Piston pump type hydraulic active suspension system, method and vehicle

Abstract

The present application relates to the technical fields of hydraulic active suspension, and discloses a piston pump type hydraulic active suspension system, method and vehicle, which comprises a power assembly, a damper assembly and an accumulator, a valve control oil circuit is arranged on the damper assembly, an electromagnetic valve is arranged on the valve control oil circuit, and the damper assembly is connected with the accumulator through the valve control oil circuit; the power assembly is a piston pump assembly, the piston pump assembly is connected with the damper assembly through a pump control oil circuit, and the valve control oil circuit and the pump control oil circuit are arranged in parallel; the piston pump is used as a power source, the sealing performance of the piston pump is excellent, internal leakage is extremely small, and the volumetric efficiency and total efficiency are significantly higher than those of a traditional involute hydraulic gear pump.

Description

Technical Field

[0001] This invention relates to the field of hydraulic active suspension technology, and in particular to a piston pump type hydraulic active suspension system, method and vehicle. Background Technology

[0002] The suspension system is a core component of the car chassis, directly determining the vehicle's ride comfort, handling stability, braking safety, and passability. It is the core carrier for balancing ride comfort and chassis dynamic performance.

[0003] Existing hydraulic active suspension pumps are all involute gear type, relying on a pair of meshing involute gears rotating within a closed pump body. The pump body is divided into suction and discharge zones. In the suction zone, the meshing volume increases as the gears disengage, creating a vacuum to draw in oil. In the discharge zone, the meshing volume decreases, expelling the oil, thus achieving flow control. However, involute hydraulic gear pumps always suffer from internal leakage, and this leakage increases with increasing pressure, leading to a decrease in operating pressure and consequently, reduced volumetric and overall efficiency, making them ineffective in handling special operating conditions. Furthermore, the periodic gear meshing of involute hydraulic gear pumps easily causes pulsations in output flow and pressure, generating significant noise, especially under high pressure and high speed conditions. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a piston pump type hydraulic active suspension system, method and vehicle to solve the above problems.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, a piston pump type hydraulic active suspension system includes a powertrain, a damper assembly, and an accumulator. The damper assembly is provided with a valve control oil circuit, and a solenoid valve is provided on the valve control oil circuit. The damper assembly is connected to the accumulator through the valve control oil circuit. The powertrain is a piston pump assembly, and the piston pump assembly is connected to the damper assembly through a pump control oil circuit. The valve control oil circuit and the pump control oil circuit are arranged in parallel.

[0006] As a further implementation, the piston pump assembly includes a piston pump connected to a motor, which is controlled by a controller MCU.

[0007] As a further implementation, the piston pump is a bidirectional variable pump, the pump control oil circuit is a hydraulic line, and the piston pump is connected to the upper and lower chambers of the damper assembly through the hydraulic line to form a closed loop.

[0008] As a further implementation, the solenoid valves are respectively compression solenoid valves and reset solenoid valves in different valve control oil circuits, and the solenoid valves are all proportional solenoid directional valves.

[0009] As a further implementation, the pump-controlled oil circuit is the main oil circuit. The opening of the solenoid valve is adjusted by different currents to change the flow rate of the main oil circuit, thereby changing the pressure difference between the upper and lower chambers of the damper assembly.

[0010] As a further implementation, the piston pump assembly adopts a three-in-one design, consisting of a pump head, a piston pump body, and a controller.

[0011] As a further implementation, the piston pump assembly adopts a five-in-one approach, consisting of two pump heads, two piston pump bodies, and a controller.

[0012] Secondly, a method for operating a piston pump type hydraulic active suspension system, employing any of the active suspension systems described above, includes the following steps: Under valve control, the oil flow rate in the main oil circuit is adjusted by controlling the opening of the solenoid valve in the damper assembly with different currents, thereby changing the pressure difference between the upper and lower chambers of the damper. At this time, the piston pump assembly automatically adjusts the output according to the load. In pump control mode, the piston pump assembly controls the main oil circuit flow rate by rotating at a certain speed. It can also automatically adjust the internal swashplate or swing angle according to the load to achieve stepless adjustment of the main oil circuit flow rate. The accumulator adapts to the system oil pressure.

[0013] As a further implementation method, it is divided into active control mode and semi-active control mode; In active mode, the piston pump assembly actively performs work and adaptively adjusts the output to control the oil flow in the main oil circuit according to the load. Meanwhile, the accumulator adaptively adjusts according to the system oil pressure to ensure that there are no sudden pressure changes during the entire operation. In semi-active control mode, the piston pump assembly is in a zero-speed control state, applying a reverse torque to the piston to suppress the piston from rotating with the oil, and the solenoid valve in the damper assembly controls the flow of the main oil circuit.

[0014] Thirdly, a vehicle equipped with a piston-pump type hydraulic active suspension system as described in any of the preceding descriptions.

[0015] The beneficial effects of the present invention are as follows: 1. The suspension system of this invention uses a piston pump as a power source. The piston pump has excellent sealing performance, minimal internal leakage, and significantly higher volumetric and overall efficiencies than traditional involute hydraulic gear pumps. Under the same usage scenarios or driving conditions, the volumetric and overall efficiencies of the piston pump-type hydraulic active suspension system are more than 15% higher than those of traditional active suspension systems. This high efficiency means that with the same input power, the piston pump-type hydraulic active suspension system can output greater hydraulic power, providing stronger main drive; or, with the same output power, the piston pump-type hydraulic active suspension system consumes less electrical energy, reducing overall vehicle energy consumption.

[0016] 2. The piston pump-type hydraulic active suspension system has a higher pressure build-up capacity, enabling it to generate a larger pressure differential and thus greater active force. Under the same usage scenarios or driving conditions, the pressure build-up capacity of the piston pump-type hydraulic active suspension system is more than 25% higher than that of traditional active suspension systems. This stronger pressure build-up capacity allows the piston pump-type hydraulic active suspension system to handle more extreme conditions, such as high-speed cornering, emergency braking, and off-road driving, improving vehicle handling stability and safety.

[0017] 3. The piston pump delivers a highly uniform output flow with minimal flow and pressure pulsation. In contrast, traditional involute hydraulic gear pumps, due to their periodic gear meshing, exhibit significant flow and pressure pulsation, which generates noise and vibration, impacting ride comfort. The piston pump-type hydraulic active suspension system has a flow and pressure pulsation of less than 5%, while traditional hydraulic active suspension systems have pulsations exceeding 7%. This reduced pulsation results in smoother operation, lower noise, less vibration, and improved ride comfort.

[0018] 4. Under all operating conditions, the piston pump assembly can continuously adjust its internal swashplate or swing angle according to the load, maintaining optimal operating conditions to ensure low overall energy consumption of the hydraulic active suspension system. The piston pump assembly's controller MCU monitors the pressure and flow rate in the pump control circuit, the motor speed and torque, and control commands sent by the vehicle controller in real time. Based on this information, it calculates the current load and optimal operating point, automatically adjusting the swashplate or swing angle to match the pump's output flow and pressure with the current load, avoiding energy waste. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the piston pump type hydraulic active suspension system in an embodiment of the present invention; Figure 2 This is a schematic diagram of a piston pump type hydraulic active suspension system in an embodiment of the present invention.

[0021] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0022] The components include: 1. Piston pump assembly, 2. Accumulator, 3. Damper assembly, 4. Pump control circuit, and 5. Valve control circuit. Detailed Implementation

[0023] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] Example 1 In a typical embodiment of the present invention, reference is made to Figures 1-2 As shown, a piston pump type hydraulic active suspension system includes a piston pump assembly 1, an accumulator 2, a damper assembly 3, a pump control oil circuit 4, and a valve control oil circuit 5.

[0025] The piston pump assembly 1 serves as the system's power source and is connected to the damper assembly 3 via the pump control oil circuit 4, forming a pump control oil circuit loop. The damper assembly 3 is equipped with a valve control oil circuit 5, which contains a solenoid valve. The damper assembly 3 is connected to the accumulator 2 via the valve control oil circuit 5, forming a valve control oil circuit loop. The pump control oil circuit 4 and the valve control oil circuit 5 are connected in parallel to jointly control the pressure distribution in the upper and lower chambers of the damper assembly 3.

[0026] The piston pump assembly 1 can adopt a three-in-one integrated solution, consisting of a pump head, a piston pump body, and a controller MCU. Each wheel end is equipped with an independent piston pump assembly 1. The piston pump body is equipped with a motor, which is mechanically connected to the piston pump and controlled by the controller MCU.

[0027] The piston pump is a bidirectional variable pump with an internal swashplate or swing angle adjustment mechanism. By adjusting the angle of the swashplate or swing angle, the pump's output flow rate can be infinitely adjusted. The bidirectional variable pump design allows the piston pump to deliver hydraulic oil in both directions. It can pump hydraulic oil from the oil tank to the upper or lower chamber of the damper assembly 3, and it can also draw hydraulic oil back from the damper assembly 3 to the oil tank, thus achieving bidirectional active power control.

[0028] The motor uses a permanent magnet synchronous motor, which can be adapted to 400V, 800V or even higher voltage platforms to meet the electrical system requirements of different vehicle models. The controller MCU integrates a motor drive module, a sensor signal processing module and a communication module, which can monitor parameters such as motor speed, pump output pressure, and flow rate in real time. Based on the control commands sent by the vehicle controller, it can precisely control the motor speed and direction, as well as the angle of the swashplate or swing angle, to achieve precise control of the pump output flow rate and pressure.

[0029] In this embodiment, the pump control oil circuit 4 is a hydraulic pipeline, using a combination of flexible hoses and rigid pipes. The oil ports of the piston pump assembly 1 are connected to the upper and lower chambers of the damper assembly 3 respectively through hydraulic pipelines, forming a closed loop. A pressure sensor is installed on the pump control oil circuit 4 to monitor the hydraulic oil pressure within the pump control oil circuit 4 in real time.

[0030] The hydraulic lines utilize a combination of high-pressure oil-resistant rubber hoses and stainless steel rigid pipes. The hoses connect the piston pump assembly 1 to the vehicle body mounting points, and the vehicle body mounting points to the damper assembly 3, absorbing vibrations and displacements during vehicle operation. The rigid pipes connect the vehicle body mounting points, ensuring the rigidity and pressure resistance of the hydraulic circuit. In an optional example, the hydraulic lines are designed with a working pressure of 250 bar and a burst pressure of 1000 bar, meeting the requirement of a maximum system pressure build-up capacity of over 200 bar, while providing ample safety margin.

[0031] The damper assembly 3 includes the shock absorber body, a compression solenoid valve, and a return solenoid valve. The shock absorber body adopts a dual-chamber structure, with a piston and piston rod inside. The piston divides the hydraulic cylinder into an upper chamber and a lower chamber. One end of the piston rod is fixedly connected to the piston, and the other end is connected to the wheel or axle via a ball joint. The cylinder of the shock absorber body is connected to the vehicle body via a support. The upper and lower chambers are respectively connected to the pump control oil circuit 4 and the valve control oil circuit 5 via oil circuits. The compression solenoid valve and the return solenoid valve are both proportional solenoid directional valves, respectively installed on different valve control oil circuits 5 connecting the upper and lower chambers.

[0032] The compression solenoid valve controls the flow of hydraulic oil during the compression stroke, while the return solenoid valve controls the flow during the return stroke. The proportional solenoid directional valve precisely controls the valve spool opening by adjusting the input current, thereby regulating the flow rate of hydraulic oil through the valve. When the current is zero, the valve is closed; as the current increases, the valve gradually opens, and the flow rate gradually increases; when the current reaches its maximum value, the valve is fully open, and the flow rate reaches its maximum. By precisely controlling the opening of the compression and return solenoid valves, continuous adjustable control of the damping force of the damper assembly can be achieved.

[0033] Accumulator 2 is a pneumatic accumulator, which is connected to the upper and lower chambers of damper assembly 3 through valve-controlled oil circuit 5. The accumulator 2 is internally divided into a gas chamber and an oil chamber. The gas chamber is filled with high-pressure nitrogen, and the oil chamber is connected to valve-controlled oil circuit 5.

[0034] The air chamber and oil chamber are isolated by an elastic air bladder. When the hydraulic oil pressure in the valve-controlled oil circuit 5 increases, the hydraulic oil enters the oil chamber of the accumulator 2, compressing the air bladder. The nitrogen in the air chamber is compressed, the pressure increases, and the accumulator 2 stores hydraulic energy. When the hydraulic oil pressure in the valve-controlled oil circuit 5 decreases, the high-pressure nitrogen in the air chamber pushes the air bladder, forcing the hydraulic oil in the oil chamber out and replenishing it to the valve-controlled oil circuit 5, releasing the stored hydraulic energy.

[0035] The main function of accumulator 2 is to replenish hydraulic oil in a timely manner, alleviate flow and pressure pulsations, and reduce sudden changes in system pressure. During rapid pressure build-up or depressurization of the system, accumulator 2 can absorb or release hydraulic oil, avoiding drastic pressure fluctuations in the oil circuit and ensuring stable system operation. The charging pressure of accumulator 2 is set according to the system's working pressure range, generally set to 80% to 90% of the system's minimum working pressure, to ensure that accumulator 2 can work effectively throughout the entire working pressure range.

[0036] Understandably, the structure of accumulator 2 is based on existing technology.

[0037] In this embodiment, the pump-controlled oil circuit 4 and the valve-controlled oil circuit 5 are connected in parallel to jointly determine the pressure distribution in the upper and lower chambers of the damper assembly 3. The pump-controlled oil circuit 4 is the main oil circuit, directly connecting the piston pump assembly 1 and the upper and lower chambers of the damper assembly 3, and serves as the main flow channel for hydraulic oil. The valve-controlled oil circuit 5 is connected in parallel to the pump-controlled oil circuit 4, controlling the flow of hydraulic oil between the upper and lower chambers, as well as the flow between the hydraulic oil and the accumulator 2, through a compression solenoid valve and a reset solenoid valve.

[0038] In pump control mode, the piston pump assembly 1 actively pumps hydraulic oil, and changes the pressure difference between the upper and lower chambers of the damper assembly 3 through the pump control oil circuit 4 to generate active force. At this time, the solenoid valve on the valve control oil circuit 5 is in a fully open or partially open state, playing an auxiliary adjustment role.

[0039] In valve-controlled mode, piston pump assembly 1 is in zero-speed control or energy recovery state and does not actively pump hydraulic oil. The damping force of damper assembly 3 is mainly achieved by adjusting the opening of the solenoid valve on valve control oil circuit 5. At this time, pump control oil circuit 4 acts as a passive flow channel.

[0040] The working principle of the piston pump type hydraulic active suspension system is as follows: In valve-controlled mode, piston pump assembly 1 is in auxiliary control mode, while the solenoid valve in damper assembly 3 performs primary control. When the wheel reciprocates up and down due to road surface excitation, the piston in damper assembly 3 reciprocates within the hydraulic cylinder, driving hydraulic oil to flow between the upper and lower chambers. The vehicle controller sends control current to the compression and return solenoid valves of damper assembly 3 based on the vehicle's driving status and road conditions. By adjusting the current, the opening degree of the solenoid valves is precisely controlled, thereby regulating the flow rate of hydraulic oil through valve-controlled oil circuit 5 between the upper and lower chambers.

[0041] When it is necessary to increase the damping force, reduce the opening of the solenoid valve to restrict the flow of hydraulic oil and increase the pressure difference between the upper and lower chambers; when it is necessary to reduce the damping force, increase the opening of the solenoid valve to increase the flow of hydraulic oil and decrease the pressure difference between the upper and lower chambers.

[0042] In valve-controlled mode, the piston pump assembly 1 can automatically adjust the output according to the load. When the pressure in the pump control oil circuit 4 is detected to be too high or too low, the swashplate or swing angle is automatically adjusted to increase or decrease the pump's output flow and maintain the stability of the system pressure.

[0043] Understandably, in pump-controlled mode, piston pump assembly 1 performs primary control, while the solenoid valve in damper assembly 3 operates in auxiliary control mode. The vehicle controller sends control commands to the MCU (Microcontroller Unit) of piston pump assembly 1 based on the vehicle's driving conditions and suspension control requirements. The MCU controls the motor's speed and direction, as well as the swashplate or swing angle, precisely controlling the pump's output flow and direction.

[0044] When the main force in the compression direction is needed, the piston pump assembly 1 pumps hydraulic oil to the upper chamber of the damper assembly 3, increasing the pressure in the upper chamber and pushing the piston downward to generate the main force in compression; when the main force in the recovery direction is needed, the piston pump assembly 1 pumps hydraulic oil to the lower chamber of the damper assembly 3, increasing the pressure in the lower chamber and pushing the piston upward to generate the main force in recovery.

[0045] By precisely controlling the pump's output flow rate, the pressure difference between the upper and lower chambers of the damper assembly 3 can be precisely controlled, thereby precisely controlling the magnitude of the driving force. The piston pump assembly 1 can not only control the output flow rate by adjusting the motor speed, but also automatically adjust the internal swashplate or swing angle according to the load, achieving stepless adjustment of the output flow rate. When the load is small, decreasing the swashplate or swing angle reduces the pump's output flow rate and lowers energy consumption; when the load is large, increasing the swashplate or swing angle increases the pump's output flow rate and improves output power. This variable adjustment capability allows the piston pump assembly 1 to always operate at its optimal efficiency point, reducing system energy consumption.

[0046] The piston pump type hydraulic active suspension system in this embodiment has two working modes: active control mode and semi-active control mode.

[0047] In active control mode, when the vehicle sensors detect significant changes in lateral, side, or vertical acceleration, such as when the vehicle is driving on a Class D or Class E road, making a sharp turn, or undergoing emergency braking or rapid acceleration, the system determines that active intervention in the suspension is needed to improve the vehicle's handling stability and ride comfort. At this time, the piston pump type hydraulic active suspension system enters active control mode.

[0048] In active control mode, the piston pump assembly 1 actively performs external work. According to the control commands sent by the vehicle controller, it precisely controls the speed and direction of the motor, as well as the angle of the swashplate or swing angle, and actively pumps hydraulic oil to the upper or lower chamber of the damper assembly 3 to change the pressure distribution in the upper and lower chambers and generate active force.

[0049] Throughout operation, the piston pump assembly 1 adaptively adjusts its output according to the load conditions and monitors the pressure in the pump control oil circuit 4 in real time. When the pressure deviates from the target value, it automatically adjusts the swashplate or swing angle to adjust the output flow rate, allowing the pressure to quickly return to the target value. The accumulator 2 adaptively adjusts according to the system oil pressure. When the system pressure rises, it absorbs excess hydraulic oil to prevent pressure overshoot; when the system pressure drops, it releases the stored hydraulic oil to prevent insufficient pressure.

[0050] Through the active control of the piston pump assembly 1 and the adaptive adjustment of the accumulator 2, it is ensured that there will be no sudden pressure changes during the entire operation, ultimately achieving precise control of the active force. In active control mode, the system's maximum pressure build-up capacity can reach over 200 bar, the maximum flow rate can reach over 45 L / min, the time to switch from the positive maximum flow rate to the negative maximum flow rate is less than 100 ms, the maximum positive and negative pressure build-up switching time is less than 100 ms, the system response time is shortened by more than 50% compared to existing active suspensions, and the pressure build-up capacity is improved by more than 25% compared to existing systems.

[0051] In semi-active control mode, when the vehicle sensors detect no significant changes in the vehicle's lateral, longitudinal, or vertical acceleration, such as when the vehicle is traveling at a constant speed on a flat road, the system determines that active intervention in the suspension is unnecessary. At this time, the piston-pump hydraulic active suspension system enters semi-active control mode to reduce energy consumption. The semi-active control mode has three operating states depending on the road surface level.

[0052] When the vehicle is traveling on Class A or Class B roads, corresponding to relatively smooth surfaces such as highways and provincial roads, the piston pump assembly 1 is in a zero-speed control state. In this state, the controller MCU applies a reverse torque to the motor, inhibiting the piston from rotating with the hydraulic oil, keeping the piston pump stationary or rotating at low speed, and preventing it from actively pumping hydraulic oil. At this time, the damping force of the damper assembly 3 is mainly controlled by the solenoid valve on the valve control circuit 5.

[0053] The vehicle controller sends control current to the compression solenoid valve and the reset solenoid valve according to the vehicle's driving status, adjusts the opening of the solenoid valve, controls the flow of hydraulic oil between the upper and lower chambers, and adjusts the magnitude of the damping force.

[0054] The piston pump assembly 1 can also automatically adjust the applied reverse torque according to the load. When a large pressure fluctuation is detected in the pump control oil circuit 4, the reverse torque is appropriately increased to enhance the braking effect on the piston pump and reduce the pressure fluctuation. When a small pressure fluctuation is detected in the pump control oil circuit 4, the reverse torque is appropriately reduced to reduce energy consumption.

[0055] In zero-speed control mode, the piston pump assembly 1 is always in a low-energy-consumption state, and its energy consumption can be reduced by more than 15% compared with traditional involute hydraulic gear pumps.

[0056] When the vehicle is traveling on Class C roads, corresponding to suburban roads, rural roads, etc., the piston pump assembly 1 enters the adaptive energy recovery mode. In the adaptive energy recovery mode, the piston pump assembly 1 adaptively selects between two operating states: energy recovery or zero-speed control, based on the characteristics of the road surface.

[0057] If the road surface features are pronounced, such as continuous undulations, the reciprocating motion of the wheels is large. The piston of damper assembly 3 reciprocates frequently within the hydraulic cylinder, driving a large flow of hydraulic oil between the upper and lower chambers. At this time, piston pump assembly 1 no longer performs external work and does not apply reverse torque to the motor, allowing the piston of the piston pump to rotate freely with the hydraulic oil. The hydraulic oil drives the piston of the piston pump to rotate, driving the motor to rotate. The motor acts as a generator, converting mechanical energy into electrical energy. The generated electrical energy is fed back to the vehicle's power battery for storage through the energy feedback module of the controller MCU, achieving energy recovery and reducing overall vehicle energy consumption.

[0058] If the road surface features are small, such as locally damaged road surfaces, the reciprocating motion amplitude of the wheels is small, the piston of the damper assembly 3 does not reciprocate frequently in the hydraulic cylinder, and the hydraulic oil flow is small. At this time, the piston pump assembly 1 is in a zero-speed control state, applying a reverse torque to the motor to suppress the piston of the piston pump from rotating with the hydraulic oil. The damping force of the damper assembly 3 is mainly controlled by the solenoid valve on the valve control oil circuit 5.

[0059] The piston pump assembly 1 can also automatically adjust the applied reverse torque according to the load. Throughout the process, the piston pump assembly 1 can always be in a low energy consumption state. Compared with the traditional involute hydraulic gear pump, the energy consumption can be reduced by more than 15%.

[0060] Understandably, under all operating conditions, the piston pump assembly 1 can always be continuously adjusted according to the load by adjusting the internal swashplate or swing angle, and always be in the best working state to ensure that the overall energy consumption of the hydraulic active suspension system is kept low.

[0061] The controller MCU of the piston pump assembly 1 monitors the pressure and flow rate in the pump control oil circuit 4, the speed and torque of the motor, and the control commands sent by the vehicle controller in real time. Based on this information, it calculates the current load and the optimal operating point in real time, and automatically adjusts the swashplate or swing angle to match the pump's output flow rate and pressure with the current load, thus avoiding energy waste.

[0062] The piston pump-type hydraulic active suspension system can also be combined with a pre-aiming control system to adapt to more usage scenarios and operating conditions. The pre-aiming control system uses sensors such as onboard cameras or lidar to detect road undulations in advance and transmits this information to the vehicle controller. Based on this information, the vehicle controller calculates the optimal suspension control strategy in advance and sends control commands to the piston pump assembly 1 and damper assembly 3. This allows the suspension to adjust damping or active forces before the wheels reach the road undulations, counteracting the impact of road undulations on the vehicle body and further improving ride comfort and handling stability. Compared to traditional hydraulic active suspension systems with pre-aiming control systems, the piston pump-type hydraulic active suspension system combined with the pre-aiming control system can cover over 95% of usage scenarios and operating conditions, offering greater adaptability.

[0063] The piston pump-type hydraulic active suspension system in this embodiment uses a piston pump as its power source. The piston pump boasts excellent sealing performance, minimal internal leakage, and significantly higher volumetric and overall efficiencies than traditional involute hydraulic gear pumps. Under the same usage scenarios or driving conditions, the volumetric and overall efficiencies of the piston pump-type hydraulic active suspension system are more than 15% higher than those of traditional active suspension systems. This high efficiency means that with the same input power, the piston pump-type hydraulic active suspension system can output greater hydraulic power, providing stronger main drive; or, with the same output power, it consumes less electrical energy, reducing overall vehicle energy consumption.

[0064] The piston-pump hydraulic active suspension system can build up pressure to over 200 bar, while traditional hydraulic active suspension systems can only reach 150 bar. This higher pressure build-up capacity means the system can generate a larger pressure differential, resulting in greater active force. Under the same usage scenarios or driving conditions, the piston-pump hydraulic active suspension system's pressure build-up capacity is more than 25% higher than that of traditional active suspension systems. This stronger pressure build-up capacity allows the piston-pump hydraulic active suspension system to handle more extreme conditions, such as high-speed cornering, emergency braking, and off-road driving, improving vehicle handling stability and safety.

[0065] The piston pump-type hydraulic active suspension system can achieve a maximum flow rate of over 45 L / min, while the maximum flow rate of a traditional hydraulic active suspension system is 30 L / min. A larger flow rate means the system can change the pressure distribution in the upper and lower chambers of the damper more quickly, thus generating active force or adjusting damping force more rapidly. The piston pump-type hydraulic active suspension system switches from maximum flow rate to maximum flow rate in less than 100 ms, and the maximum positive / negative pressure build-up switching time is also less than 100 ms, while traditional hydraulic active suspension systems require more than 150 ms. Under the same usage scenarios or driving conditions, the response time of the piston pump-type hydraulic active suspension system is more than 50% shorter than that of traditional active suspensions. This faster response speed allows the piston pump-type hydraulic active suspension system to respond more promptly to road surface excitations and vehicle dynamic changes, improving the control accuracy and effectiveness of the suspension.

[0066] Piston pumps are variable displacement pumps, automatically adjusting their output flow rate according to the load for precise control. Traditional involute hydraulic gear pumps are typically fixed displacement pumps, with output flow rate proportional to speed, unable to adjust according to load, resulting in poor control precision and high energy consumption and overheating under low loads. Piston pump-type hydraulic active suspension systems, by adjusting the swashplate or tilt angle, can regulate the output flow rate while maintaining a constant speed, matching the output flow rate to the load, avoiding energy waste, and reducing system energy consumption. Under the same usage scenarios or driving conditions, the overall energy consumption of piston pump-type hydraulic active suspension systems is more than 15% lower than that of traditional active suspension systems.

[0067] The piston pump delivers a highly uniform output flow with minimal flow and pressure pulsation. In contrast, traditional involute hydraulic gear pumps, due to their periodic gear meshing, exhibit significant flow and pressure pulsation, which generates noise and vibration, impacting ride comfort. The piston pump-type hydraulic active suspension system boasts flow and pressure pulsation of less than 5%, while traditional hydraulic active suspension systems experience pulsation exceeding 7%. This reduced pulsation results in smoother operation, lower noise, less vibration, and improved ride comfort for the piston pump-type hydraulic active suspension system.

[0068] Piston pumps have high power density, resulting in smaller size and weight for the same output power. Under the same requirements and conditions, a piston pump-type hydraulic active suspension system is more than 3 kg lighter than a traditional hydraulic active suspension system. The lighter weight helps reduce overall vehicle mass, improving fuel economy or driving range. The smaller size facilitates better vehicle layout and reduces the space occupied within the vehicle interior.

[0069] Piston pump-type hydraulic active suspension systems can achieve energy recovery, while traditional hydraulic active suspension systems cannot. During vehicle operation, the suspension absorbs vibration energy from the road surface. Traditional hydraulic active suspension systems dissipate this vibration energy as heat through dampers, resulting in energy waste. In its semi-active control mode, the piston pump-type hydraulic active suspension system can convert vibration energy into electrical energy and feed it back to the battery, achieving energy recovery and further reducing overall vehicle energy consumption.

[0070] Understandably, the piston pump assembly adopts a three-in-one design, consisting of a pump head, a piston pump body, and a controller.

[0071] Example 2 The difference between this embodiment and Embodiment 1 is that the piston pump assembly 1 adopts a five-in-one integrated solution. The other structures are the same as in Embodiment 1 and will not be described again.

[0072] The piston pump assembly 1 adopts a five-in-one integrated design, consisting of two pump heads, two piston pump bodies, and a controller MCU. The left and right wheels share one piston pump assembly 1. The two piston pump bodies correspond to the left and right wheels respectively. Each piston pump body contains a motor, which is mechanically connected to the piston pump. Both motors are controlled by the same controller MCU. The controller MCU can independently control the motor speed, steering, and swashplate or swing angle of the two piston pump bodies, achieving independent control of the left and right wheel suspensions.

[0073] The five-in-one solution offers higher integration, reducing system cost and weight. A single controller (MCU) can simultaneously monitor and control two piston pump bodies, achieving coordinated control of the left and right wheel suspensions. For example, when the vehicle is turning, the MCU can increase the main force of the outer wheel suspension and decrease the main force of the inner wheel suspension based on the turning direction, suppressing body roll and improving handling stability. When the vehicle is braking, the MCU can increase the main force of the front wheel suspension and decrease the main force of the rear wheel suspension, suppressing body roll and improving braking stability. When the vehicle is accelerating, the MCU can increase the main force of the rear wheel suspension and decrease the main force of the front wheel suspension, suppressing body pitch and improving acceleration performance.

[0074] The five-in-one solution works similarly to the three-in-one solution, except that the controller MCU needs to control two piston pump bodies simultaneously. In valve-controlled mode, both piston pump bodies are in auxiliary control mode, automatically adjusting their output according to the load of their respective wheels. In pump-controlled mode, the controller MCU independently controls the motor speed, steering, and swashplate or swing angle of the two piston pump bodies according to the control commands sent by the vehicle controller, achieving independent active force control of the left and right wheel suspensions.

[0075] In active control mode, both piston pumps actively perform work, generating corresponding active force according to the control requirements of their respective wheels. In semi-active control mode, both piston pumps are in a zero-speed control state or an energy recovery state, reducing energy consumption or recovering energy.

[0076] The five-in-one solution achieves essentially the same technical results as the three-in-one solution, outperforming the traditional involute hydraulic gear pump-type active suspension system in terms of volumetric efficiency, overall efficiency, pressure build-up capacity, flow rate, response speed, pulsation, weight, energy consumption, and energy recovery. Furthermore, the five-in-one solution uses a single MCU to simultaneously control the left and right wheel suspensions, achieving coordinated control of both sides and further improving vehicle handling stability and ride comfort.

[0077] Example 3 like Figures 1-2 As shown, this embodiment provides a method for operating a piston pump type hydraulic active suspension system, employing the piston pump type hydraulic active suspension system described in Embodiment 1 or Embodiment 2, including the following steps: Step S1: System Initialization. After the vehicle starts, the piston pump type hydraulic active suspension system performs a self-check, verifying the normal operation of the piston pump assembly 1, damper assembly 3, accumulator 2, pump control circuit 4, valve control circuit 5, and all sensors and controllers. If a fault is detected, the system issues a fault alarm and enters fail-safe mode, limiting the active suspension function while ensuring basic passive suspension function. If the self-check is normal, the system enters normal operating mode.

[0078] Step S2: Acquire sensor signals. The vehicle controller acquires various sensor signals from the vehicle in real time, including vehicle speed sensor, acceleration sensor, steering angle sensor, brake pressure sensor, throttle opening sensor, suspension displacement sensor, vehicle height sensor, wheel speed sensor, etc. The MCU controller of piston pump assembly 1 acquires pressure sensor signals, flow sensor signals, motor speed sensor signals, motor torque sensor signals, etc., in the pump control circuit 4 in real time. The controller of damper assembly 3 acquires pressure sensor signals, solenoid valve position sensor signals, etc., in the valve control circuit 5 in real time.

[0079] Step S3: Determine the operating mode. Based on the collected sensor signals, the vehicle controller determines the vehicle's driving status and road conditions, and then determines the operating mode of the piston pump-type hydraulic active suspension system. The determination logic is as follows: If the lateral acceleration, side acceleration, or vertical acceleration of the vehicle is detected to exceed the set threshold, such as lateral acceleration greater than 0.3g, side acceleration greater than 0.3g, or vertical acceleration greater than 0.5g, the vehicle is determined to be in a dynamic condition, such as sharp turn, emergency braking, rapid acceleration, or bumpy road surface, and the system enters active control mode and executes step S4.

[0080] If the vehicle's lateral acceleration, side acceleration, and vertical acceleration are all detected to be less than the set thresholds, the system determines that the vehicle is in a stable operating condition and enters a semi-active control mode. The specific operating state of the semi-active control mode is further determined based on the road surface level. If the road surface level is detected as Class A or B, i.e., flat roads such as highways or provincial roads, the system enters a zero-speed control state and executes step S5. If the road surface level is detected as Class C, i.e., suburban roads or rural roads, the system enters an adaptive energy recovery mode and executes step S6.

[0081] Understandably, road surface grade can be determined by a combination of signals from suspension displacement sensors, vehicle acceleration sensors, and wheel speed sensors, or by obtaining current road surface grade information through in-vehicle navigation systems or vehicle-to-everything (V2X) systems.

[0082] Step S4: Active Control Mode. In active control mode, the vehicle controller calculates the required active force for each wheel suspension based on the vehicle's driving status and suspension control requirements, and sends control commands, including target pressure and target flow rate, to the MCU controller of piston pump assembly 1. Upon receiving the control commands, the MCU controller controls the motor's speed and direction, as well as the swashplate or tilt angle, causing piston pump assembly 1 to output the corresponding flow rate and pressure. The specific control strategy is as follows: If compression is required, the MCU controller rotates the motor forward, driving the piston pump to pump hydraulic oil to the upper chamber of damper assembly 3, increasing the pressure in the upper chamber. Simultaneously, the MCU controller adjusts the swashplate or swing angle based on the difference between the target pressure and the current pressure, controlling the output flow rate to quickly reach the target pressure in the upper chamber. Once the target pressure is reached, the MCU controller maintains the swashplate or swing angle to maintain the output flow rate, stabilizing the upper chamber pressure at the target pressure.

[0083] If the main driving force for the return direction is required, the MCU controller reverses the motor, driving the piston pump to pump hydraulic oil to the lower chamber of damper assembly 3, increasing the pressure in the lower chamber. Simultaneously, the MCU controller adjusts the swashplate or swing angle based on the difference between the target pressure and the current pressure, controlling the output flow rate to quickly bring the lower chamber pressure to the target pressure. Once the lower chamber pressure reaches the target pressure, the MCU controller maintains the swashplate or swing angle to maintain the output flow rate, stabilizing the lower chamber pressure at the target pressure.

[0084] During active control, the piston pump assembly 1 adaptively adjusts its output according to the load. The controller MCU monitors the pressure in the pump control oil circuit 4 in real time. When the pressure deviates from the target value, it automatically adjusts the swashplate or swing angle to adjust the output flow rate, allowing the pressure to quickly return to the target value. The accumulator 2 adaptively adjusts according to the system oil pressure. When the system pressure rises, it absorbs excess hydraulic oil to avoid pressure overshoot; when the system pressure drops, it releases the stored hydraulic oil to avoid insufficient pressure, ensuring that there are no sudden pressure changes throughout the entire operation.

[0085] In active control mode, the solenoid valve of damper assembly 3 is in auxiliary control mode. The vehicle controller can send control current to the compression solenoid valve and the reset solenoid valve as needed to fine-tune the opening of the solenoid valve, assist in adjusting the pressure distribution in the upper and lower chambers of the damper, and optimize the control effect of the active force.

[0086] In active control mode, the system's maximum pressure build-up capacity can reach over 200 bar, and the maximum flow rate can reach over 45 L / min. When switching from the main power in the compression direction to the main power in the recovery direction, the controller MCU first controls the motor to decelerate to zero, then controls the motor to accelerate in the opposite direction, while simultaneously adjusting the swashplate or swing angle to switch the output flow rate from the positive maximum flow rate to the negative maximum flow rate. The entire switching process takes less than 100 ms. When switching from the positive maximum pressure build-up to the negative maximum pressure build-up, the controller MCU first controls the piston pump to decrease the upper chamber pressure, then controls the piston pump to increase the lower chamber pressure, with the entire switching process taking less than 100 ms. This rapid switching capability allows the system to respond promptly to rapid changes in vehicle dynamics, improving the suspension's control performance.

[0087] Step S5: Zero-speed control state. In the zero-speed control state, the piston pump assembly 1 does not actively pump hydraulic oil, and the damping force of the damper assembly 3 is mainly controlled by the solenoid valve on the valve control circuit 5. The specific control strategy is as follows: The controller MCU applies reverse torque to the motor to suppress the piston of the piston pump from rotating with the hydraulic oil, keeping the piston pump stationary or rotating at low speed. The magnitude of the reverse torque is automatically adjusted according to the current load. The controller MCU monitors the pressure in the pump control oil circuit 4 in real time. When the pressure fluctuation is large, the reverse torque is increased to enhance the braking effect on the piston pump and reduce pressure fluctuation; when the pressure fluctuation is small, the reverse torque is decreased to reduce energy consumption.

[0088] The vehicle controller sends control current to the compression and return solenoid valves of the damper assembly 3 based on the vehicle's driving status, adjusting the valve openings to control the flow of hydraulic oil between the upper and lower chambers and thus adjusting the damping force. When the wheel moves upward due to road surface excitation, the damper is in its compression stroke, the upper chamber volume decreases, and hydraulic oil flows from the upper chamber to the lower chamber through the compression solenoid valve. The vehicle controller adjusts the opening of the compression solenoid valve according to the required damping force, controlling the hydraulic oil flow. When a greater damping force is needed, the opening of the compression solenoid valve is decreased to restrict hydraulic oil flow; when a less damping force is needed, the opening of the compression solenoid valve is increased to increase hydraulic oil flow. When the wheel moves downward due to road surface excitation, the damper is in its return stroke, the lower chamber volume decreases, and hydraulic oil flows from the lower chamber to the upper chamber through the return solenoid valve. The vehicle controller adjusts the opening of the return solenoid valve according to the required damping force, controlling the hydraulic oil flow.

[0089] In zero-speed control mode, the piston pump assembly 1 is always in a low-energy-consumption state, consuming only a small amount of electrical energy to maintain the reverse torque of the motor. Compared with traditional involute hydraulic gear pumps that require continuous rotation to consume electrical energy, the energy consumption of the piston pump type hydraulic active suspension system can be reduced by more than 15%.

[0090] Step S6: Adaptive Energy Recovery Mode. In adaptive energy recovery mode, the piston pump assembly 1 adaptively selects either energy recovery or zero-speed control based on the road surface characteristics. The specific control strategy is as follows: The controller MCU monitors suspension displacement sensor signals and vehicle acceleration sensor signals in real time to determine the magnitude of road surface features. The judgment criteria can be the amplitude and frequency of suspension displacement, or the amplitude and frequency of vehicle acceleration, etc.

[0091] If the road surface features are clearly defined, such as suspension displacement exceeding a set threshold or vehicle acceleration exceeding a set threshold, the MCU (Microcontroller Unit) determines that the reciprocating motion of the wheels is significant, resulting in a large hydraulic fluid flow, and the system enters energy recovery mode. In energy recovery mode, the MCU does not apply reverse torque to the motor, allowing the piston pump piston to rotate freely with the hydraulic fluid. When the damper is in its compression stroke, hydraulic fluid flows from the upper chamber to the lower chamber, pushing the piston pump piston to rotate, thus driving the motor. When the damper is in its recovery stroke, hydraulic fluid flows from the lower chamber to the upper chamber, pushing the piston pump piston to rotate in the opposite direction, thus driving the motor to rotate in the opposite direction. The motor operates as a generator, converting mechanical energy into electrical energy. The MCU's energy feedback module rectifies and stabilizes the generated electrical energy before feeding it back into the vehicle's battery for storage. The efficiency of energy recovery depends on the efficiency of the piston pump and motor, as well as the efficiency of the energy feedback module. The high efficiency of the piston pump ensures high energy recovery efficiency, effectively reducing overall vehicle energy consumption.

[0092] If the road surface features are determined to be small, such as the suspension displacement amplitude being less than the set threshold and the vehicle acceleration amplitude being less than the set threshold, the controller MCU determines that the reciprocating motion amplitude of the wheels is small and the hydraulic oil flow is small, the system enters the zero-speed control state, and executes the control strategy of step S5.

[0093] Step S7: Pre-aiming control. If the vehicle is equipped with a pre-aiming control system, the piston pump type hydraulic active suspension system can work in conjunction with the pre-aiming control system to further improve the control effect of the suspension.

[0094] The anti-sight control system uses sensors such as onboard cameras or lidar to detect road surface undulations in advance and transmits this information to the vehicle controller. Based on the road information and vehicle speed, the vehicle controller calculates the time it takes for the wheels to reach the road surface undulations and the impact of these undulations on the vehicle body. The vehicle controller then calculates the optimal suspension control strategy in advance and sends control commands to the piston pump assembly 1 and damper assembly 3, allowing the suspension to adjust damping force or drive force before the wheels reach the road surface undulations.

[0095] For example, if a bump is detected on the road ahead, the vehicle controller calculates the time it will take for the wheel to reach the bump and sends a control command to the piston pump assembly 1 in advance. This causes the piston pump assembly 1 to increase the pressure in the lower chamber of the damper before the wheel reaches the bump, generating an upward force to counteract the upward impact of the bump on the vehicle body and reduce the vertical vibration of the vehicle body. Similarly, if a pothole is detected on the road ahead, the vehicle controller sends a control command to the piston pump assembly 1 in advance, causing the piston pump assembly 1 to increase the pressure in the upper chamber of the damper before the wheel reaches the pothole, generating a downward force to counteract the downward impact of the pothole on the vehicle body and reduce the vertical vibration of the vehicle body.

[0096] Through anti-aiming control, the piston-pump hydraulic active suspension system can more proactively respond to road surface disturbances, further improving ride comfort and handling stability. The piston-pump hydraulic active suspension system, combined with the anti-aiming control system, can cover over 95% of usage scenarios and operating conditions.

[0097] Step S8: System Monitoring and Fault Handling. During system operation, the controller continuously monitors the signals from various sensors and the operating status of actuators to determine whether the system is functioning correctly. If an abnormal sensor signal is detected, such as a pressure sensor signal exceeding the normal range, or if an actuator malfunctions, such as a motor stall or a solenoid valve jamming, the controller determines that a system fault has occurred, issues a fault alarm, and enters a fail-safe mode.

[0098] In fail-safe mode, the system restricts the active functions of the suspension, switches the solenoid valve to the fail-safe position, and ensures basic passive suspension functions so that the vehicle can be safely driven to a repair shop.

[0099] The working method of this embodiment fully leverages the technical advantages of the piston pump type hydraulic active suspension system. Through the coordinated operation of valve control and pump control, as well as the flexible switching between active control mode and semi-active control mode, it achieves precise control of suspension damping force and active force, improving vehicle ride comfort, handling stability and safety, while reducing system energy consumption and realizing energy recovery, which is in line with the development trend of energy conservation and environmental protection.

[0100] Example 4 like Figures 1-2 As shown, this embodiment provides a vehicle equipped with the piston pump type hydraulic active suspension system described in Embodiment 1 or Embodiment 2.

[0101] The vehicle is a new energy vehicle, comprising a body, chassis, powertrain, battery system, and vehicle control system. The powertrain includes a drive motor, reducer, and differential. The battery system provides power to the powertrain and the piston-pump hydraulic active suspension system. The vehicle control system includes a vehicle controller, battery management system, motor controller, and piston-pump hydraulic active suspension system controller. These controllers communicate via an onboard CAN bus or Ethernet to achieve coordinated control of the entire vehicle.

[0102] The piston pump-type hydraulic active suspension system is mounted on the vehicle chassis. In the three-in-one configuration, each wheel is equipped with one piston pump assembly 1, one damper assembly 3, and one accumulator 2, for a total of four piston pump assemblies 1, four damper assemblies 3, and four accumulators 2 for the four wheels. The piston pump assembly 1 is located on the vehicle body near the wheel and is fixed to the longitudinal or transverse beams of the body via brackets. The cylinder of the damper assembly 3 is fixed to the vehicle body via supports, and the piston rod is connected to the wheel or axle via ball joints. The accumulator 2 is located near the damper assembly 3 and is fixed to the vehicle body via brackets. The piston pump assembly 1 and the damper assembly 3 are connected via a pump control oil circuit 4, using a combination of hoses and rigid pipes. The hoses absorb vibrations and displacements during vehicle operation, while the rigid pipes ensure the rigidity and pressure resistance of the oil circuit.

[0103] In the five-in-one configuration, the left and right wheels share a single piston pump assembly 1, with one piston pump assembly 1 for the front wheels and one for the rear wheels, for a total of two piston pump assemblies 1. The piston pump assemblies 1 are located in the center of the vehicle body and are fixed to the longitudinal or transverse beams via brackets. The two pump heads of each piston pump assembly 1 are connected to the damper assemblies 3 of the left and right wheels respectively via pump control oil circuits 4. Other arrangements are similar to the three-in-one configuration.

[0104] The vehicle is also equipped with a pre-aiming control system, including sensors such as onboard cameras or lidar, mounted at the front of the vehicle to detect road surface undulations. The pre-aiming control system communicates with the vehicle controller, transmitting road information to it. Based on this information, the vehicle controller calculates the optimal suspension control strategy in advance and sends control commands to the piston-pump hydraulic active suspension system to achieve pre-aiming control.

[0105] The vehicle's overall control system collects various sensor signals from the vehicle, including vehicle speed sensor, acceleration sensor, steering angle sensor, brake pressure sensor, throttle opening sensor, suspension displacement sensor, vehicle height sensor, and wheel speed sensor. Based on these signals, it determines the vehicle's driving state and road conditions, calculates the suspension control requirements, and sends control commands to the piston pump-type hydraulic active suspension system. The piston pump-type hydraulic active suspension system adjusts the damping force or active force of each wheel suspension according to the control commands, thereby controlling the vehicle's attitude.

[0106] The vehicle's battery system provides electrical energy to the piston pump-type hydraulic active suspension system. The motor of the piston pump assembly 1 draws electrical energy from the battery system to drive the piston pump. In energy recovery mode, the motor of the piston pump assembly 1 operates as a generator, converting vibration energy into electrical energy. This energy is then fed back to the battery system for storage via the energy feedback module of the controller MCU, achieving energy recovery and reducing overall vehicle energy consumption. The battery management system monitors parameters such as voltage, current, and temperature of the battery system to ensure its safe operation.

[0107] After the vehicle in this embodiment is equipped with a piston pump type hydraulic active suspension system, the overall vehicle performance is significantly improved, as shown in the following details: The piston-pump hydraulic active suspension system effectively isolates the impact of road surface excitations on the vehicle body by precisely controlling the damping force and active force of the suspension, reducing vertical, pitch, and roll vibrations and improving ride comfort. Under the same road conditions, vehicles equipped with the piston-pump hydraulic active suspension system have a root mean square acceleration value that is more than 30% lower than those equipped with traditional passive suspension, improving the subjective comfort rating of occupants by one level.

[0108] The piston pump-type hydraulic active suspension system actively controls the damping force and active force of the suspension to suppress body roll, pitch, and yaw movements, thereby improving vehicle handling stability. During sharp turns, the system increases the active force on the outer suspension wheels and decreases the active force on the inner suspension wheels, suppressing body roll, reducing the roll angle, and increasing cornering limits. During emergency braking, the system increases the active force on the front suspension wheels and decreases the active force on the rear suspension wheels, suppressing body roll, reducing the roll angle, maintaining vehicle stability, and shortening braking distance.

[0109] Under rapid acceleration, the system increases the main force of the rear suspension and decreases the main force of the front suspension, suppressing body roll, reducing the roll angle, and improving acceleration performance. Vehicles equipped with the piston pump type hydraulic active suspension system achieve a passing speed of more than 10% higher in the moose test compared to vehicles equipped with traditional passive suspension, and a lateral acceleration of more than 15% higher in the double lane change test compared to vehicles equipped with traditional passive suspension.

[0110] The piston pump-type hydraulic active suspension system improves handling stability, reduces the risk of vehicle loss of control, and enhances active safety. The system's rapid response and powerful active force output enable it to handle various emergency situations promptly, such as emergency obstacle avoidance and driving on slippery surfaces, thus improving vehicle safety.

[0111] In addition, the system's fail-safe design ensures that even if the system malfunctions, the vehicle can still maintain basic passive suspension functions and safely drive to a repair shop, avoiding safety accidents caused by suspension system failure.

[0112] The vehicle's off-road capability is significantly improved. The piston-pump hydraulic active suspension system can actively adjust the vehicle height according to road conditions, improving its off-road capability. When driving on off-road terrain or over obstacles, the system can increase the vehicle height and ground clearance to prevent the chassis from colliding with the road surface or obstacles. At high speeds, the system can lower the vehicle height to reduce wind resistance and improve fuel economy or driving range.

[0113] The high efficiency, variable displacement capability, and energy recovery function of the piston pump type hydraulic active suspension system reduce the overall energy consumption of the system by more than 15% compared with traditional hydraulic active suspension systems.

[0114] In semi-active control mode, the system is in a low-energy consumption state or energy recovery state, further reducing the vehicle's energy consumption. Under the same driving conditions, vehicles equipped with piston pump type hydraulic active suspension systems have more than 5% lower overall energy consumption and more than 5% higher driving range compared to vehicles equipped with traditional hydraulic active suspension systems.

[0115] The high power density of the piston pump makes the piston pump-type hydraulic active suspension system more than 3 kg lighter than that of a traditional hydraulic active suspension system. This lighter weight helps reduce the overall vehicle weight, improves acceleration, braking, and handling performance, while also reducing energy consumption and increasing driving range.

[0116] The small size of the piston pump makes the piston pump-type hydraulic active suspension system occupy less space, which is beneficial for the overall vehicle layout, reduces the space occupied in the vehicle interior, and improves the utilization rate of the vehicle interior space.

[0117] Especially in the five-in-one solution, the two wheels share a single piston pump assembly, which further reduces the size and weight of the system and simplifies the layout.

[0118] Overall vehicle noise is significantly reduced. The low-pulsation characteristics of the piston pump result in operating noise levels more than 5 dB lower for the piston pump-type hydraulic active suspension system compared to traditional hydraulic active suspension systems. Lower noise levels improve cabin quietness and enhance ride comfort.

[0119] The high reliability and long lifespan of the piston pump reduce the failure rate of the piston pump-type hydraulic active suspension system by more than 20% and extend the maintenance cycle by more than 30% compared with the traditional hydraulic active suspension system, thereby reducing the overall vehicle maintenance cost and improving user satisfaction.

[0120] The piston-pump hydraulic active suspension system can work in conjunction with intelligent systems such as anti-drone control systems, vehicle networking systems, and autonomous driving systems to achieve more intelligent suspension control. For example, the system can obtain road surface information ahead through the vehicle networking system and adjust the suspension control strategy in advance; the system can also work with autonomous driving systems to actively adjust the suspension based on the driving path and vehicle speed during autonomous driving, improving ride comfort and safety. The piston-pump hydraulic active suspension system, combined with the anti-drone control system, can cover more than 95% of usage scenarios and operating conditions, offering greater adaptability and providing technical support for achieving higher levels of autonomous driving. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A piston pump type hydraulic active suspension system, characterized in that, It includes a powertrain, a damper assembly, and an accumulator. The damper assembly is provided with a valve control oil circuit, and a solenoid valve is provided on the valve control oil circuit. The damper assembly is connected to the accumulator through the valve control oil circuit. The powertrain is a piston pump assembly, and the piston pump assembly is connected to the damper assembly through a pump control oil circuit. The valve control oil circuit and the pump control oil circuit are arranged in parallel.

2. The piston pump type hydraulic active suspension system according to claim 1, characterized in that, The piston pump assembly includes a piston pump connected to a motor, which is controlled by a controller MCU.

3. The piston pump type hydraulic active suspension system according to claim 2, characterized in that, The piston pump is a bidirectional variable pump, and the pump control oil circuit is a hydraulic line. The piston pump is connected to the upper and lower chambers of the damper assembly through the hydraulic line to form a closed loop.

4. The piston pump type hydraulic active suspension system according to claim 1, characterized in that, The solenoid valves are compression solenoid valves and reset solenoid valves in different valve control oil circuits, and all solenoid valves are proportional solenoid directional valves.

5. A piston pump type hydraulic active suspension system according to claim 4, characterized in that, The pump-controlled oil circuit is the main oil circuit. By adjusting the opening of the solenoid valve with different currents, the flow rate of the main oil circuit is changed, thereby changing the pressure difference between the upper and lower chambers of the damper assembly.

6. A piston pump type hydraulic active suspension system according to claim 1, characterized in that, The piston pump assembly adopts a three-in-one design, consisting of a pump head, a piston pump body, and a controller.

7. A piston pump type hydraulic active suspension system according to claim 1, characterized in that, The piston pump assembly adopts a five-in-one design, consisting of two pump heads, two piston pump bodies, and a controller.

8. A method for operating a piston pump type hydraulic active suspension system, characterized in that, The active suspension system as described in any one of claims 1-7 includes the following steps: Under valve control, the oil flow rate in the main oil circuit is adjusted by controlling the opening of the solenoid valve in the damper assembly with different currents, thereby changing the pressure difference between the upper and lower chambers of the damper. At this time, the piston pump assembly automatically adjusts the output according to the load. In pump control mode, the piston pump assembly controls the main oil circuit flow rate by rotating at a certain speed. It can also automatically adjust the internal swashplate or swing angle according to the load to achieve stepless adjustment of the main oil circuit flow rate. The accumulator adapts to the system oil pressure.

9. The working method of a piston pump type hydraulic active suspension system according to claim 8, characterized in that, It is divided into active control mode and semi-active control mode; In active mode, the piston pump assembly actively performs work and adaptively adjusts the output to control the oil flow in the main oil circuit according to the load. Meanwhile, the accumulator adaptively adjusts according to the system oil pressure to ensure that there are no sudden pressure changes during the entire operation. In semi-active control mode, the piston pump assembly is in a zero-speed control state, applying a reverse torque to the piston to suppress the piston from rotating with the oil, and the solenoid valve in the damper assembly controls the flow of the main oil circuit.

10. A vehicle, characterized in that, The vehicle is equipped with a piston pump type hydraulic active suspension system as described in any one of claims 1-7.

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