit information of the predicted road section is retrieved to infer the driving speed. The damping condition obtained by matching the road parameters is recorded as the first damping condition. Then, the second damping condition is obtained by looking up the table through the driving speed. If the two are consistent, the solenoid valve is directly controlled by the damping condition. If the two are inconsistent, the comparative damping control solenoid valve with higher damping is selected. This solves the problem that the damping condition does not match the demand due to the failure to consider the vehicle driving speed. It achieves the effect of combining driving speed and road parameters to determine the required damping condition.

[0022] Optionally, a method for updating the driving speed is also included, which includes: Step S710: Obtain congestion information for the predicted road segment; Step S711: Analyze the congestion information to obtain the congestion level; Step S712: Search for the corresponding congestion speed in the preset congestion speed database based on the congestion level; Step S713: When the congestion speed is lower than the driving speed, update the driving speed to the congestion speed.

[0023] By adopting the above technical solution, congestion information of the predicted road segment is obtained and the congestion level is analyzed. The congestion speed is obtained by looking up the table according to the congestion level. When the congestion speed is less than the driving speed, the driving speed is updated to the congestion speed. This solves the problem of abnormal prediction damping conditions caused by road congestion and changes in driving speed, and achieves the effect of predicting vehicle driving speed in combination with the degree of road congestion.

[0024] Secondly, the present invention provides a control system for an externally mounted variable damping solenoid valve for a vehicle shock absorber, employing the following technical solution: A control system for an externally mounted variable damping solenoid valve for a vehicle shock absorber, comprising: The acquisition module is used to acquire current location, feedback pressure, front wheel feedback pressure, feedback time, current vehicle speed, steering wheel angle, and congestion information; The memory is used to store the program for the control method of the external variable damping solenoid valve of a vehicle shock absorber as described above. The processor loads and executes programs from memory.

[0025] In summary, the present invention has at least one of the following beneficial technical effects: It solves the problem of difficulty in quickly matching the corresponding damping gear for different road conditions, and achieves the effect of predicting road information and matching the corresponding damping gear in advance; This solves the problem that the predicted damping conditions do not match the actual road conditions, and achieves the effect of adjusting the damping conditions in real time using feedback pressure. It solves the problem of inconsistent damping conditions between the front and rear wheels when passing through the same road surface, and achieves the effect of using front wheel data to support rear wheel adjustments. Attached Figure Description

[0026] Figure 1 This is a flowchart of a control method for an external variable damping solenoid valve for a vehicle shock absorber according to an embodiment of this application; Figure 2 This is a schematic diagram of the external variable damping solenoid valve for a vehicle shock absorber according to an embodiment of this application. Figure 3 This is an exploded view of a component of an externally mounted variable damping solenoid valve for a vehicle shock absorber, as described in an embodiment of this application.

[0027] The parts referred to by the numbers in the above attached diagrams are as follows: 1. First sealing ring; 2. End cap; 3. Washer; 4. Pilot seat; 5. Large spring; 6. Irregular spring; 7. Flow stop; 8. Small spring; 9. Float; 10. Valve body; 11. Base; 12. Upper guide sleeve; 13. Second sealing ring; 14. Housing; 15. Push rod; 16. Valve core; 17. Third sealing ring; 18. Cage; 19. Fourth sealing ring; 20. Lower guide sleeve; 21. Yoke sleeve; 22. Fifth sealing ring; 23. Sixth sealing ring; 24. Coil. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0029] This invention discloses a control method for an externally mounted variable damping solenoid valve in a vehicle shock absorber. (Refer to...) Figure 1 A control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber includes: Step S1: Obtain the vehicle's current location.

[0030] Current positioning refers to the real-time coordinates of the vehicle's location while it is in motion. Current positioning is provided in real-time by the vehicle's GPS, with an update frequency of no less than 1Hz. Inertial navigation data can be fused as needed to ensure positioning continuity in areas with weak signals, such as tunnels or urban canyons.

[0031] Step S2: Determine the area type and the forward road segment in the direction of travel based on the current location and the preset vehicle map.

[0032] In-vehicle maps refer to digital road databases pre-stored in vehicle navigation systems, including but not limited to: road classification, road surface type, road condition status, road geometry, speed limit information, and area type (such as highways, urban roads, mountain roads, tunnels, etc.). In-vehicle maps are pre-installed by those skilled in the art when the vehicle leaves the factory and are subsequently updated online through the in-vehicle navigation system.

[0033] The area type refers to the environmental type of the area where the vehicle is traveling on. The area type is automatically determined by the onboard map based on the current location and includes at least: highways, urban arterial roads, ordinary roads, mountain roads, and tunnels.

[0034] The direction of travel refers to the direction a vehicle is moving along the road at the current moment, usually expressed as an angle relative to geographic north (heading angle) or relative to the centerline of the road. The direction of travel is determined by the heading angle output by GPS or the positional changes of continuous positioning points.

[0035] The forward route refers to the road segment that extends from the current location along the vehicle's direction of travel until the end of the current road or the next key node in the map's road network. The forward route is dynamically generated by the in-vehicle map based on the current location and direction of travel, extending along the vehicle's direction of travel to the current road's exit, intersection, or road grade change point.

[0036] Step S3: Based on the region type, search for the corresponding predicted distance in the preset type distance library.

[0037] The type distance database stores a mapping relationship between region types and their corresponding predicted distances, pre-set by those skilled in the art. First, based on the typical vehicle speed and system response time (0.5 to 1.0 seconds) for each region type, combined with positioning error compensation (approximately 50 to 100 meters), an initial theoretical predicted distance is calculated. Then, during the real-vehicle calibration phase, the predicted distance is tested and adjusted on different road sections for each region type, using the criterion that "the solenoid valve has completed its state switch before the vehicle enters the point of road condition change" to determine the final distance. Finally, the final distance is stored in the type distance database as a one-to-one correspondence between predicted distances and region types. Regions with higher vehicle speeds and requiring earlier responses have larger predicted distances; regions with lower vehicle speeds, simpler road conditions, or limited space have appropriately shorter predicted distances. For example, the predicted distance for highways is 400 meters, for urban expressways it is 200 meters, for urban arterial roads it is 120 meters, for ordinary roads it is 60 meters, for mountain roads it is 100 meters, and for tunnels it is 50 meters.

[0038] The predicted distance refers to the predicted length extending forward along the road segment from the current location point. The predicted distance is obtained by looking up a table in the type distance database for the current area type and is used to determine the length of the predicted road segment.

[0039] Step S4: On the road ahead, the predicted road segment is obtained by dividing the road along the driving direction from the current location according to the predicted distance, and the road parameters of the predicted road segment are found from the vehicle map.

[0040] The predicted road segment refers to the section of road taken from the current location along the direction of travel, with a length equal to the predicted distance. If the predicted distance exceeds the remaining length of the previous road segment, the end of that previous road segment is taken as the end of the predicted road segment.

[0041] Road parameters are a set of specific data describing the road conditions of a predicted road segment. These parameters are provided by the in-vehicle map for the predicted road segment and include at least one or more of the following: road class, road surface type, road condition, and geometric features.

[0042] Step S5: Based on the road parameters, search for the corresponding damping condition in the preset road condition database. The damping conditions include low damping condition, medium damping condition and high damping condition.

[0043] The road condition database contains a mapping relationship between road parameters and damping conditions, which is pre-set by those skilled in the art. First, the input parameters of the road condition database, i.e., the road parameters, are determined. In this embodiment, the road parameters include four dimensions: road grade, pavement type, road condition state, and geometric features. The road condition state is divided into three levels: smooth, moderate undulation, and bumpy; the geometric features are divided into straight, curved, and uphill / downhill sections. Second, the damping condition output definition is established: low damping corresponds to the solenoid valve being de-energized (current is 0A), medium damping corresponds to a low current (0.3 to 0.8A), and high damping corresponds to a high current (1.2 to 1.8A). The specific values ​​are determined based on the electromagnetic force and damping output characteristics of the solenoid valve. Then, mapping rules are formulated. Based on the road condition state: smooth pavements are matched with low damping, moderate undulation pavements with medium damping, and bumpy pavements with high damping. On this basis, adjustments are made according to other road parameters: damping can be appropriately reduced in highway scenarios, appropriately increased in curved or slope scenarios, and medium damping or higher is mandatory for gravel pavements. Finally, the mapping rules were verified and adjusted through real-vehicle calibration. Damping response was tested in various typical scenarios (high-speed cruising, urban roads, mountain curves, gravel roads, tunnels, and downhill slopes, etc.). The mapping relationship was fine-tuned based on subjective comfort and handling stability evaluations to obtain the final road condition database. The worse the road conditions and the greater the impact, the higher the damping; the better the road conditions and the smoother the surface, the lower the damping.

[0044] Damping conditions refer to the operating state of the solenoid valve, which has three levels: low damping, medium damping, and high damping. The damping condition is obtained by matching road parameters in a road condition database.

[0045] Low damping operation refers to the operating state where the shock absorber provides low damping force. In this state, the suspension is relatively soft, prioritizing ride comfort. Medium damping operation refers to the operating state where the shock absorber provides moderate damping force. In this state, the suspension stiffness is between low and high damping, balancing comfort and handling stability. High damping operation refers to the operating state where the shock absorber provides high damping force. In this state, the suspension is relatively stiff, prioritizing vehicle stability and handling.

[0046] Step S50: Before the vehicle enters the predicted road section, if the damping condition is low damping, de-energize the solenoid valve to put the vehicle in a low damping state.

[0047] Reference Figure 2 and Figure 3An external variable damping solenoid valve for a vehicle shock absorber includes: a first sealing ring 1, an end cap 2, a washer 3, a pilot seat 4, a large spring 5, a shaped spring 6, a flow resistor 7, a small spring 8, a float 9, a valve body 10, a base 11, an upper guide sleeve 12, a second sealing ring 13, a housing 14, a push rod 15, a valve core 16, a third sealing ring 17, a retainer 18, a fourth sealing ring 19, a lower guide sleeve 20, a yoke sleeve 21, a fifth sealing ring 22, a sixth sealing ring 23, and a coil 24.

[0048] In the initial state, the oil in the lower chamber of the shock absorber piston enters the solenoid valve through the central hole of the solenoid valve end cover 2. The pilot seat 4 is pressed against the end cover 2 by the spring force of the large spring 5. The oil pressure in the lower chamber of the shock absorber piston pushes it open to the left by different distances. The greater the oil pressure, the greater the opening distance, and feedback different opening degrees. The oil can be discharged from the gap. At this time, the damping provided is low. Another part of the oil can enter the inner side through the small central hole of the pilot seat 4. The oil can pass through the flow resistor 7 and the float 9 and then be discharged from the side of the valve body 10. The flow resistor 7 is provided with several throttling orifices. At this time, the damping provided is low. The discharged oil goes to the upper chamber of the shock absorber piston to complete the oil circulation. At this time, the solenoid valve is in the state corresponding to the low damping condition, that is, the low damping state.

[0049] In the low-current state, the coil 24 of the solenoid valve receives an electrical signal and generates a magnetic field. Under the action of the magnetic field, the valve core 16 generates a thrust to the right. The valve core 16 pushes the float 9 to overcome the elastic force of the small spring 8, reducing the distance between it and the flow resistor 7. The closer this distance is, the greater the damping of the oil through the flow resistor 7, thereby achieving damping adjustment within a small range. In this state, the oil can still be discharged through the gap between the pilot seat 4 and the end cover 2, ensuring basic flow. At this time, the solenoid valve is in the state corresponding to the medium-damping condition, that is, the medium-damping state.

[0050] Under high current conditions, the coil 24 of the solenoid valve receives a higher electrical signal, generating a stronger magnetic field. The valve core 16 generates a greater thrust, which also overcomes the elastic force of the irregularly shaped spring 6 and the large spring 5. The pilot seat 4 is pushed against the end cover 2 with a greater thrust. The lower chamber oil pressure of the piston needs to be higher to push the pilot seat 4. Under low oil pressure, the oil cannot flow easily, thus it is in a high-damping state for regulation. At this time, the solenoid valve is in the state corresponding to the high-damping working condition, that is, the high-damping state.

[0051] Before the vehicle enters the predicted road segment, it refers to the moment when the distance between the vehicle's current position and the starting point of the predicted road segment is less than a preset execution threshold. The execution threshold is used to trigger the actual switching action of the solenoid valve, and its specific value can be dynamically adjusted according to the vehicle speed and system response time, as long as it is ensured that the solenoid valve completes the state switching before the vehicle actually enters the predicted road segment, for example, 10 meters to 30 meters.

[0052] If the damping condition is low before the vehicle enters the predicted road section, it means that the predicted road section ahead is a flat and smooth road condition, and the vehicle does not need high damping force to maintain vehicle stability. At this time, the control solenoid valve is de-energized to put the vehicle in a low damping state.

[0053] Step S51: If the damping condition is medium damping, control the solenoid valve to supply a low current so that the vehicle is in a medium damping state.

[0054] Before the vehicle enters the predicted road section, if the damping condition is medium damping, it means that the predicted road section ahead has moderate undulations or slight curves. The vehicle needs appropriate suspension support to ensure vehicle stability and maintain a certain level of comfort. At this time, the control solenoid valve is supplied with a low current to put the vehicle in a medium damping state.

[0055] Step S52: If the damping condition is high damping condition, control the solenoid valve to supply high current so that the vehicle is in a high damping state.

[0056] If the damping condition is high before the vehicle enters the predicted road section, it means that the predicted road section ahead is a bumpy road, gravel road, continuous curves or road conditions with a large slope. The vehicle needs high damping force to maintain vehicle stability and handling safety. At this time, the control solenoid valve is supplied with high current to put the vehicle in a high damping state.

[0057] This also includes an analysis method for predicting road segments, which includes: Step S40: If the current location falls into the predicted road segment, obtain the feedback pressure inside the shock absorber.

[0058] Feedback pressure refers to the real-time pressure value generated by the fluid inside the shock absorber during vehicle operation. This pressure value varies with the magnitude of road impacts on the wheels; the bumpier the road, the greater the pressure, and the smoother the road, the lower the pressure. Feedback pressure is obtained in real-time by a pressure sensor installed inside the shock absorber, which can be a piezoresistive or capacitive pressure sensor.

[0059] If the current location falls into the predicted road segment, it means that the vehicle has entered the predicted road segment and is driving on the predicted road segment. At this time, feedback pressure is obtained, and the actual smoothness of the road surface can be monitored in real time. Subsequently, the current of the solenoid valve can be adjusted according to the feedback pressure.

[0060] Step S41: Analyze the feedback pressure to obtain pressure characteristics, and find the road condition parameters corresponding to the pressure characteristics in the preset pressure road condition database.

[0061] Pressure characteristics refer to the features extracted from feedback pressure that reflect the road surface condition. Specifically, the root mean square (RMS) pressure value is used as the pressure characteristic. A sliding window process is applied to the feedback pressure, with a window length of 0.5 seconds. The RMS pressure value is calculated within each window and used as the pressure characteristic for that moment. This characteristic value reflects the combined impact of road surface irregularities on the shock absorber. In addition to the RMS value, peak pressure or pressure change rate can also be used as supplementary features as needed.

[0062] The pressure road condition database contains a mapping relationship between pressure characteristics and road condition parameters. Established by experts through real-vehicle testing, the database first selects three typical road surfaces: smooth asphalt road, moderately undulating cement road, and bumpy gravel road. The internal pressure of the shock absorbers is collected when vehicles travel on these three road surfaces, and the root mean square (RMS) pressure value is calculated. Three threshold values ​​are defined based on these RMS pressure values ​​for the three typical road surfaces. For example, a RMS pressure value less than 0.5 MPa corresponds to a smooth road surface, 0.5 MPa to 1.2 MPa corresponds to a moderately undulating road surface, and greater than 1.2 MPa corresponds to a bumpy road surface. These threshold values ​​can be adjusted according to vehicle model and shock absorber characteristics.

[0063] Road condition parameters are indicators describing the smoothness of road surfaces, categorized into three levels: smooth, moderately undulating, and bumpy. The calculated pressure characteristics are input into a pressure road condition database, and the current road condition parameters are obtained by looking up tables. The road condition parameters output by the pressure road condition database are essentially the road condition status from the road parameters section.

[0064] Step S42: Road parameters include road condition parameters. Search for the actual damping condition corresponding to the road condition parameter in the road condition database.

[0065] The actual damping condition refers to the damping condition matched from the road condition database based on the current actual road conditions. After obtaining the road condition status (smooth, moderately undulating, or bumpy) based on the feedback pressure, this value is used as one of the inputs to the road condition database. The road condition database has preset mapping rules based on road condition status: low damping condition is matched when the road condition status is smooth, medium damping condition is matched when the road condition status is moderately undulating, and high damping condition is matched when the road condition status is bumpy. Other road parameters (such as road grade, pavement type, and geometric features) can be set to default values ​​or use the values ​​predicted from the map in this step.

[0066] Step S43: If the actual damping condition is inconsistent with the damping condition, switch the damping condition to the actual damping condition and output it.

[0067] If the actual damping condition is inconsistent with the damping condition, it means that the road condition parameters detected by the feedback pressure are inconsistent with the road condition status in the vehicle map road parameters. This may be due to changes in the road surface caused by years of rolling or changes in some road sections due to construction. In this case, switch the damping condition to the actual damping condition and use the current state corresponding to the actual damping condition to control the solenoid valve to execute according to the corresponding current state.

[0068] This also includes: Step S60: Obtain the front wheel feedback pressure and corresponding feedback time inside the vehicle's front wheel shock absorber.

[0069] Front wheel feedback pressure refers to the real-time pressure value generated by the fluid inside the front wheel shock absorbers during vehicle operation. The front wheel feedback pressure is obtained in real-time by pressure sensors installed inside the front wheel shock absorbers.

[0070] Feedback time refers to the system time corresponding to the acquisition of front wheel feedback pressure, which is obtained by reading the system clock time when the front wheel feedback pressure is acquired.

[0071] Step S61: Analyze the front wheel feedback pressure to obtain the front wheel pressure characteristics, and find the front wheel road condition parameters corresponding to the front wheel pressure characteristics in the pressure road condition database.

[0072] Front wheel pressure characteristics refer to the features extracted from the front wheel feedback pressure that reflect the road surface conditions traversed by the front wheels. The method for obtaining front wheel pressure characteristics is the same as that in step S41.

[0073] Front wheel road condition parameters are indicators describing the smoothness of the road surface traversed by the front wheels, and are divided into three levels: smooth road surface, moderately undulating road surface, and bumpy road surface. Front wheel road condition parameters are obtained by searching a pressure road condition database based on front wheel pressure characteristics.

[0074] Step S62: Based on the front wheel road condition parameters, search for the corresponding front wheel damping condition in the road condition database.

[0075] The front wheel damping condition refers to the damping condition matched from the road condition database based on the front wheel road condition parameters. This condition represents the optimal damping setting when the front wheels pass over this road surface location.

[0076] Step S63: Obtain the current vehicle speed, and calculate the time difference between the front and rear wheels passing the same road surface position based on the current vehicle speed and the preset vehicle wheelbase.

[0077] Current vehicle speed refers to the current speed of the vehicle, which is obtained by reading the vehicle's wheel speed sensors.

[0078] The wheelbase of a vehicle is the straight-line distance between the center of the front axle and the center of the rear axle. It is a fixed dimensional parameter of the vehicle and is calibrated when the vehicle leaves the factory.

[0079] The time difference refers to the time interval between the front and rear wheels passing the same point on the road surface. The time difference is equal to the vehicle's wheelbase divided by its current speed.

[0080] Step S64: Subtract the preset response time from the sum of the feedback time and the time difference to obtain the rear wheel switching time.

[0081] Response time refers to the total time required from the moment the front wheel feedback pressure is collected until the rear wheel solenoid valve actually begins to execute its action. This includes, but is not limited to, the pressure sensor sampling time, control unit processing time, communication transmission time, and solenoid valve response time. The total duration of these components is the response time, which is typically between 50 and 100 milliseconds. The specific value can be confirmed through testing during vehicle calibration: under calibration conditions, pressure signals and solenoid valve drive current are simultaneously collected, and the time difference between the peak value of the pressure signal and the rising edge of the solenoid valve current is measured.

[0082] The rear wheel switching time refers to the moment when the rear wheel solenoid valve issues a control switching command. The rear wheel switching time equals the feedback time plus the time difference, minus the response time.

[0083] Step S65: During the rear wheel switching time, control the solenoid valve corresponding to the rear wheel to switch the damping mode to the front wheel damping mode.

[0084] When the rear wheel switching time is reached, it means that the current system time has reached the moment to send a control switching command to the rear wheel solenoid valve. Therefore, the damping condition of the solenoid valve corresponding to the rear wheel is switched to the damping condition of the front wheel. This means that when the rear wheel reaches the same road surface position passed by the front wheel, the solenoid valve of the rear wheel is adjusted to the optimal damping state.

[0085] The method for switching the damping mode of the solenoid valve corresponding to the rear wheel to the front wheel damping mode during the rear wheel switching time also includes: Step S650: Obtain the steering wheel angle.

[0086] Steering wheel angle refers to the angle the steering wheel turns from the center position (straight-line driving position). The steering wheel angle is detected by a non-contact angle sensor (such as Hall effect or photoelectric type) installed on the steering column. The angle is negative when turning left and positive when turning right.

[0087] Step S651: If the steering wheel angle falls within the preset turning angle range, calculate the turning direction based on the steering wheel angle.

[0088] The turning angle range refers to the angle used to determine whether a vehicle is actually turning, and is preset by those skilled in the art. In this embodiment, the turning angle range is defined as an absolute value greater than or equal to 10 degrees. When the absolute value of the steering wheel angle is greater than or equal to 10 degrees, the vehicle is determined to be turning; when the absolute value of the steering wheel angle is less than 10 degrees, it is determined to be driving in a straight line or making minor directional adjustments.

[0089] The turning direction refers to whether the vehicle turns left or right, which can be determined directly by the sign (positive or negative) of the steering wheel angle.

[0090] If the steering wheel angle falls within the preset turning angle range, it means that the vehicle is turning. First, determine the turning direction based on the steering wheel angle.

[0091] Step S652: Define the front wheel opposite to the turning direction as the turning front wheel, define the rear wheel on the same side as the turning front wheel as the turning rear wheel, and define the front wheel feedback pressure inside the turning front wheel shock absorber as the turning feedback pressure.

[0092] Step S653: Analyze the turning feedback pressure to obtain the turning pressure characteristics, and find the turning road condition parameters corresponding to the turning pressure characteristics in the pressure road condition database.

[0093] The turning pressure characteristic refers to the root mean square value extracted from the turning feedback pressure. The method of obtaining the pressure characteristic is the same as that in step S41.

[0094] Turning road condition parameters refer to the road surface grade obtained by looking up a table in the pressure road condition database based on turning pressure characteristics. When establishing the pressure road condition database, curves are treated as a separate operating condition for data collection, selecting three typical road surfaces: smooth asphalt road, moderately undulating concrete road, and bumpy gravel road. On each road surface, vehicles are driven at different speeds (30km / h, 40km / h, 50km / h) and a fixed turning radius (e.g., 50 meters), and the pressure signal of the outer front wheel shock absorber is collected, extracting the root mean square (RMS) value of the pressure. Three threshold values ​​are defined based on the RMS values ​​of the three typical road surfaces. For example, a RMS value less than 0.7MPa corresponds to a smooth road surface, 0.7MPa to 1.5MPa corresponds to a moderately undulating road surface, and greater than 1.5MPa corresponds to a bumpy road surface. These threshold values ​​can be adjusted according to vehicle type and shock absorber characteristics, and the straight-ahead threshold or the curve threshold is selected for table lookup depending on whether the vehicle is currently turning.

[0095] Step S654: Based on the turning road condition parameters, search for the turning damping condition corresponding to the turning road condition parameters in the road condition database.

[0096] The cornering damping condition refers to the damping condition matched from a road condition database based on cornering road condition parameters. In the road condition database, separate mapping rules are set for cornering scenarios: a medium-damping condition is matched when the cornering road condition parameters are a smooth surface; a high-damping condition is matched when the cornering road condition parameters are a moderately undulating surface; and a high-damping condition is matched when the cornering road condition parameters are a bumpy surface. These mapping rules are used to suppress vehicle roll. These mapping rules can be optimized based on real-vehicle test results.

[0097] Step S655: During the rear wheel switching time, control the solenoid valve corresponding to the turning rear wheel to switch the damping mode to the turning damping mode.

[0098] When the rear wheel switching time is reached, it means that the current system time has reached the moment when the control switching command is sent to the rear wheel solenoid valve. The rear wheel reaches the same turning surface position that the front wheel has passed through during the entire turning process. Therefore, the damping mode of the solenoid valve corresponding to the turning rear wheel is switched to the turning damping mode.

[0099] This also includes: Step S44: When the actual damping condition is inconsistent with the damping condition, accumulate the duration of inconsistency.

[0100] Inconsistency duration refers to the time between when the actual damping condition and the damping condition predicted by the map begin to differ and then return to the same state. The inconsistency duration is accumulated by the system clock when the actual damping condition and the predicted damping condition become inconsistent, and accumulation stops when they become consistent. After each inconsistency ends, the previously accumulated duration is reset to zero, and accumulation restarts for the next inconsistency.

[0101] When the actual damping condition is inconsistent with the actual damping condition, it indicates that the description of the road section by the vehicle map deviates from the actual road conditions or that the road conditions have temporarily changed. At this point, the duration of inconsistency begins to accumulate.

[0102] Step S45: When the actual damping condition is consistent with the damping condition, stop accumulating the duration of inconsistency.

[0103] When the actual damping condition matches the actual damping condition, it means that the description of the road segment by the vehicle map is consistent with the actual road conditions. At this point, the accumulation of the inconsistency duration is stopped, and the final inconsistency duration is obtained.

[0104] Step S46: Obtain the current vehicle speed and calculate the inconsistency distance based on the inconsistency duration and the current vehicle speed.

[0105] Inconsistency distance refers to the distance a vehicle travels while in an inconsistent state. First, calculate the average speed during the inconsistency period based on the current speed. Multiply the average speed by the inconsistency period to obtain the inconsistency distance. For greater precision, divide the inconsistency period into smaller segments, calculate the distance for each segment using the current speed, and then sum them up to obtain the inconsistency distance.

[0106] Step S47: If the inconsistency distance is greater than the preset distance threshold, the predicted road segment corresponding to the inconsistency distance is defined as a long-term road segment.

[0107] The distance threshold is a defined value used to determine whether an inconsistency distance is a random deviation. This threshold is determined by those skilled in the art through real-vehicle testing. First, sections of road where map data deviates from actual road conditions are identified in the vehicle map. The distance at which the driver experiences a decrease in comfort due to damping mismatch is observed. In this embodiment, 100 meters is used as the distance threshold.

[0108] Long-term road sections refer to road sections where there is a significant distance deviation between the damping conditions predicted by the map and the actual required damping conditions.

[0109] If the inconsistency distance is greater than the preset distance threshold, it indicates that the map data for the predicted road segment is not accurate enough. Therefore, the predicted road segment corresponding to the inconsistency distance is defined as a long-term road segment.

[0110] Step S48: Use the actual damping condition as the damping condition for the long-term road section.

[0111] The actual damping condition is updated to the damping condition of the long-term road section. At this time, the damping condition is a damping gear that has been actually verified and is applicable to the long-term road section.

[0112] The methods for using actual damping conditions as damping conditions for long-term road sections include: Step S480: If the current location falls into a long-term road section again, execute steps S40 to S42 to calculate the actual damping conditions.

[0113] If the current location falls into a long-term road section again, it means that the vehicle has entered the long-term road section it has passed through before. At this time, steps S40 to S42 are executed again to calculate the actual damping condition to determine whether the actual condition is consistent with the prediction.

[0114] Step S481: If the actual damping condition is still inconsistent with the damping condition, update the road condition parameters corresponding to the long-term road section to the vehicle map.

[0115] If the actual damping condition is still inconsistent with the actual damping condition, it means that there is still a difference between the road parameters in the vehicle map and the actual condition of the long-term road section. Therefore, the road condition parameters corresponding to the long-term road section are updated to the vehicle map. When passing through the long-term road section again, the applicable damping condition can be found directly based on the actual road condition parameters.

[0116] If the actual damping condition matches the actual damping condition, it means that the road parameters in the vehicle map for the long-term road section are consistent with the actual condition, and no additional operation is required.

[0117] Step S482: Use the actual damping condition as the damping condition for the long-term road section.

[0118] This also includes a method for handling situations where the inconsistency distance is not greater than a preset distance threshold, the method comprising: Step S470: Define the predicted road segment corresponding to the inconsistent distance as a short-term road segment.

[0119] Short-term road sections refer to road sections where the actual damping conditions do not match the predicted damping conditions, but the discrepancy is short. These sections are usually caused by temporary changes in road conditions, such as a pothole, a section of construction or repair, or temporary water accumulation on the road surface, and are not due to problems with the vehicle map data itself.

[0120] Step S471: Generate short-term markers based on short-term road segments and the corresponding road condition parameters, and accumulate the generation time starting from the generation time of the short-term markers.

[0121] Short-term markers refer to temporary records generated for short-term road segments, which include the following information: short-term road segment location information (starting point coordinates and ending point coordinates), road condition parameters corresponding to the short-term road segment, and actual damping conditions.

[0122] The generation duration refers to the length of time elapsed from the time the short-term tag was generated to the current time. The generation duration is the length of time elapsed from the time the short-term tag was generated until the current time, calculated by the system clock.

[0123] Step S472: If the generation duration is less than the preset effective duration and the current location falls into a short-term road segment again, the damping condition corresponding to the short-term marker shall be used first.

[0124] The validity period refers to the longest valid time of a short-term marker, which is preset by those skilled in the art, such as 24 hours.

[0125] If the generation time is less than the preset effective time and the current location falls into the short-term road segment again, it means that the short-term marker is still valid. When the vehicle passes through the short-term road segment again, the damping condition in the short-term marker is used first to control the solenoid valve current.

[0126] Step S473: If the generation duration is not less than the preset effective duration, clear the short-term marker.

[0127] If the generation time is not less than the preset valid time, it means that the short-term marker has expired. At this time, the short-term marker is cleared, and regular prediction and real-time feedback pressure are used to control the solenoid valve current.

[0128] The methods for finding the corresponding damping condition in a preset road condition database based on road parameters include: Step S70: Find the speed limit information for the predicted road segment in the vehicle map.

[0129] Speed ​​limit information refers to the predicted maximum permissible speed for vehicles on a road segment. The speed limit attribute value for that road segment is retrieved from the in-vehicle map based on the predicted road segment's location information; this is the speed limit information. Speed ​​limit information is not part of the aforementioned road parameters but rather an independent information source.

[0130] Step S71: Estimate the vehicle's speed based on the speed limit information.

[0131] Driving speed refers to the speed at which a vehicle may travel on this road segment. Driving speed is obtained by multiplying the speed limit by a preset speed coefficient, which is adjusted according to road type and driving mode: 0.9 for highways, 0.8 for urban roads, and 0.7 for mountain roads; a higher value is used in Sport mode, and a lower value is used in Eco mode. This embodiment defaults to 0.8, meaning the driving speed equals the product of the speed limit and 0.8.

[0132] Step S72: Define the damping condition obtained from the road condition database based on the road parameters as the first damping condition.

[0133] Step S73: Search for the corresponding second damping condition in the preset speed damping library according to the driving speed.

[0134] The speed-damping library stores a mapping relationship between driving speed and damping conditions. Higher speeds indicate better road conditions, requiring low damping; lower speeds indicate more complex or bumpier road conditions, requiring high damping. The speed-damping library is established by first testing different speeds on typical road sections to determine the most suitable damping, recording the results to form the mapping relationship. For example: speeds greater than 60 km / h are matched with low damping conditions; speeds between 30 km / h and 60 km / h are matched with medium damping conditions; and speeds less than or equal to 30 km / h are matched with high damping conditions. These speed thresholds can be adjusted through actual vehicle calibration.

[0135] The second damping condition refers to the damping condition obtained by matching the driving speed in the speed damping library.

[0136] Step S74: If the first damping condition is the same as the second damping condition, then control the solenoid valve according to the damping condition.

[0137] If the first damping condition is consistent with the second damping condition, it means that the damping condition predicted based on road parameters is consistent with the damping condition preset based on driving speed. In this case, the interference of damping control corresponding to vehicle speed can be eliminated, and the solenoid valve current can be directly controlled by the damping condition predicted based on road parameters.

[0138] Step S75: If the first damping condition and the second damping condition are inconsistent, select the higher damping condition from the first damping condition and the comparison damping condition, and control the solenoid valve according to the comparison damping condition.

[0139] Comparative damping refers to the damping condition selected from the first and second damping conditions when they are inconsistent. The damping rating of the first and second damping conditions is compared, and the one with the higher damping rating is the comparative damping.

[0140] If the first damping condition is inconsistent with the second damping condition, it means that the damping condition predicted based on road parameters is inconsistent with the damping condition preset based on driving speed. In this case, directly using the damping condition predicted by road parameters may be affected by vehicle speed and cannot accurately control the solenoid valve current. Therefore, the comparison damping with high damping is selected. High damping corresponds to a more conservative and safer control strategy, so the solenoid valve current is controlled according to the comparison damping.

[0141] This also includes a method for updating driving speed, which includes: Step S710: Obtain congestion information for the predicted road segment.

[0142] Congestion information refers to real-time data describing the degree of traffic congestion on the road ahead, obtained from the real-time traffic service of the vehicle navigation system.

[0143] Step S711: Analyze the congestion information to obtain the congestion level.

[0144] Congestion level refers to the result of quantifying and classifying congestion information. Congestion information is converted into a congestion level according to preset classification rules. In this embodiment, the congestion level is divided into four levels: smooth traffic, slow traffic, congested traffic, and severe congestion. The classification rules refer to the following: average vehicle speed greater than 40 km / h or traffic speed greater than 60% of the speed limit is smooth traffic; average vehicle speed 20 to 40 km / h or traffic speed 30% to 60% of the speed limit is slow traffic; average vehicle speed 10 to 20 km / h or traffic speed 10% to 30% of the speed limit is congested traffic; average vehicle speed less than 10 km / h or traffic speed less than 10% of the speed limit is severe congestion.

[0145] Step S712: Search for the corresponding congestion speed in the preset level speed library based on the congestion level.

[0146] The congestion level database contains a mapping relationship between congestion levels and corresponding congestion speeds. This database is pre-set by those skilled in the art; specifically, it sets a congestion coefficient or speed for each congestion level. The congestion speed is obtained by multiplying the predicted speed limit of the road segment by the congestion coefficient corresponding to the congestion level. For example, the congestion coefficient for smooth traffic is 0.8 (corresponding to a speed of at least 40 km / h), for slow traffic it is 0.4 (corresponding to a speed of at least 20 km / h), for congested traffic it is 0.15 (corresponding to a speed of at least 10 km / h), and for severe congestion it is 5 km / h. These congestion coefficients or speeds can be adjusted based on actual vehicle conditions; different vehicle models or driving modes can use different values.

[0147] Congestion speed refers to the estimated vehicle speed calculated based on the congestion level, which is obtained by looking up the speed in the congestion level database.

[0148] Step S713: When the congestion speed is lower than the driving speed, update the driving speed to the congestion speed.

[0149] When the congestion speed is lower than the driving speed, it indicates that there is real congestion in the predicted road segment, and the actual speed of the vehicle will be lower than the predicted speed limit. At this time, the driving speed is updated to the congestion speed.

[0150] When the congestion speed is not lower than the driving speed, it means that the speed indicated by the congestion information is not lower than the current estimated speed. The congestion information may be outdated or the congestion level may be relatively mild. In this case, the original driving speed is maintained and no update is performed.

[0151] Based on the same inventive concept, embodiments of the present invention provide a control system for an externally mounted variable damping solenoid valve for a vehicle shock absorber.

[0152] A control system for an externally mounted variable damping solenoid valve for a vehicle shock absorber, comprising: The acquisition module is used to acquire current location, feedback pressure, front wheel feedback pressure, feedback time, current vehicle speed, steering wheel angle, and congestion information; The memory stores a computer program that can be loaded by a processor and executed to control a method for an externally mounted variable damping solenoid valve for a vehicle shock absorber. The processor loads and executes programs from memory.

[0153] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0154] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber, characterized in that, include: Step S1: Obtain the vehicle's current location; Step S2: Determine the area type and the forward road segment in the direction of travel based on the current location and the preset vehicle map; Step S3: Based on the region type, search for the corresponding predicted distance in the preset type distance library; Step S4: On the road ahead, starting from the current location, divide the road into predicted segments along the driving direction according to the predicted distance, and find the road parameters of the predicted segments from the vehicle map; Step S5: Search for the corresponding damping condition in the preset road condition database according to the road parameters. The damping conditions include low damping condition, medium damping condition and high damping condition. Step S50: Before the vehicle enters the predicted road section, if the damping condition is low damping, control the solenoid valve to de-energize, so that the vehicle is in a low damping state. Step S51: If the damping condition is medium damping condition, control the solenoid valve to supply a low current so that the vehicle is in a medium damping state. Step S52: If the damping condition is high damping condition, control the solenoid valve to supply high current so that the vehicle is in a high damping state.

2. The control method for an external variable damping solenoid valve for a vehicle shock absorber according to claim 1, characterized in that, It also includes analysis methods for predicting road segments, which include: Step S40: If the current location falls into the predicted road segment, obtain the feedback pressure inside the shock absorber; Step S41: Analyze the feedback pressure to obtain pressure characteristics, and find the corresponding road condition parameters in the preset pressure road condition database; Step S42: Road parameters include road condition parameters. Search for the actual damping condition corresponding to the road condition parameter in the road condition database. Step S43: If the actual damping condition is inconsistent with the damping condition, switch the damping condition to the actual damping condition and output it.

3. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 2, characterized in that, Also includes: Step S60: Obtain the front wheel feedback pressure and corresponding feedback time inside the vehicle's front wheel shock absorber; Step S61: Analyze the front wheel feedback pressure to obtain the front wheel pressure characteristics, and find the front wheel road condition parameters corresponding to the front wheel pressure characteristics in the pressure road condition database; Step S62: Based on the front wheel road condition parameters, search for the corresponding front wheel damping condition in the road condition database; Step S63: Obtain the current vehicle speed, and calculate the time difference between the front and rear wheels passing the same road surface position based on the current vehicle speed and the preset vehicle wheelbase; Step S64: Subtract the preset response time from the sum of the feedback time and the time difference to obtain the rear wheel switching time; Step S65: During the rear wheel switching time, control the solenoid valve corresponding to the rear wheel to switch the damping mode to the front wheel damping mode.

4. The control method for an external variable damping solenoid valve for a vehicle shock absorber according to claim 3, characterized in that, During the rear wheel switching time, the method for controlling the solenoid valve corresponding to the rear wheel to switch from the front wheel damping condition also includes: Step S650: Obtain the steering wheel angle; Step S651: If the steering wheel angle falls within the preset turning angle range, calculate the turning direction based on the steering wheel angle; Step S652: Define the front wheel opposite to the turning direction as the turning front wheel, define the rear wheel on the same side as the turning front wheel as the turning rear wheel, and define the front wheel feedback pressure inside the turning front wheel shock absorber as the turning feedback pressure; Step S653: Analyze the turning feedback pressure to obtain the turning pressure characteristics, and find the turning road condition parameters corresponding to the turning pressure characteristics in the pressure road condition database; Step S654: Search for the corresponding turning damping condition in the road condition database based on the turning road condition parameters; Step S655: During the rear wheel switching time, control the solenoid valve corresponding to the turning rear wheel to switch the damping mode to the turning damping mode.

5. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 2, characterized in that, Also includes: Step S44: When the actual damping condition is inconsistent with the damping condition, accumulate the duration of inconsistency; Step S45: When the actual damping condition matches the damping condition, stop accumulating the duration of inconsistency; Step S46: Obtain the current vehicle speed, and calculate the inconsistency distance based on the inconsistency duration and the current vehicle speed; Step S47: If the inconsistency distance is greater than the preset distance threshold, the predicted road segment corresponding to the inconsistency distance is defined as a long-term road segment. Step S48: Use the actual damping condition as the damping condition for the long-term road section.

6. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 5, characterized in that, Methods for using actual damping conditions as damping conditions for long-term road sections include: Step S480: If the current location falls into a long-term road section again, execute steps S40 to S42 to calculate the actual damping conditions. Step S481: If the actual damping condition is still inconsistent with the damping condition, update the road condition parameters corresponding to the long-term road section to the vehicle map. Step S482: Use the actual damping condition as the damping condition for the long-term road section.

7. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 5, characterized in that, It also includes a method for handling situations where the inconsistency distance is not greater than a preset distance threshold, the method comprising: Step S470: Define the predicted road segment corresponding to the inconsistent distance as a short-term road segment; Step S471: Generate short-term markers based on short-term road segments and corresponding road condition parameters, and accumulate the generation time starting from the generation time of the short-term markers; Step S472: If the generation duration is less than the preset effective duration and the current location falls into a short-term road segment again, the damping condition corresponding to the short-term marker shall be used first. Step S473: If the generation duration is not less than the preset effective duration, clear the short-term marker.

8. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 1, characterized in that, The methods for finding the corresponding damping condition in a preset road condition database based on road parameters include: Step S70: Find the speed limit information for the predicted road segment in the vehicle map; Step S71: Estimate the vehicle's speed based on the speed limit information; Step S72: Define the damping condition obtained from the road condition database based on the road parameters as the first damping condition; Step S73: Search for the corresponding second damping condition in the preset speed damping library according to the driving speed; Step S74: If the first damping condition is the same as the second damping condition, then control the solenoid valve according to the damping condition. Step S75: If the first damping condition and the second damping condition are inconsistent, select the higher damping condition from the first damping condition and the comparison damping condition, and control the solenoid valve according to the comparison damping condition.

9. The control method for an externally mounted variable damping solenoid valve for a vehicle shock absorber according to claim 8, characterized in that, It also includes a method for updating driving speed, which includes: Step S710: Obtain congestion information for the predicted road segment; Step S711: Analyze the congestion information to obtain the congestion level; Step S712: Search for the corresponding congestion speed in the preset congestion speed database based on the congestion level; Step S713: When the congestion speed is lower than the driving speed, update the driving speed to the congestion speed.

10. A control system for an externally mounted variable damping solenoid valve for a vehicle shock absorber, characterized in that, include: The acquisition module is used to acquire current location, feedback pressure, front wheel feedback pressure, feedback time, current vehicle speed, steering wheel angle, and congestion information; A memory for storing a program for a control method of an external variable damping solenoid valve for a vehicle shock absorber as described in any one of claims 1 to 9; The processor loads and executes programs from memory.

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