A sightseeing vehicle energy recovery multi-stage conversion method and system

Abstract

The application discloses a sightseeing vehicle energy recovery multistage conversion method and system. The method is controlled by multiple parameters of passenger capacity adjustment parameters and real-time driving state parameters, a multistage conversion strategy is constructed, and an energy recovery operation is performed according to the multistage conversion strategy. The method overcomes the problem of low energy recovery efficiency of the sightseeing vehicle caused by passenger capacity fluctuation, frequent low-speed start-stop and slope driving, dynamically constructs a multistage conversion strategy of energy recovery, effectively improves the recovery utilization rate of short-time high-frequency braking energy of the sightseeing vehicle under the condition of quality fluctuation, and has the advantages of improving passenger comfort.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sightseeing vehicle energy recovery, and particularly relates to a sightseeing vehicle energy recovery multi-stage conversion method and system. BACKGROUND

[0002] With the popularization of the concept of green tourism, electric sightseeing vehicles are increasingly widely used in scenic spots, theme parks and other places. Such vehicles are long-term operated in complex road conditions, such as frequent hill driving, low-speed start-stop and significant passenger load fluctuation, and the difference between the empty vehicle mass and the full vehicle mass can reach several times. Under this working condition, the energy recovery potential generated by the vehicle braking process is huge.

[0003] The existing electric vehicle energy recovery technology is mainly designed for highway driving conditions, and its core is the energy conversion mechanism based on motor reverse rotation power generation. However, this technology has obvious defects when applied to sightseeing vehicles: the kinetic energy generated by single braking of sightseeing vehicles under low-speed frequent start-stop working condition is small, and the traditional technology ignores the difference in energy recovery under different passenger loads of sightseeing vehicles. For example, the recovered energy generated by sightseeing vehicles under the same vehicle speed is significantly different between empty load and full load, and the fixed energy recovery intensity in the traditional technology cannot fully utilize the energy recovery potential of sightseeing vehicles under different passenger loads.

[0004] In view of the above problems, the existing technology needs to be improved. SUMMARY

[0005] The present application aims to solve the problems of low energy recovery efficiency of sightseeing vehicles under complex operating conditions and the inability to adapt to dynamic changes in passenger load, achieve efficient energy recovery of sightseeing vehicles under low-speed and frequent start-stop scenarios, and reduce the operating cost of sightseeing vehicles.

[0006] To achieve the above-mentioned purpose, the present application provides a sightseeing vehicle energy recovery multi-stage conversion method and system, and the technical scheme is as follows:

[0007] Obtain the passenger load adjustment parameter of the sightseeing vehicle during driving, which is calculated based on the real-time passenger load and the rated passenger load; simultaneously collect real-time driving state parameters, including real-time vehicle speed, brake pedal stroke and road slope; according to the passenger load adjustment parameter and the real-time driving state parameter, construct a multi-stage conversion strategy for energy recovery, which includes multi-stage division of energy recovery intensity, multi-stage switching of energy storage path and multi-stage setting of start condition; perform energy recovery operation according to the multi-stage conversion strategy.

[0008] Further, the passenger capacity adjustment parameter of the sightseeing vehicle is obtained by collecting the actual weight of each passenger through a pressure sensor, accumulating the actual weight of all passengers to obtain a real-time passenger capacity, and calculating the ratio of the real-time passenger capacity to the rated passenger capacity to obtain the passenger capacity adjustment parameter.

[0009] Further, in the multi-stage conversion strategy of energy recovery, the multi-stage division of energy recovery intensity includes setting an energy recovery intensity coefficient for representing the size of the energy recovery braking torque, and the larger the value, the larger the energy recovery braking torque; setting an empty threshold and a half-load threshold to divide the sightseeing vehicle into three energy recovery intensity levels; when the passenger capacity adjustment parameter is ≤ the empty threshold, it is defined as the first level; when the empty threshold < the passenger capacity adjustment parameter < the half-load threshold, it is defined as the second level; when the passenger capacity adjustment parameter is ≥ the half-load threshold, it is defined as the third level; when the first level, the energy recovery intensity coefficient is set to a first intensity coefficient; when the second level, the energy recovery intensity coefficient is set to a second intensity coefficient; when the third level, the energy recovery intensity coefficient is set to a third intensity coefficient; wherein the first intensity coefficient is less than the second intensity coefficient, and the second intensity coefficient is less than the third intensity coefficient.

[0010] Further, in the multi-stage conversion strategy of energy recovery, the multi-stage division of energy recovery intensity includes setting an energy recovery intensity coefficient for representing the size of the energy recovery braking torque, and the larger the value, the larger the energy recovery braking torque; setting an empty threshold and a half-load threshold to divide the sightseeing vehicle into three energy recovery intensity levels; when the passenger capacity adjustment parameter is ≤ the empty threshold, it is defined as the first level; when the empty threshold < the passenger capacity adjustment parameter < the half-load threshold, it is defined as the second level; when the passenger capacity adjustment parameter is ≥ the half-load threshold, it is defined as the third level; when the first level, the energy recovery intensity coefficient is set to a first intensity coefficient; when the second level, the energy recovery intensity coefficient is set to a second intensity coefficient; when the third level, the energy recovery intensity coefficient is set to a third intensity coefficient; wherein the first intensity coefficient is less than the second intensity coefficient, and the second intensity coefficient is less than the third intensity coefficient.

[0011] Further, the precondition for performing the energy recovery operation according to the multi-level conversion strategy is that the sightseeing vehicle meets an energy recovery starting condition, and the starting condition is specifically that a real-time vehicle speed is greater than a vehicle speed threshold corresponding to the level, the power battery charge is not more than 95%, and the brake pedal stroke reaches a preset proportion of the total stroke. The multi-level setting of the starting condition is specifically multi-level setting of the vehicle speed threshold, including: when the sightseeing vehicle is in the first level, the energy recovery starting vehicle speed threshold is set to a first vehicle speed; when the sightseeing vehicle is in the second level, the energy recovery starting vehicle speed threshold is set to a second vehicle speed; and when the sightseeing vehicle is in the third level, the energy recovery starting vehicle speed threshold is set to a third vehicle speed. The first vehicle speed is greater than the second vehicle speed, and the second vehicle speed is greater than the third vehicle speed.

[0012] Further, the multi-level conversion strategy of the energy recovery further includes a multi-level compensation mechanism of road slope: based on the obtained road slope value, multi-level slope levels are divided, and corresponding slope coefficients are set; a slope threshold is set, when the slope coefficient is greater than the slope threshold, the passenger capacity adjustment parameter is adjusted in multiple levels according to the slope level, the multi-level adjustment includes a first adjustment coefficient corresponding to a gentle slope and a second adjustment coefficient corresponding to a steep slope, and the second adjustment coefficient is greater than the first adjustment coefficient; the energy recovery strength level is adjusted using the adjusted passenger capacity adjustment parameter.

[0013] Further, the multi-level conversion strategy of the energy recovery further includes a multi-level adjustment mechanism of comfort: a third threshold is set, which is 80% of the half-load threshold; when the passenger capacity adjustment parameter is greater than or equal to the third threshold, the maximum recovery brake torque is limited to be less than or equal to a first brake torque threshold, and the first brake torque threshold is determined based on a third strength coefficient of the third level, which is 80% of the brake force corresponding to the third strength coefficient.

[0014] Further, the application also proposes a sightseeing vehicle energy recovery multi-stage conversion system, comprising: a passenger parameter sensing module composed of a distributed pressure sensor and a data fusion unit, the pressure sensor is independently configured on each seat of the sightseeing vehicle for collecting the actual body weight of each passenger; the data fusion unit is used to accumulate the body weight data to obtain real-time passenger mass and calculate passenger quantity adjustment parameters to provide core input for multi-stage conversion; a state monitoring module configured with a vehicle speed sensor, a brake stroke sensor and a slope instrument for collecting real-time vehicle speed, brake pedal stroke and road slope value to provide working condition basis for multi-stage conversion; a strategy control module including an embedded controller connected with the passenger parameter sensing module and the state monitoring module, the embedded controller has a built-in parameter mapping table for dynamically generating multi-stage conversion instructions for energy recovery according to the received passenger quantity adjustment parameters and real-time driving state parameters, the multi-stage conversion instructions include energy recovery intensity level, storage path level and start condition level; an execution module connected with the strategy control module, including a drive motor, a super capacitor group and a power battery group, for performing kinetic energy-electric energy conversion and multi-stage storage operation according to the multi-stage conversion instructions.

[0015] Further, the multi-stage conversion strategy for energy recovery further includes a scenic route pre-judgment mechanism: obtaining scenic preset route information of the sightseeing vehicle, the scenic preset route information includes site position, road slope change point and curve distribution; obtaining real-time position coordinates of the sightseeing vehicle in the scenic preset route through a positioning module; based on the real-time position coordinates and the current driving direction, matching road condition features within a preset distance in front in the scenic preset route information, the road condition features include whether adjacent to a site, whether there is a slope road section and its slope type; when it is predicted that there is a road condition in front that needs to be decelerated in advance, the energy recovery intensity level is corrected in advance according to the deceleration requirement corresponding to the road condition feature, and the corrected energy recovery intensity level forms a cooperative adjustment mechanism with the passenger quantity adjustment parameter, so that the multi-stage conversion strategy adapts to the predicted braking scene.

[0016] The application has the advantages that the sightseeing vehicle energy recovery multi-stage conversion method and system dynamically constructs a multi-stage conversion strategy for energy recovery, solves the problems of low recovery efficiency and abrupt braking caused by the inability of the traditional scheme to adapt to the change of passenger quantity, and has the advantages of improving energy recovery efficiency and passenger comfort. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description.

[0018] Figure 1 It is a schematic diagram of a sightseeing vehicle energy recovery multi-stage conversion method;

[0019] Figure 2 A structure diagram of a multi-stage conversion system for energy recovery of a sightseeing vehicle is shown in FIG. 1.

[0020] Figure 3 A schematic diagram of a passenger parameter sensing module is shown in FIG. 2.

[0021] Figure 4 A schematic diagram of a state monitoring module is shown in FIG. 3.

[0022] Figure 5 A schematic diagram of a strategy control module is shown in FIG. 4.

[0023] Figure 6 A schematic diagram of an execution module is shown in FIG. 5. DETAILED DESCRIPTION

[0024] The technical solutions in the present application will be described in detail below with reference to the accompanying drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0025] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0026] Generally speaking, the overall mass of the sightseeing vehicle is small, so the change in passenger capacity has a greater impact on the overall mass of the sightseeing vehicle, and the difference between the empty mass and the full mass of the vehicle can be several times. For the energy recovery strategy of the sightseeing vehicle, the existing technology mostly uses single parameter control based on vehicle speed or brake signal, which cannot respond to the large fluctuations in the passenger capacity of the sightseeing vehicle. For example, the energy recovery system of a traditional electric sightseeing vehicle usually sets a uniform recovery intensity coefficient (such as 50% of the rated recovery power of the motor), regardless of whether the passenger capacity is 1 person or 10 people, the braking energy is recovered at the same proportion. This mode has significant defects: when the vehicle is empty, the overall mass is only 60%-70% of that in the full load state, and under the same recovery intensity, the proportion of motor braking force in the total braking force will be too high, resulting in a significant "dragging feeling" during braking. At low speed, this jerk will be amplified when starting and stopping frequently, seriously affecting the riding comfort; when the vehicle is fully loaded, due to the increase of 30%-50% in inertial energy, the fixed recovery intensity cannot match the surge in energy recovery potential, and about 20%-30% of the braking energy is wasted by being converted into heat through mechanical braking, and the wear rate of the mechanical brake pads will increase by 15%-20%. It can be seen that the fixed energy recovery strategy in the traditional technology cannot fully utilize the energy recovery potential of the sightseeing vehicle under different passenger mass changes.

[0027] To this end, as shown in Figure 1 the present application proposes a multi-stage conversion method for energy recovery of a sightseeing vehicle, comprising the following steps: step S1, obtaining a passenger capacity adjustment parameter of the sightseeing vehicle during driving, the passenger capacity adjustment parameter being calculated based on the real-time passenger mass and the rated passenger mass; step S2, synchronously collecting real-time driving state parameters, including real-time vehicle speed, brake pedal stroke and road slope; step S3, constructing a multi-stage conversion strategy for energy recovery according to the passenger capacity adjustment parameter and the real-time driving state parameters, the multi-stage conversion strategy including multi-stage division of energy recovery intensity, multi-stage switching of energy storage path and multi-stage setting of starting conditions; step S4, performing energy recovery operation according to the multi-stage conversion strategy.

[0028] It can be understood that in step S1, the passenger capacity adjustment parameter refers to a parameter calculated based on the real-time passenger mass and the rated passenger mass, which can be specifically obtained by collecting the actual weight of each passenger through a pressure sensor and adding up to obtain the real-time passenger mass, and then performing ratio calculation with the rated passenger mass. This parameter is used to quantify the impact of passenger capacity changes on vehicle mass, so as to adapt to the energy recovery demand under different load conditions.

[0029] In step S2, the real-time driving state parameters include real-time vehicle speed, brake pedal stroke and road slope, which can be specifically collected by using a vehicle speed sensor, a displacement sensor and an inclination sensor, respectively. These parameters are used to reflect the current motion state of the vehicle and provide multi-dimensional input basis for constructing the multi-stage conversion strategy for energy recovery.

[0030] In step S3, the multi-stage conversion strategy for energy recovery refers to real-time correction of the energy recovery strength according to the combined changes of the passenger capacity adjustment parameter and the real-time driving state parameter, which can be realized by a preset parameter mapping table. The purpose is to dynamically match the energy recovery strength with the actual operating conditions of the vehicle, avoiding energy waste or braking impact caused by fixed recovery mode. The preset parameter mapping table takes the passenger capacity adjustment parameter, real-time vehicle speed, and brake pedal stroke as input dimensions, and stores the corresponding energy recovery strength coefficient reference value.

[0031] In step S4, the energy recovery operation refers to the conversion of kinetic energy into electrical energy during braking and storage, which is realized by the cooperation of the super capacitor and the power battery through the driving motor reverse rotation and power generation. The operation ensures the energy storage efficiency under different recovery power through the power distribution mechanism, meeting the pulse energy recovery demand of the sightseeing vehicle under the frequent low-speed start-stop operating condition.

[0032] The core innovation of the present application lies in the multi-parameter cooperative control of the passenger capacity adjustment parameter and the real-time driving state parameter, which constructs a dynamically adjustable multi-stage conversion strategy, and effectively improves the recovery utilization rate of short-time high-frequency braking energy through the hybrid energy storage design of the super capacitor and the power battery. Compared with the prior art, the present application overcomes the problems of low recovery efficiency and poor braking comfort caused by the fluctuation of the passenger capacity in the traditional method, and fully utilizes the energy recovery potential of the sightseeing vehicle under different passenger capacity changes

[0033] Through the above scheme, the present application realizes the adaptive adjustment of the energy recovery system of the sightseeing vehicle to the passenger capacity change. By real-time acquisition of the passenger capacity adjustment parameter and the driving state parameter, a multi-stage conversion strategy for energy recovery is constructed, and the system can realize efficient energy recovery under different passenger capacity states. This method avoids the problems of insufficient recovery when empty and abrupt braking when full in the traditional fixed recovery strategy, and improves the energy utilization efficiency. At the same time, by considering multiple parameters such as vehicle speed, brake pedal stroke, and road slope, the system can better adapt to the complex operating conditions of the sightseeing vehicle, such as frequent slope driving and low-speed start-stop, further optimizing the energy recovery effect. This adaptive energy recovery method based on passenger capacity adjustment not only improves the energy utilization efficiency of the sightseeing vehicle, but also improves the braking performance and ride comfort of the vehicle, providing technical support for the efficient operation of the sightseeing vehicle in complex environments.

[0034] Further, the present application proposes that the actual weight of each passenger is collected by a pressure sensor, the real-time passenger capacity is obtained by accumulating the actual weights of all passengers, and the passenger capacity adjustment parameter is calculated by calculating the ratio of the real-time passenger capacity to the rated passenger capacity.

[0035] It can be understood that the pressure sensor is independently configured at the bottom of each seat. When the passenger is seated, the pressure sensor array under the seat detects the pressure change, converts the analog signal into a digital signal, and transmits it to the data fusion unit. The data fusion unit accumulates the passenger weight data of all seats, and performs ratio operation with the rated passenger mass stored in the control unit to generate a passenger capacity adjustment parameter in the range of 0-1.2.

[0036] Exemplarily, the rated passenger mass of a certain sightseeing vehicle is 1000kg, and the current real-time total passenger mass is 600kg, so the passenger capacity adjustment parameter is 0.6. This value can be used for subsequent construction of multi-stage conversion strategy of energy recovery.

[0037] Through the above technical solution, the application realizes accurate perception and quantification of the passenger capacity of the sightseeing vehicle. The passenger capacity adjustment parameter can accurately reflect the real-time load state of the sightseeing vehicle, and provides a reliable basis for dynamic adjustment of the subsequent multi-stage conversion strategy.

[0038] Further, the application proposes that the multi-stage division of the energy recovery intensity includes: setting an energy recovery intensity coefficient for representing the size of the energy recovery braking torque, and the larger the value is, the larger the corresponding energy recovery braking torque is; setting an empty load threshold and a half load threshold to divide the sightseeing vehicle into three energy recovery intensity levels; when the passenger capacity adjustment parameter is less than or equal to the empty load threshold, it is defined as the first level; when the empty load threshold is less than the passenger capacity adjustment parameter and the passenger capacity adjustment parameter is less than the half load threshold, it is defined as the second level; when the passenger capacity adjustment parameter is greater than or equal to the half load threshold, it is defined as the third level; the energy recovery intensity coefficient is set to a first intensity coefficient when the first level is reached; the energy recovery intensity coefficient is set to a second intensity coefficient when the second level is reached; the energy recovery intensity coefficient is set to a third intensity coefficient when the third level is reached; wherein the first intensity coefficient is less than the second intensity coefficient, and the second intensity coefficient is less than the third intensity coefficient.

[0039] wherein the energy recovery intensity coefficient is defined as K is a dimensionless constant, ranging from 0.5 to 1.2; and the linear relationship between the motor braking torque T b is:

[0040] T b = KT max (1)

[0041] wherein, T max is the maximum output braking torque of the driving motor (unit: N·m), which is determined by the motor characteristic curve, and when K =1.0 corresponds to the standard braking torque under the rated passenger mass T stdThe first intensity coefficient is in the range of 0.5-0.7, the second intensity coefficient is in the range of 0.7-0.9, and the third intensity coefficient is in the range of 0.9-1.2.

[0042] The empty load threshold and the half load threshold are the ratio thresholds of the real-time passenger load and the rated passenger load, and their values can be determined by experimental data, for example, the empty load threshold is set to 30% of the rated passenger load, and the half load threshold is set to 70%.

[0043] Specifically, during the operation of the sightseeing vehicle, the ratio of the real-time passenger load and the rated passenger load is calculated to obtain a passenger load adjustment parameter. When the parameter enters the first level interval, the sightseeing vehicle is in an empty load state, the energy recovery intensity coefficient is set to a low value, and the motor braking torque is reduced to avoid braking drag; when entering the second level interval, the sightseeing vehicle is in a half load state, the intensity coefficient is increased to a medium value, and the energy recovery efficiency and driving smoothness are balanced; when reaching the third level interval, the sightseeing vehicle is in a full load state, and the intensity coefficient is adjusted to the highest value to utilize the large inertia of the vehicle to increase the energy recovery amount.

[0044] For example, the empty load threshold is set to 0.3, the half load threshold is set to 0.7, the sightseeing vehicle is divided into three states of empty load, half load and full load, and the first, second and third levels are respectively defined. When the passenger load adjustment parameter is less than or equal to 0.3, it is defined as the first level; when 0.3

[0045] Through the above technical solution, a smaller recovery intensity is used when the vehicle is empty to avoid the influence of excessive braking on ride comfort; a larger recovery intensity is used when the vehicle is full to fully utilize the braking energy. This multi-level adjustment mechanism not only ensures the energy recovery efficiency, but also takes into account the passenger comfort, effectively solving the problem that the traditional fixed recovery intensity cannot adapt to the change of passenger load.

[0046] Further, the application proposes multi-stage switching of the energy storage path, including: determining a target recovery power based on the energy recovery intensity coefficient, real-time vehicle speed, and brake pedal stroke; setting a first power threshold and a second power threshold, the first power threshold being a maximum instantaneous power value at which the power battery efficiently receives energy, the second power threshold being a trigger power value at which the super capacitor transfers energy to the power battery, and the second power threshold being less than the first power threshold; when the target recovery power ≤ the first power threshold, starting a first-stage storage path: recovering energy directly to the power battery; when the target recovery power > the first power threshold, starting a second-stage storage path: preferentially absorbing peak energy through the super capacitor, and when the recovery power drops below the second power threshold, starting an energy transfer path: transferring the energy stored in the super capacitor to the power battery; the capacity of the super capacitor is adapted to the pulse energy storage demand of the sightseeing vehicle frequently starting and stopping at low speed.

[0047] wherein the target recovery power is calculated by a segmented function driven by a dynamic model, and the specific formula is as follows:

[0048] (2)

[0049] In the formula, is the motor generation efficiency, and the calibration value is 0.85-0.92; K is the energy recovery intensity coefficient; F brake is the braking demand (unit: N), determined by the brake pedal stroke S b S b - F brake mapping table; v is the real-time vehicle speed (unit: m / s); v min is the minimum effective recovery speed.

[0050] Exemplarily, the first power threshold is set to 90% of the maximum allowed charging power of the power battery, for example, when the maximum charging power of the power battery is 50 kW, the first power threshold is 45 kW. The second power threshold is set to 60%-70% of the first power threshold, for example, 30 kW. The capacity of the super capacitor is determined according to the maximum pulse energy sum generated by three consecutive braking of the sightseeing vehicle, for example, when the peak power of single braking is 60 kW and the duration is 2 seconds, the total energy demand is 60 kW x 2 s x 3 = 360 kJ, and the corresponding super capacitor capacity needs to reach 100 F or more.

[0051] Specifically, when the brake pedal stroke increases to cause the target recovery power to exceed 45 kW, the electric energy generated by the drive motor is first input to the super capacitor group, which uses its high power density characteristics to quickly store energy. When the braking intensity weakens and the recovery power falls below 30 kW, the super capacitor transfers energy to the power battery through the bidirectional DC-DC converter at a constant current. In this process, the power battery only receives energy below its maximum charging power, avoiding the risk of efficiency decline or thermal runaway caused by overload. The capacity configuration of the super capacitor enables it to continuously absorb more than three braking pulses, adapting to the working condition characteristics of frequent parking and passenger boarding in scenic areas.

[0052] Through the above technical solution, by setting a power threshold and introducing a super capacitor, the problem of traditional power batteries being unable to efficiently absorb small energy pulses generated by frequent low-speed start-stop is solved. The super capacitor acts as a buffer and can quickly absorb peak energy, preventing the power battery from being damaged due to excessive charging power. At the same time, by transferring the energy stored in the super capacitor to the power battery, efficient use of energy is achieved.

[0053] When the passenger load changes, a fixed speed threshold can cause premature start of recovery in the first level, resulting in braking jerk, or delayed start of recovery in the third level, resulting in energy waste.

[0054] To this end, the present application further proposes that the prerequisite for performing energy recovery operations according to the multi-level conversion strategy is that the sightseeing vehicle meets the energy recovery start condition, which is specifically that the real-time vehicle speed is greater than the vehicle speed threshold corresponding to the level, the power battery charge is not more than 95%, and the brake pedal stroke reaches a preset proportion of the total stroke. The multi-level setting of the start condition is specifically the multi-level setting of the speed threshold, including: when the sightseeing vehicle is in the first level, the energy recovery start speed threshold is set to a first speed; when the sightseeing vehicle is in the second level, the energy recovery start speed threshold is set to a second speed; when the sightseeing vehicle is in the third level, the energy recovery start speed threshold is set to a third speed; wherein the first speed is greater than the second speed, and the second speed is greater than the third speed.

[0055] It can be understood that the first level corresponds to a first speed set to a high value, for example 15 km / h, the second level corresponds to a second speed set to 10 km / h, and the third level corresponds to a third speed set to 5 km / h. The vehicle speed sensor continuously collects the current vehicle speed and compares it with the dynamic threshold, and triggers energy recovery when the vehicle speed exceeds the threshold corresponding to the current passenger load state. The preset proportion of the brake pedal stroke is set to 30% of the stroke amount, and when the brake pedal is depressed by more than this proportion, it is considered as an effective braking signal. The upper limit of the power battery charge is set to 95% to avoid battery life degradation due to overcharging.

[0056] Specifically, at the first level, the vehicle mass is lighter, and the kinetic energy is smaller during braking, so the recovery needs to be started at a higher vehicle speed to ensure sufficient energy absorption and avoid excessive braking force at low speed recovery affecting the smoothness. When the passenger capacity increases to the second level, the vehicle inertia increases, and the vehicle speed threshold is appropriately reduced to 10 km / h, so that the recovery system captures more available energy at a lower vehicle speed. At the third level, the vehicle mass is the largest, and the kinetic energy increases significantly during braking. Reducing the vehicle speed threshold to 5 km / h can start the recovery in advance and fully utilize the high kinetic energy brought by the large mass. By dynamically matching the vehicle speed threshold and the passenger capacity, both the frequent braking impact caused by inefficient recovery when empty and the energy waste when fully loaded are avoided, while ensuring that the battery operates within a safe power range.

[0057] Through the above technical solutions, the energy recovery efficiency and ride comfort are effectively balanced, and the overall performance of the sightseeing vehicle under different passenger capacities is improved.

[0058] Further, the present application proposes a multi-level conversion strategy for energy recovery, which also includes a multi-level compensation mechanism for road slope: based on the obtained road slope value, a multi-level slope level is divided, and a corresponding slope coefficient is set; a slope threshold is set, when the slope coefficient is greater than the slope threshold, the multi-level correction is performed on the passenger capacity adjustment parameter according to the slope level, the multi-level correction includes a first correction coefficient corresponding to a gentle slope and a second correction coefficient corresponding to a steep slope, and the second correction coefficient is greater than the first correction coefficient; the corrected passenger capacity adjustment parameter is used to adjust the energy recovery intensity level.

[0059] It can be understood that the slope coefficient is quantitatively represented by the tangent value of the inclination angle collected by the slope instrument, which accurately reflects the influence of the road slope on the vehicle inertia.

[0060] Exemplarily, the slope threshold is set to 0.087 (corresponding to a slope of 5 degrees), and the multi-level correction coefficient is dynamically configured according to the slope coefficient interval: when the road slope coefficient is between 0.087-0.176 (corresponding to 5-10 degrees, tan10°≈0.176), it is determined as a gentle slope, and the first correction coefficient 1.2 is used; when the slope coefficient exceeds 0.176, it is determined as a steep slope, and the second correction coefficient 1.5 is used to correct the corrected passenger capacity adjustment parameter, which is input into the parameter mapping table, triggering the adjustment of the corresponding energy recovery intensity level, realizing the coordinated adaptation of the slope and the passenger capacity. Specifically, in the slope compensation mechanism: when the road slope is detected to be 8 degrees, the corresponding slope coefficient is tan8°≈0.1405, which is determined as a gentle slope, and the system uses the first correction coefficient 1.2 to correct the passenger capacity adjustment parameter. For example, the original passenger capacity adjustment parameter corresponding to the first level is 0.25, and the corresponding first intensity coefficient is 0.6, after correction, the passenger capacity adjustment parameter becomes 0.25x1.2=0.3, reaching the half-load threshold, and the system automatically switches to the second intensity coefficient 0.8 to execute energy recovery.

[0061] When the road slope is detected to be 12 degrees, the corresponding slope coefficient is tan 12°≈0.2126, which exceeds 0.176, and it is determined to be a steep slope. The system adopts a second correction coefficient 1.5 to correct the passenger capacity adjustment parameter. For example, the originally corresponding passenger capacity adjustment parameter of the second level is 0.6, and the corresponding second intensity coefficient is 0.8. After correction, the passenger capacity adjustment parameter becomes 0.6*1.5=0.9, which exceeds the half-load threshold 0.7, and the system automatically switches to the third intensity coefficient 1.0 to execute energy recovery.

[0062] Through the above technical solutions, the present application realizes the adaptive compensation of the hill climbing working condition. On the downhill section, the recovery intensity is accurately improved through the differential correction of gentle slope and steep slope: the recovery intensity is moderately increased on the gentle slope to utilize the gravitational potential energy, and the recovery intensity is greatly increased on the steep slope to balance the greater inertial impact force. This not only improves the energy recovery efficiency, but also avoids the problem of excessive braking burden on the steep slope section due to insufficient recovery intensity, significantly improving the driving safety. At the same time, the setting of two-level correction coefficients enables the system to flexibly cope with different slope conditions, making the multi-level conversion strategy more accurate and efficient in complex slope scenarios.

[0063] Further, the present application proposes that the multi-level conversion strategy of energy recovery further includes a comfort multi-level adjustment mechanism: a third threshold is set as 80% of the half-load threshold; when the passenger capacity adjustment parameter is greater than or equal to the third threshold, the maximum recovery braking torque is limited to be less than or equal to a first braking torque threshold, and the first braking torque threshold is determined based on a third intensity coefficient under the third level, which is 80% of the braking force corresponding to the third intensity coefficient.

[0064] It can be understood that the third threshold is set to 80% of the half-load threshold, forming a transition interval; the first braking torque threshold is obtained by reducing the braking force corresponding to the third intensity coefficient under the third level by 20%; when the passenger capacity adjustment parameter is between the third threshold and the half-load threshold, the maximum recovery braking torque is forcibly limited to be less than or equal to the first braking torque threshold.

[0065] Specifically, when the passenger capacity adjustment parameter reaches 80% of the half-load threshold, the comfort adjustment mechanism is triggered. At this time, the maximum regenerative braking torque is limited to 80% of the value corresponding to the third level. For example, when the third intensity coefficient corresponds to a braking torque of 500N·m, the first braking torque threshold is 400N·m. This limitation is achieved by adjusting the current output of the motor controller. During the increase in brake pedal travel, when the calculated theoretical braking force exceeds the threshold, the actuator only outputs a braking torque of 400N·m. This mechanism intervenes in advance when the passenger capacity approaches the second level, avoiding braking jerks caused by sudden changes in the intensity coefficient, while retaining 80% of the braking force to ensure basic energy recovery efficiency. The braking force limit value is linked to the passenger capacity status, and the full braking force output of the third intensity coefficient is still maintained at the third level to ensure adaptability under different operating conditions.

[0066] Through the above-mentioned technical solution, this application achieves comfort adjustment during the energy recovery process of sightseeing vehicles. Specifically, by limiting the maximum regenerative braking torque when the passenger load is large, the problem of overly abrupt braking is avoided. This improves passenger comfort while ensuring a certain degree of energy recovery efficiency. In addition, this solution can flexibly adjust the various threshold parameters according to actual needs to adapt to the characteristics of different types of sightseeing vehicles.

[0067] Figure 2 This is a schematic diagram of the structure of a multi-stage conversion system for energy recovery in a sightseeing vehicle. Figure 2 As shown, further, the present application proposes a multi-stage conversion system for energy recovery of a sightseeing vehicle, including a passenger parameter sensing module 100 , a state monitoring module 200 , a strategy control module 300 and an execution module 400 .

[0068] Among them, such as Figure 3 As shown, the passenger parameter sensing module 100 is composed of a distributed pressure sensor 110 and a data fusion unit 120. The pressure sensor 110 is independently installed at the bottom of each seat to collect passenger weight data in real time. The data fusion unit 120 obtains the real-time passenger mass of the entire vehicle by accumulating the pressure values ​​of each seat; Figure 4 As shown, the state monitoring module 200 integrates a vehicle speed sensor 210, a brake stroke sensor 220 and an inclinometer 230. The vehicle speed sensor 210 is installed at the end of the drive axle, the brake stroke sensor 220 is connected to the brake pedal shaft, and the inclinometer 230 is fixed to the middle of the frame; Figure 5 As shown, the strategy control module 300 includes an embedded controller 310, a comfort control unit 320, and a route prediction unit 330. The embedded controller has a built-in mapping table storing the corresponding relationship between passenger capacity adjustment parameters and energy recovery intensity, and generates recovery instructions by receiving real-time passenger mass ratio and vehicle speed data; Figure 6As shown, the execution module 400 includes a drive motor 410, a super capacitor group 420, a power battery group 430, and a bidirectional DC-DC converter 440. The drive motor 410 is mechanically connected to the drive shaft, and the super capacitor group 420 is connected in parallel to the input end of the power battery group 430. The energy capacity of the super capacitor group 420 is designed to be 15% of the energy capacity of the power battery group.

[0069] Specifically, the pressure sensor 110 transmits the passenger weight signal of each seat to the data fusion unit 120, and generates real-time passenger mass data after weighted summation. The ratio of the data to the rated passenger mass is input as a passenger capacity adjustment parameter into the strategy control module 300. In the state monitoring module 200, the wheel speed pulse signal is collected at intervals by the vehicle speed sensor 210, the pedal displacement is detected by the brake stroke sensor 220 using a linear Hall element, and the vehicle pitch angle is measured by the slope instrument 230 through a three-axis accelerometer. The strategy control module 300 matches the energy recovery intensity coefficient in the mapping table according to the real-time passenger capacity adjustment parameter, and calculates the target recovery power in combination with the current vehicle speed and brake stroke. When the target recovery power exceeds the maximum receiving power of the power battery group 430, the control instruction will preferentially guide the energy storage to the super capacitor group 420. In the execution module 400, the drive motor 410 is switched to the generator mode in the braking condition, and the generated three-phase alternating current is rectified and divided into two paths: the power below 45kW is directly input to the power battery group 430, and the power above 45kW is temporarily stored in the super capacitor group through the bidirectional DC / DC converter 440. When the system detects that the recovery power has dropped below 30kW, the energy stored in the super capacitor is charged back to the power battery at a rate of 10kW / s.

[0070] As a preferred embodiment, as shown in FIG. 1, Figures 2-6As shown, the scheme of the present application is implemented as follows: the sightseeing vehicle energy recovery system includes a passenger parameter sensing module 100, a state monitoring module 200, a strategy control module 300 and an execution module 400. In the passenger parameter sensing module 100, the pressure sensor 110 adopts a thin film pressure sensitive element, an independent sensor is embedded at the bottom of each seat, and is connected with a data fusion unit through a parallel circuit. The data fusion unit 120 adopts an accumulator to perform real-time summation operation on the signals of multiple sensors to generate real-time passenger mass. In the state monitoring module 200, the vehicle speed sensor 210 adopts a Hall effect encoder installed at the end of the drive wheel shaft, the brake stroke sensor 220 adopts a linear potentiometer integrated in the brake pedal shaft, and the slope instrument 230 adopts a three-axis accelerometer fixed in the middle of the chassis longitudinal beam. In the strategy control module 300, the passenger capacity-recovery strategy mapping table is stored in the embedded controller 310 in the form of a two-dimensional array, the row index corresponds to the passenger capacity adjustment parameter discretization interval, the column index corresponds to the combined state of vehicle speed and brake stroke, and each cell stores the target recovery power value. In the execution module 400, the drive motor 410 adopts a permanent magnet synchronous motor, the inverter thereof is connected in parallel with the super capacitor group 420, the super capacitor group 420 is composed of multiple groups of wound double-layer capacitors connected in series, the power battery group 430 adopts a lithium iron phosphate battery module, and is connected with the super capacitor group 420 through a bidirectional DC-DC converter 440. The modules are connected through a CAN bus to realize data interaction, and the instruction output end of the strategy control module 300 forms a closed-loop control link with the drive motor controller, the super capacitor charge-discharge controller and the power battery management system.

[0071] Through the above technical scheme, the present application realizes the coordinated sensing of passenger mass and driving state, adapts the energy recovery demand in different working conditions through multiple energy storage media, solves the problems of low recovery efficiency and battery pulse loss caused by passenger capacity fluctuation in the traditional scheme, and ensures the smoothness of the braking process.

[0072] Further, taking Wenzhou Baijia Village Scenic Area as an example, the scenic area is characterized by steep slopes, continuous curves and dense distribution of fixed stations, and the sightseeing vehicle needs to complete multiple acceleration, deceleration and stopping operations in a short distance, and the passenger capacity changes significantly with the tourist flow. In such a scene, the traditional energy recovery technology often has the following problems due to the lack of prediction ability for the road ahead: without pre-sensing the road conditions, the recovery strength is often adjusted passively after entering the downhill section, resulting in excessive initial vehicle speed and relying on mechanical braking intervention, which wastes energy and increases brake pad wear; when approaching the station, if the recovery is started only according to the real-time vehicle speed and brake signal, it is easy to cause impact when stopping due to late deceleration, affecting the passenger riding experience.

[0073] Further, the application proposes that the multi-stage conversion strategy of energy recovery further includes a scenic route prediction mechanism: obtaining scenic preset route information of the sightseeing vehicle, the scenic preset route information including site location, road slope change point and bend distribution; obtaining real-time position coordinates of the sightseeing vehicle in the scenic preset route through a positioning module; matching the deceleration road condition features within a preset distance in front based on the real-time position coordinates and the current driving direction in the scenic preset route information, the deceleration road condition features including the nearby site, the slope road section and the turning road section; when it is predicted that there is a deceleration road condition feature in front, the energy recovery intensity coefficient is corrected, and the corrected energy recovery intensity coefficient forms a cooperative adjustment mechanism with the passenger capacity adjustment parameter, so that the multi-stage conversion strategy adapts to the predicted braking scene.

[0074] Specifically, the scenic preset route information is imported into the strategy control module through vehicle-mounted navigation or cloud download. The scenic preset route information is stored in the form of electronic map data, including the latitude and longitude coordinates of each site, the position information of the road slope change point and the bend distribution. At the same time, the algorithm built-in the strategy control module parses these information into structured data to form a road condition feature database. During the operation of the sightseeing vehicle in the scenic area, the Beidou / GPS dual-mode positioning module collects the position coordinates of the vehicle in real time at a frequency of 10 Hz, and combines the vehicle driving direction information obtained by the vehicle-mounted inertial measurement unit to dynamically map the real-time position of the vehicle to the scenic preset route. Based on the real-time position coordinates, the strategy control module calculates the distance between the vehicle and the road condition feature points such as the site in front and the start point of the slope, and judges the road condition features within a preset distance in front. The preset distance is usually set to 50-200 meters, which can be adaptively adjusted according to the vehicle driving speed and the passenger capacity adjustment parameter. When the system predicts that the vehicle is about to enter the deceleration area, such as within 150 meters of the scenic site, or about to enter the downhill section 100 meters in front, the strategy control module starts different adjustment strategies according to the predicted road condition type:

[0075] Nearby site scene: if the front is a scenic site, the system adjusts the energy recovery intensity coefficient to the upper limit value corresponding to the current passenger capacity according to the current passenger capacity adjustment parameter and the remaining distance in advance. For example, in the second level, the normal energy recovery intensity coefficient is 0.7, and when it is predicted that it will enter the site, the intensity coefficient is adjusted to 0.9 in advance, more kinetic energy is recovered by using the motor, so that the vehicle smoothly decelerates to the site parking, reducing the intervention of mechanical braking.

[0076] Downhill section scene: If the front is a downhill section, the system first corrects the passenger capacity adjustment parameter according to the slope type (gentle slope or steep slope) and the slope size. For example, for a steep slope section with a slope greater than 10°, multiply the passenger capacity adjustment parameter by a correction coefficient of 1.2; then combine the corrected passenger capacity adjustment parameter to increase the energy recovery intensity coefficient synchronously, so that the vehicle can establish enough braking force before entering the downhill section, continuously recover energy during the downhill process, and avoid frequent use of mechanical braking due to excessive speed.

[0077] During the entire adjustment process, the corrected energy recovery intensity coefficient and the real-time collected passenger capacity adjustment parameter, vehicle speed, brake pedal stroke and other parameters jointly act on the multi-stage conversion strategy. The strategy control module calculates the target recovery power in real time through an optimization algorithm, and sends instructions to the execution module to control the power generation torque of the drive motor and the energy storage path of the super capacitor and power battery, ensuring that the energy recovery process is highly matched with the vehicle driving state and road condition demand, and achieving efficient and smooth energy recovery control.

[0078] The above only describes the embodiments of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for energy recovery multi-stage conversion of a sightseeing vehicle, characterized in that, The method comprises the following steps: Obtaining the passenger capacity adjustment parameter of the sightseeing vehicle during driving, which is calculated based on the real-time passenger capacity and the rated passenger capacity; Synchronously collecting real-time driving state parameters, including real-time vehicle speed, brake pedal stroke and road slope; According to the passenger capacity adjustment parameter and the real-time driving state parameter, a multi-level conversion strategy for energy recovery is constructed, which includes multi-level division of energy recovery intensity, multi-level switching of energy storage path and multi-level setting of starting condition; According to the multi-level conversion strategy, the energy recovery operation is performed; The multi-level division of energy recovery intensity includes: Setting an energy recovery intensity coefficient to represent the size of the energy recovery braking torque, the larger the value, the larger the energy recovery braking torque; Setting an empty load threshold and a half load threshold to divide the sightseeing vehicle into three energy recovery intensity levels; when the passenger capacity adjustment parameter is less than or equal to the empty load threshold, it is defined as the first level; when the empty load threshold is less than the passenger capacity adjustment parameter and the passenger capacity adjustment parameter is less than the half load threshold, it is defined as the second level; when the passenger capacity adjustment parameter is greater than or equal to the half load threshold, it is defined as the third level; When the first level is reached, the energy recovery intensity coefficient is set to the first intensity coefficient; When the second level is reached, the energy recovery intensity coefficient is set to the second intensity coefficient; When the third level is reached, the energy recovery intensity coefficient is set to the third intensity coefficient; Wherein, the first intensity coefficient is less than the second intensity coefficient, and the second intensity coefficient is less than the third intensity coefficient; The multi-level conversion strategy for energy recovery also includes a multi-level compensation mechanism for road slope: Based on the obtained road slope value, multi-level slope levels are divided, and corresponding slope coefficients are set; Setting a slope threshold, when the slope coefficient is greater than the slope threshold, the passenger capacity adjustment parameter is multi-level corrected according to the slope level, the multi-level correction includes a first correction coefficient corresponding to a gentle slope and a second correction coefficient corresponding to a steep slope, and the second correction coefficient is greater than the first correction coefficient; The energy recovery intensity level is adjusted using the corrected passenger capacity adjustment parameter; It also includes a multi-level adjustment mechanism for comfort: Setting a third threshold, which is 80% of the half load threshold; When the passenger capacity adjustment parameter is greater than or equal to the third threshold, the maximum recovery braking torque is limited to be less than or equal to the first braking torque threshold, which is determined based on the third intensity coefficient of the third level, which is 80% of the braking force corresponding to the third intensity coefficient.

2. The method of claim 1, wherein, The method for obtaining the passenger capacity adjustment parameter of the sightseeing vehicle includes: collecting the actual weight of each passenger through a pressure sensor, adding up the actual weights of all passengers to obtain the real-time passenger capacity, and calculating the ratio of the real-time passenger capacity to the rated passenger capacity to obtain the passenger capacity adjustment parameter.

3. The method of claim 1, wherein, The multi-level switching of the energy storage path includes: Determine the target recovery power based on the energy recovery intensity coefficient, real-time vehicle speed and brake pedal stroke; Setting a first power threshold and a second power threshold, the first power threshold is the maximum instantaneous power value of the high-efficiency energy receiving of the power battery, and the second power threshold is the trigger power value of the energy transfer from the super capacitor to the power battery, and the second power threshold is less than the first power threshold; When the target recovery power is less than or equal to a first power threshold, a first storage path is started: the recovered energy is directly stored in the power battery; When the target recovery power is greater than the first power threshold, a second storage path is started: the peak energy is preferentially absorbed by the super capacitor, and when the recovery power is reduced to below a second power threshold, an energy transfer path is started: the energy stored in the super capacitor is transferred to the power battery; The capacity of the super capacitor is adapted to the pulse energy storage requirements of the sightseeing vehicle frequent low-speed start-stop.

4. The method of claim 1, wherein, The starting condition is a prerequisite for the multi-stage conversion strategy to perform energy recovery operations, and the starting condition includes: The real-time vehicle speed is greater than the vehicle speed threshold corresponding to the level, the power battery power is not more than 95%, and the brake pedal stroke reaches a preset proportion of the total stroke; The multi-stage setting of the starting condition is a multi-stage setting of the vehicle speed threshold, including When the sightseeing vehicle is in the first level, the energy recovery starting vehicle speed threshold is set to a first vehicle speed; When the sightseeing vehicle is in the second level, the energy recovery starting vehicle speed threshold is set to a second vehicle speed; When the sightseeing vehicle is in the third level, the energy recovery starting vehicle speed threshold is set to a third vehicle speed; Wherein the first vehicle speed is greater than the second vehicle speed, and the second vehicle speed is greater than the third vehicle speed.

5. A multi-stage conversion system for energy recovery of a sightseeing vehicle, for performing the method of any one of claims 1-4, characterized in that, It includes: The passenger parameter sensing module is composed of a distributed pressure sensor and a data fusion unit, the pressure sensor is independently configured on each seat of the sightseeing vehicle for collecting the actual weight of each passenger, and the data fusion unit is used to accumulate the weight data to obtain the real-time passenger mass and calculate the passenger capacity adjustment parameter, which provides the core input for multi-stage conversion; The state monitoring module is provided with a vehicle speed sensor, a brake stroke sensor and an inclinometer for collecting real-time vehicle speed, brake pedal stroke and road slope value, which provides the working condition basis for multi-stage conversion; The strategy control module includes an embedded controller connected with the passenger parameter sensing module and the state monitoring module, the embedded controller has a built-in parameter mapping table for dynamically generating multi-stage conversion instructions for energy recovery according to the received passenger capacity adjustment parameter and real-time driving state parameter, the multi-stage conversion instructions include energy recovery intensity level, storage path level and starting condition level; The execution module is connected with the strategy control module and includes a drive motor, a super capacitor group and a power battery group for performing kinetic energy-electric energy conversion and multi-stage storage operation according to the multi-stage conversion instructions.

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