Air suspension energy regeneration system and cooperative control method

Abstract

The air suspension energy regeneration system comprises an air spring mechanism, an exhaust port of the air spring mechanism is connected with a piezoelectric proportional valve, and the first output end of the piezoelectric proportional valve is communicated with an expansion generator after passing through an energy accumulator; a second output end of the piezoelectric proportional valve is communicated with the bidirectional turbine power generation module; electric energy generated by the expansion generator and the bidirectional turbine power generation module is rectified by the rectifier module and then charges the capacitor energy storage group, and an electric energy output end of the capacitor energy storage group is merged into a whole vehicle power supply; an ECU controller is further arranged, and the input end of the ECU controller is connected with the detection sensor unit. The control end of the ECU controller is connected with the control end of the piezoelectric proportional valve and the control end of the bidirectional turbine power generation module. The expansion generator and the two-way turbine power generation module are arranged between the high-pressure gas circuit main pipeline between the air spring and the gas storage tank, and recovery of pressure relief energy of the air spring is achieved.

Description

Technical Field

[0001] This invention relates to the field of automotive suspension technology, specifically to an air suspension energy regeneration system and a collaborative control method. Background Technology

[0002] Since its invention in the mid-19th century, air suspension has undergone a century of development, evolving through various forms such as "air spring-airbag composite suspension → semi-active air suspension → central inflation / deflation suspension (i.e., ECAS electronically controlled air suspension system)". Vehicles equipped with adjustable air suspension have ground clearance sensors near the front and rear wheels. Based on the output signals from these sensors, the vehicle's computer determines changes in vehicle height and then controls the air compressor and exhaust valves to automatically compress or extend the springs, thereby lowering or raising the chassis ground clearance to increase high-speed stability or improve passability on complex road conditions.

[0003] Existing air suspension systems suffer from serious energy waste, with compressed air potential energy dissipated through the throttle valve, resulting in slow response speed; solenoid valve adjustment frequency ≤20Hz; and high additional energy consumption, with the air pump consuming 300-500W of power. Summary of the Invention

[0004] I. Technical problems to be solved To address the shortcomings of existing technologies, this invention proposes an air suspension energy regeneration system and collaborative control method that utilizes an expansion generator and a bidirectional turbine power generation module, along with a control method to analyze road surface excitation characteristics in real time and dynamically adjust the ratio between air pressure energy recovery and suspension stiffness control. This achieves rapid energy recovery and dynamic response in the suspension system.

[0005] II. Specific Technical Solutions An air suspension energy regeneration system includes an air spring mechanism, with a piezoelectric proportional valve connected to the exhaust port of the air spring mechanism. The first output end of the piezoelectric proportional valve is connected to an expansion generator via an energy accumulator. The second output terminal of the piezoelectric proportional valve is connected to the bidirectional turbine power generation module; The electrical energy generated by the expander generator and the bidirectional turbine generator module is rectified by the rectifier module to charge the capacitor energy storage group. The electrical energy output terminal of the capacitor energy storage group is connected to the vehicle power supply. It is also equipped with an ECU controller, whose input terminal is connected to the detection sensor unit to collect vehicle driving status data; The control terminals of the ECU controller are connected to the control terminals of the piezoelectric proportional valve and the bidirectional turbine generator module, respectively.

[0006] As an optimization: the detection sensor unit is specifically equipped with a millimeter-wave radar for detecting road surface elevation data; an axle head accelerometer for detecting vehicle tire axle head vibration data; a vehicle body height sensor for detecting air spring mass displacement data; a flow sensor for detecting turbine airflow data in the bidirectional turbine power generation module; a voltage and current sensor for detecting the power output data of the expansion generator and the bidirectional turbine power generation module; and a temperature sensor for detecting the operating temperature data of the expansion generator and the bidirectional turbine power generation module.

[0007] A collaborative control method for an air suspension energy regeneration system, comprising the following steps: Step 1: Start the system and complete sensor initialization; Step 2: Read the real-time detection data from the detection sensor unit; Step 3: Analyze and identify the road surface condition. For flat roads, enter the economic mode and prioritize turbine power generation; for continuous bumpy roads, enter the high-efficiency recovery mode, where the expander generator and the bidirectional turbine power generation module generate electricity together; for emergency braking, enter the safety mode, shut down the expander generator and the bidirectional turbine power generation module, and do not perform energy recovery. Step 4: Determine if the pressure exceeds the limit. If yes, proceed to Step 5; otherwise, proceed to Step 7. Step 5: Activate the bypass valve to release pressure; Step Six: Initiate fault diagnosis. For serious faults, a shutdown alarm will be triggered; for non-serious faults, operation will continue. Step 7: Maintain the status and update the control parameters, then proceed to Step 2.

[0008] As an optimization: the criterion for determining the economic mode is that the vertical acceleration of the air spring is less than or equal to 0.3g, and the piezoelectric proportional valve is set to 30% energy recovery.

[0009] As an optimization: the criterion for the high-efficiency recovery mode is that the vertical acceleration of the air spring is greater than 0.3g, and the piezoelectric proportional valve is set to 70% energy recovery.

[0010] As an optimization: the specific criterion for judging a flat road surface is that the main frequency of the vibration sensor spectrum is <10Hz, and the specific criterion for judging continuous bumps is that the main frequency of the vibration sensor spectrum is >25Hz.

[0011] The beneficial effects of this invention are as follows: An expansion generator and a bidirectional turbine generator module are installed between the high-pressure air main pipeline between the air spring and the air tank. Depending on the vehicle's operating status, the expansion generator or the bidirectional turbine generator module can be selectively activated, or both can be activated simultaneously, to recover the depressurization energy of the air spring. Furthermore, by analyzing the road excitation characteristics in real time, the ratio between air pressure energy recovery and suspension stiffness control is dynamically adjusted to achieve an energy recovery efficiency of 41.2% while maintaining the vehicle's vertical acceleration ≤0.3g. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the system of the present invention.

[0013] Figure 2 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0014] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0015] like Figure 1 As shown: An air suspension energy regeneration system includes an air spring mechanism, which is installed in the high-pressure air main pipeline between the air spring and the air tank, 120±5mm from the air spring outlet. A piezoelectric proportional valve is connected to the exhaust port of the air spring mechanism, and the first output end of the piezoelectric proportional valve is connected to the expansion generator after passing through an accumulator. The second output terminal of the piezoelectric proportional valve is connected to the bidirectional turbine power generation module; The electrical energy generated by the expander generator and the bidirectional turbine generator module is rectified by the rectifier module to charge the capacitor energy storage group. The electrical energy output terminal of the capacitor energy storage group is connected to the vehicle power supply. It also includes an ECU controller, whose input is connected to a detection sensor unit for collecting vehicle driving status data. Specifically, the detection sensor unit includes a millimeter-wave radar for detecting road surface elevation data; an axle head accelerometer for detecting tire axle head vibration data; a vehicle height sensor for detecting air spring mass displacement data; a flow sensor for detecting turbine airflow data in the bidirectional turbine generator module; voltage and current sensors for detecting the power output data of the expander generator and the bidirectional turbine generator module; and a temperature sensor for detecting the operating temperature data of the expander generator and the bidirectional turbine generator module.

[0016] The control terminals of the ECU controller are connected to the control terminals of the piezoelectric proportional valve and the bidirectional turbine generator module, respectively.

[0017] The bidirectional turbine power generation module consists of: titanium alloy turbine blades (Φ45×18mm): 3D printed, with 9 blades, an installation angle of 22°, and a surface roughness Ra≤0.8μm; Permanent magnet brushless motor (outer diameter Φ60mm): Embedded in the turbine housing, with IP67 protection rating. Deep groove ball bearing: axial clearance 50μm, radial clearance 30μm, operating temperature -40℃~150℃ Cooling channel: Spiral water cooling channel inside the shell (coolant flow rate 0.5L / min); Gas connection scheme Upstream interface: The inner diameter of the pipe connecting the air spring is Φ25mm, and the wall thickness is 2mm (6061-T6 aluminum alloy). Install a piezoelectric proportional valve (response time < 5ms), and connect the valve body to the turbine module flange (bolt specification M8×25, 4 holes evenly distributed). Downstream interface: The main gas path is divided into two branches: Branch A (Φ18mm): Straight-through accumulator, with check valve (opening pressure 0.3MPa) Branch B (Φ12mm): Connects to the expansion generator and is equipped with a stepper motor regulating valve. Motor optional Permanent magnet brushless motor (outer diameter Φ60mm).

[0018] Sensor placement Pressure sensor: Installation location: 1 turbine inlet / 1 turbine outlet (Model SMP-131, measuring range 0-1MPa) Sampling frequency: 1kHz, accuracy ±0.25%FS Temperature sensor: PT100 is embedded at the end of the motor winding (10mm from the iron core). Thermocouples are placed in the turbine outlet airflow (response time < 100ms). The specific steps of the above-mentioned coordinated control method for the air suspension energy regeneration system are as follows: Step 1: Start the system and complete sensor initialization; Step 2: Read the real-time detection data from the detection sensor unit; Step 3: Analyze and identify the road surface condition. For flat roads, enter the economic mode, prioritizing turbine power generation; for continuous bumps, enter the high-efficiency recovery mode, where the expander generator and bidirectional turbine power generation module generate electricity together; for emergency braking, enter the safety mode, shutting down the expander generator and bidirectional turbine power generation module, and ceasing energy recovery. The criteria for determining the economic mode are that the vertical acceleration of the air spring is less than or equal to 0.3g, and the piezoelectric proportional valve is set to 30% energy recovery. The criteria for determining the high-efficiency recovery mode are that the vertical acceleration of the air spring is greater than 0.3g, and the piezoelectric proportional valve is set to 70% energy recovery. The specific criteria for determining a flat road surface are that the main frequency of the vibration sensor spectrum is <10Hz, and the specific criteria for determining continuous bumps are that the main frequency of the vibration sensor spectrum is >25Hz.

[0019] Step 4: Determine if the pressure exceeds the limit. If yes, proceed to Step 5; otherwise, proceed to Step 7. Step 5: Activate the bypass valve to release pressure; Step Six: Initiate fault diagnosis. For serious faults, a shutdown alarm will be triggered; for non-serious faults, operation will continue. Step 7: Maintain the status and update the control parameters, then proceed to Step 2.

[0020] When the system starts up, the controller first initializes: loads preset PID parameters, completes sensor zero-point calibration, and pre-charges the supercapacitor to its operating voltage, typically 70% of its rated voltage. This step ensures that all subsystems are in a safe standby state, ready for real-time control.

[0021] Sensor data acquisition and processing stage: The system synchronously acquires signals from multiple sensors at a 10ms cycle. When the flow sensor detects the airflow rate, it immediately classifies the status: below 15L / s is marked as "low energy state," at which point turbine regeneration is shut down to avoid efficiency loss; 15-35L / s maintains the "optimal operating range" setting; and above 35L / s triggers "overload protection" and activates the braking system. Simultaneously, the acceleration sensor data undergoes triple processing: first, high-frequency noise is eliminated through a 20Hz low-pass filter; then, a 0.1-second moving average is calculated; and finally, gravity bias is subtracted to output a standardized vertical acceleration value. The pressure sensor focuses on analyzing the slope of the pressure change (dp / dt). A steep slope (>5bar / s) is detected as an impingement zone, while a sustained negative slope indicates a risk of air leakage.

[0022] Decision-making and control phase: The processed acceleration values ​​and road surface analysis results are input into the decision-making core. Vibration sensor spectrum analysis classifies roads into three categories: Class A smooth road surface (dominant frequency <10Hz), Class B rough road surface (10-25Hz), and Class C bumpy road surface (>25Hz). Key decision points always adhere to the "safety first" principle: as long as the vertical acceleration >0.3g, the system immediately enters stiffness priority mode (proportional valve opening 30%); energy recovery mode (proportional valve opening 70%) is only activated when the acceleration ≤0.3g, temperature <75℃, and flow rate 15-35L / s. Mode switching is achieved through a dynamic PID algorithm, adjusting the proportional valve PWM duty cycle every 10ms.

[0023] Energy Conversion and Safety Management Phase: In energy recovery mode, high-pressure airflow drives the turbine to a speed of 15,000-30,000 RPM, which in turn drives the permanent magnet generator to produce three-phase AC power. After rectification, the AC power is stored in the supercapacitor using a stepped strategy (constant current → constant voltage → float charging). This process is always subject to triple safety monitoring: the temperature subsystem reduces the water pump speed when the temperature difference between the inlet and outlet of the water-cooling channel is <5℃, starts the auxiliary fan when the winding temperature is >75℃, and forces a power reduction when the temperature is >85℃; the electrical subsystem continuously monitors the capacitor's SOC and switches to energy consumption mode when it is >95%; and the mechanical subsystem triggers the pressure relief valve when the speed is >30,000 RPM or the airflow is >40 L / s.

[0024] Performance optimization and looping mechanisms: After each energy conversion, the system calculates the recovery efficiency (η = output electrical energy / air pressure potential energy × 100%) in real time and compares it with the target value of 41.2%. If the efficiency is insufficient, the PID gain is automatically optimized; otherwise, the current parameters are maintained. All monitoring data form a closed-loop feedback. After confirming the temperature status (whether water cooling is activated) and checking the safety boundaries (voltage / flow / speed), the system returns to the sensor acquisition node and starts the next control cycle. When the vehicle is turned off, a safety shutdown procedure is executed: the turbocharger gradually stops, the proportional valve returns to the safe position, the capacitor discharges to the safe voltage, and the operating log is saved for diagnostic analysis.

[0025] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.

Claims

1. An air suspension energy regeneration system, comprising an air spring mechanism, characterized in that: A piezoelectric proportional valve is connected to the exhaust port of the air spring mechanism, and the first output end of the piezoelectric proportional valve is connected to the expansion generator after passing through the accumulator. The second output terminal of the piezoelectric proportional valve is connected to the bidirectional turbine power generation module; The electrical energy generated by the expander generator and the bidirectional turbine generator module is rectified by the rectifier module to charge the capacitor energy storage group. The electrical energy output terminal of the capacitor energy storage group is connected to the vehicle power supply. It is also equipped with an ECU controller, whose input terminal is connected to the detection sensor unit to collect vehicle driving status data; The control terminals of the ECU controller are connected to the control terminals of the piezoelectric proportional valve and the bidirectional turbine generator module, respectively.

2. The air suspension energy regeneration system according to claim 1, characterized in that: The detection sensor unit specifically includes a millimeter-wave radar for detecting road surface elevation data; an axle head accelerometer for detecting vehicle tire axle head vibration data; a vehicle body height sensor for detecting air spring mass displacement data; a flow sensor for detecting turbine airflow data in the bidirectional turbine power generation module; a voltage and current sensor for detecting the power output data of the expansion generator and the bidirectional turbine power generation module; and a temperature sensor for detecting the operating temperature data of the expansion generator and the bidirectional turbine power generation module.

3. The collaborative control method for the air suspension energy regeneration system according to claim 1 or 2, characterized in that, The specific steps are as follows: Step 1: Start the system and complete sensor initialization; Step 2: Read the real-time detection data from the detection sensor unit; Step 3: Analyze and identify the road surface condition. For flat roads, enter the economic mode and prioritize turbine power generation; for continuous bumpy roads, enter the high-efficiency recovery mode, where the expander generator and the bidirectional turbine power generation module generate electricity together; for emergency braking, enter the safety mode, shut down the expander generator and the bidirectional turbine power generation module, and do not perform energy recovery. Step 4: Determine if the pressure exceeds the limit. If yes, proceed to Step 5; otherwise, proceed to Step 7. Step 5: Activate the bypass valve to release pressure; Step Six: Initiate fault diagnosis. For serious faults, a shutdown alarm will be triggered; for non-serious faults, operation will continue. Step 7: Maintain the status and update the control parameters, then proceed to Step 2.

4. The coordinated control method for the air suspension energy regeneration system according to claim 3, characterized in that: The criteria for determining the economic mode are that the vertical acceleration of the air spring is less than or equal to 0.3g, and the piezoelectric proportional valve is set to 30% energy recovery.

5. The coordinated control method for the air suspension energy regeneration system according to claim 3, characterized in that: The criterion for determining the high-efficiency recovery mode is that the vertical acceleration of the air spring is greater than 0.3g, and the piezoelectric proportional valve is set to 70% energy recovery.

6. The coordinated control method for the air suspension energy regeneration system according to claim 3, characterized in that: The specific criteria for judging a flat road surface are that the main frequency of the vibration sensor spectrum is <10Hz, and the specific criteria for judging continuous bumps are that the main frequency of the vibration sensor spectrum is >25Hz.

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