Multistage conversion method and system for energy recovery of sightseeing vehicle

Abstract

The invention discloses a sightseeing vehicle energy recovery multistage conversion method and system, and the method comprises the steps: building a multistage conversion strategy through the multi-parameter cooperative control of a passenger capacity adjustment parameter and a real-time driving state parameter, and executing the energy recovery operation according to the multistage conversion strategy. According to the method, the problem that the energy recovery efficiency is low due to passenger carrying quality fluctuation, frequent low-speed start and stop and ramp running of the sightseeing vehicle is solved, and the recycling rate of short-time high-frequency braking energy of the sightseeing vehicle under the condition of quality fluctuation is effectively increased by dynamically constructing a multi-stage conversion strategy for energy recovery; and meanwhile, the advantage of improving the comfort of passengers is also achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy recovery for sightseeing vehicles, and in particular to a multi-stage conversion method and system for energy recovery for sightseeing vehicles. Background Art

[0002] With the growing popularity of green tourism, electric sightseeing vehicles are increasingly being used in scenic spots, theme parks, and other locations. These vehicles are often exposed to complex road conditions, such as frequent hill driving, slow-speed starts and stops, and significant fluctuations in passenger load. The difference in vehicle mass between an empty and fully loaded vehicle can be several times greater. Under these operating conditions, the energy recovery potential generated during braking is enormous.

[0003] Existing electric vehicle energy recovery technology is mainly designed for highway driving conditions. Its core is an energy conversion mechanism based on motor reverse power generation. However, this technology exposes obvious defects when applied to sightseeing vehicles: under low-speed and frequent start-stop conditions, the kinetic energy generated by a single braking is relatively small, and traditional technology ignores the differences in energy recovery under changes in the passenger mass of sightseeing vehicles. For example, at the same speed, the recovered energy generated by an empty and fully loaded sightseeing vehicle varies greatly. The fixed energy recovery intensity in traditional technology cannot fully utilize the energy recovery potential of sightseeing vehicles under different passenger mass changes.

[0004] In view of the above problems, the existing technology is in urgent need of improvement. Summary of the Invention

[0005] The present invention aims to solve the problem of low energy recovery efficiency and inability to adapt to dynamic changes in passenger mass in sightseeing vehicles under complex operating conditions, realize efficient energy recovery of sightseeing vehicles in low-speed and frequent start-stop scenarios, and reduce the operating costs of sightseeing vehicles.

[0006] To achieve the above objectives, the present application provides a multi-stage conversion method and system for energy recovery in a sightseeing vehicle, the technical solution of which is as follows: During driving, the passenger capacity adjustment parameters of the sightseeing vehicle are obtained, and the passenger capacity adjustment parameters are calculated based on the real-time passenger capacity and the rated passenger capacity; real-time driving status parameters are synchronously collected, including real-time vehicle speed, brake pedal travel and road slope; based on the passenger capacity adjustment parameters and real-time driving status parameters, a multi-level conversion strategy for energy recovery is constructed, and the multi-level conversion strategy includes multi-level division of energy recovery intensity, multi-level switching of energy storage paths and multi-level setting of start-up conditions; and energy recovery operations are performed according to the multi-level conversion strategy.

[0007] Furthermore, obtaining the passenger capacity adjustment parameter of the sightseeing bus includes: collecting the actual weight of each passenger through a pressure sensor, accumulating the actual weight of all passengers to obtain the real-time passenger mass, and calculating the ratio of the real-time passenger mass to the rated passenger mass to obtain the passenger capacity adjustment parameter.

[0008] Furthermore, in the multi-level conversion strategy of energy recovery, the multi-level division of energy recovery intensity includes: setting an energy recovery intensity coefficient to characterize the size of the energy recovery braking torque, the larger the value, the larger the corresponding 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 ≤ the empty load threshold, it is defined as the first level; when the empty load threshold < the passenger capacity adjustment parameter < the half-load threshold, it is defined as the second level; when the passenger capacity adjustment parameter ≥ the half-load threshold, it is defined as the third level; at the first level, the energy recovery intensity coefficient is set to the first intensity coefficient; at the second level, the energy recovery intensity coefficient is set to the second intensity coefficient; at the third level, 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.

[0009] Furthermore, the multi-stage switching of the energy storage path in the multi-stage conversion strategy of energy recovery includes: determining the target recovery power based on the energy recovery intensity coefficient, the real-time vehicle speed and the brake pedal stroke; setting a first power threshold and a second power threshold, the first power threshold being the maximum instantaneous power value for the power battery to efficiently receive energy, the second power threshold being the trigger power value for the supercapacitor to transfer energy to the power battery, and the second power threshold being less than the first power threshold; when the target recovery power is ≤ the first power threshold, starting the first-level storage path: the recovered energy is directly stored in the power battery; when the target recovery power is greater than the first power threshold, starting the second-level storage path: the peak energy is preferentially absorbed through the supercapacitor, and when the recovered power drops below the second power threshold, starting the energy transfer path: the energy stored in the supercapacitor is transferred to the power battery; the capacity of the supercapacitor is adapted to the pulse energy storage requirements of the sightseeing vehicle's frequent low-speed starting and stopping.

[0010] Furthermore, the prerequisite for executing the energy recovery operation according to the multi-level conversion strategy is that the sightseeing vehicle meets the energy recovery start conditions, and the start conditions are specifically: the real-time vehicle speed is greater than the speed threshold of the corresponding level, the power of the power battery does not exceed 95%, and the brake pedal stroke reaches a preset proportion of its total stroke; the multi-level setting of the start conditions 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 the first speed; when the sightseeing vehicle is in the second level, the energy recovery start speed threshold is set to the second speed; when the sightseeing vehicle is in the third level, the energy recovery start speed threshold is set to the third speed; wherein the first speed is greater than the second speed, and the second speed is greater than the third speed.

[0011] Furthermore, the multi-level conversion strategy for energy recovery also includes a multi-level compensation mechanism for road slope: dividing the slope grade into multiple levels based on the acquired road slope value, and setting the corresponding slope coefficient; setting a slope threshold, and when the slope coefficient is greater than the slope threshold, performing multi-level correction on the passenger capacity adjustment parameter according to the slope grade, 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; and using the corrected passenger capacity adjustment parameter to adjust the energy recovery intensity level.

[0012] Furthermore, the multi-stage conversion strategy for energy recovery also includes a multi-stage comfort adjustment mechanism: setting a third threshold, which is 80% of the half-load threshold; when the passenger capacity adjustment parameter is ≥ the third threshold, limiting the maximum recovery braking torque to ≤ the first braking torque threshold, which is determined based on the third intensity coefficient of the third level, and is 80% of the braking force corresponding to the third intensity coefficient.

[0013] Furthermore, the present 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 being independently configured on each seat of the sightseeing vehicle for collecting the actual weight of each passenger; the data fusion unit being configured to accumulate weight data to obtain real-time passenger mass and calculate passenger capacity adjustment parameters, providing core input for multi-stage conversion; a state monitoring module, configured with a vehicle speed sensor, a brake travel sensor, and an inclinometer, for collecting real-time vehicle speed, brake pedal travel, and road slope values, providing a working condition basis for multi-stage conversion; a strategy control module, comprising an embedded controller, connected to the passenger parameter sensing module and the state monitoring module, the embedded controller having a built-in parameter mapping table, for dynamically generating multi-stage conversion instructions for energy recovery based on the received passenger capacity adjustment parameters and real-time driving state parameters, the multi-stage conversion instructions including an energy recovery intensity level, a storage path level, and a start condition level; an execution module, connected to the strategy control module, comprising a drive motor, a supercapacitor group, and a power battery group, for performing kinetic energy-electrical energy conversion and multi-stage storage operations according to the multi-stage conversion instructions.

[0014] Furthermore, the multi-stage conversion strategy for constructing energy recovery also includes a scenic area route prediction mechanism: obtaining the scenic area preset route information for the sightseeing vehicle, the scenic area preset route information including the site location, road slope change points and curve distribution; obtaining the real-time position coordinates of the sightseeing vehicle in the scenic area preset route through the positioning module; based on the real-time position coordinates and the current driving direction, matching the road condition characteristics within a preset distance ahead in the scenic area preset route information, the road condition characteristics including whether it is close to the site, whether there is a slope section and its slope type; when it is predicted that there is a road condition ahead that requires early deceleration, the energy recovery intensity level is corrected in advance according to the deceleration demand corresponding to the road condition characteristics, and the corrected energy recovery intensity level forms a coordinated adjustment mechanism with the passenger capacity adjustment parameter, so that the multi-stage conversion strategy adapts to the predicted braking scenario.

[0015] The beneficial effect of the present application is that it provides a multi-stage conversion method and system for energy recovery of sightseeing vehicles, which solves the problems of low recovery efficiency and abrupt braking caused by the inability of traditional solutions to adapt to changes in passenger capacity by dynamically constructing a multi-stage conversion strategy for energy recovery. It has the advantages of improving energy recovery efficiency and passenger comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art.

[0017] Figure 1 A schematic diagram of a multi-stage conversion method for energy recovery in a sightseeing vehicle; Figure 2 This is a schematic diagram of the structure of a multi-stage conversion system for energy recovery in a sightseeing vehicle; Figure 3 This is a schematic diagram of the passenger parameter perception module; Figure 4 This is a schematic diagram of the condition monitoring module; Figure 5 Schematic diagram of the strategy control module; Figure 6 Schematic diagram of the execution module. DETAILED DESCRIPTION

[0018] The technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. The components of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely 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 making creative work are within the scope of protection of this application.

[0019] It should be noted that similar reference numerals 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 or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0020] Generally speaking, sightseeing buses have a relatively low overall mass, so changes in passenger capacity significantly impact their overall mass. The difference in mass between an empty and fully loaded vehicle can be several times greater. Existing technologies for energy recovery strategies for sightseeing buses often employ single-parameter control based on vehicle speed or braking signals, making them incapable of responding to significant fluctuations in passenger capacity. For example, the energy recovery systems of traditional electric sightseeing buses typically employ a uniform recovery intensity coefficient (e.g., 50% of the motor's rated recovery power), recovering braking energy at the same rate regardless of whether the passenger capacity is one or ten. This model has significant flaws: when the vehicle is unloaded, its mass is only 60%-70% of that when fully loaded. At the same recuperation intensity, the proportion of electric braking force to total braking force is higher, resulting in a noticeable "drag" during braking. This jerkiness is amplified during frequent low-speed starts and stops, seriously affecting ride comfort. When the vehicle is fully loaded, the inertial kinetic energy increases by 30%-50%, and the fixed recuperation intensity cannot match the surge in energy recovery potential. Approximately 20%-30% of the braking energy can only be converted into heat energy through mechanical braking, and the wear rate of the mechanical brake pads will accelerate by 15%-20%. Therefore, the fixed energy recovery strategy used in traditional technologies cannot fully utilize the energy recovery potential of sightseeing vehicles with varying passenger masses.

[0021] In this regard, Figure 1As shown, the present application proposes a multi-stage conversion method for energy recovery of a sightseeing vehicle, which has the following steps: Step S1, obtaining the passenger capacity adjustment parameter of the sightseeing vehicle during driving, and the passenger capacity adjustment parameter is 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 travel and road slope; Step S3, constructing a multi-stage conversion strategy for energy recovery based on the passenger capacity adjustment parameter and the real-time driving state parameter, 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.

[0022] It can be understood that in step S1, the passenger capacity adjustment parameter refers to the parameter calculated based on the real-time passenger mass and the rated passenger mass. Specifically, the actual weight of each passenger can be collected by a pressure sensor and the real-time passenger mass can be accumulated and then calculated by ratio with the rated passenger mass. This parameter is used to quantify the impact of changes in passenger capacity on vehicle mass, so as to adapt to the energy recovery requirements under different load conditions.

[0023] In step S2, the real-time driving status parameters include real-time vehicle speed, brake pedal travel and road slope, which can be collected by 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 a multi-dimensional input basis for constructing a multi-level conversion strategy for energy recovery.

[0024] In step S3, establishing a multi-level energy recuperation conversion strategy involves real-time adjustment of the energy recuperation intensity based on the combined changes in the passenger capacity adjustment parameter and the real-time driving state parameter. This is achieved through a preset parameter mapping table. Its function is to dynamically match the energy recuperation intensity with the actual vehicle operating conditions, avoiding energy waste or braking shock caused by a fixed recuperation mode. The preset parameter mapping table uses the passenger capacity adjustment parameter, real-time vehicle speed, and brake pedal travel as input dimensions and stores corresponding energy recuperation intensity coefficient baseline values.

[0025] In step S4, executing the energy recovery operation means converting the kinetic energy during braking into electrical energy and storing it. This is achieved by driving the motor to reverse and generate electricity in conjunction with the coordinated energy storage of the supercapacitor and the power battery. This operation ensures the energy storage efficiency under different recovery powers through the power distribution mechanism, meeting the pulse energy recovery requirements under the frequent low-speed start-stop conditions of the sightseeing vehicle.

[0026] The core innovation of this application lies in the construction of a dynamically adjustable multi-stage conversion strategy through the multi-parameter coordinated control of passenger capacity adjustment parameters and real-time driving status parameters. At the same time, through the hybrid energy storage design of supercapacitors and power batteries, the recovery rate of short-term high-frequency braking energy is effectively improved. Compared with the existing technology, this application overcomes the problems of low recovery efficiency and poor braking comfort caused by passenger capacity fluctuations in traditional methods, and fully utilizes the energy recovery potential of sightseeing vehicles under different passenger mass changes. Through the above scheme, the present application realizes the adaptive adjustment of the energy recovery system of the sightseeing vehicle to the changes in passenger capacity. By acquiring the passenger capacity adjustment parameters and driving state parameters in real time to construct a multi-level conversion strategy for energy recovery, the system can achieve efficient energy recovery under different passenger load conditions. This method avoids the problems of insufficient recovery when idling and abrupt braking when fully loaded in traditional fixed recovery strategies, thereby improving energy utilization efficiency. At the same time, by considering multi-dimensional parameters such as vehicle speed, brake pedal travel 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, and further optimize 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.

[0027] Furthermore, the present application proposes to collect the actual weight of each passenger through a pressure sensor, accumulate the actual weights of all passengers to obtain the real-time passenger mass, and calculate the ratio of the real-time passenger mass to the rated passenger mass to obtain the passenger capacity adjustment parameter.

[0028] As you can understand, pressure sensors are independently located under each seat. When a passenger sits down, the pressure sensor array beneath 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 for all seats and calculates the ratio with the rated passenger weight stored in the control unit to generate a passenger capacity adjustment parameter within the range of 0-1.2.

[0029] For example, if a sightseeing vehicle has a rated passenger capacity of 1000 kg and a current total passenger capacity of 600 kg, the passenger capacity adjustment parameter is 0.6. This value can be used to subsequently construct a multi-stage conversion strategy for energy recovery.

[0030] Through the above technical solution, this application realizes the accurate perception and quantification of the sightseeing vehicle passenger capacity. The passenger capacity adjustment parameter can accurately reflect the real-time load status of the sightseeing vehicle, providing a reliable basis for the dynamic adjustment of the subsequent multi-level conversion strategy.

[0031] Furthermore, the present application proposes that the multi-level division of the energy recovery intensity includes: setting an energy recovery intensity coefficient to characterize the magnitude of the energy recovery braking torque, the larger the value, the larger the corresponding 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 ≤ the empty load threshold, it is defined as the first level; when the empty load threshold < the passenger capacity adjustment parameter < the half load threshold, it is defined as the second level; when the passenger capacity adjustment parameter ≥ the half load threshold, it is defined as the third level; at the first level, the energy recovery intensity coefficient is set to the first intensity coefficient; at the second level, the energy recovery intensity coefficient is set to the second intensity coefficient; at the third level, 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.

[0032] The energy recovery intensity coefficient is defined as K is a dimensionless constant ranging from 0.5 to 1.2; it is related to the motor torque T b The linear relationship is: T b = KT max (1) Where, T max is the maximum output braking torque of the drive motor (unit: N·m), which is determined by the motor characteristic curve. K =1.0 corresponds to the standard braking torque at rated passenger mass T std The first strength coefficient ranges from 0.5 to 0.7, the second strength coefficient ranges from 0.7 to 0.9, and the third strength coefficient ranges from 0.9 to 1.2.

[0033] Among them, the no-load threshold and the half-load threshold are the ratio thresholds of the real-time passenger mass to the rated passenger mass, and their sizes can be determined through experimental data. For example, the no-load threshold is set to 30% of the rated passenger mass, and the half-load threshold is set to 70%.

[0034] Specifically, during the operation of the sightseeing vehicle, the ratio of the passenger mass to the rated passenger mass is calculated in real time to obtain the passenger capacity adjustment parameter. When this parameter enters the first level range, the sightseeing vehicle is in an unloaded state, and the energy recovery intensity coefficient is set to a low value, reducing the motor torque to avoid brake drag. When entering the second level range, the sightseeing vehicle is in a half-loaded state, and the intensity coefficient is increased to a medium value, balancing energy recovery efficiency and driving smoothness. When reaching the third level range, the sightseeing vehicle is in a fully loaded state, and the intensity coefficient is adjusted to the highest value, utilizing the vehicle's greater inertia to increase energy recovery.

[0035] For example, the empty threshold is set at 0.3 and the half-load threshold is set at 0.7, dividing the sightseeing vehicle into three states: empty, half-loaded, and fully loaded, corresponding to levels one, two, and three, respectively. When the passenger capacity adjustment parameter is ≤ 0.3, it is defined as level one; when 0.3 < passenger capacity adjustment parameter < 0.7, it is defined as level two; and when the passenger capacity adjustment parameter is ≥ 0.7, it is defined as level three. In level one, the energy recovery intensity coefficient is set to 0.5; in level two, the energy recovery intensity coefficient is set to 0.7; and in level three, the energy recovery intensity coefficient is set to 0.9.

[0036] This technical solution uses a lower recuperation intensity when the vehicle is unladen, preventing abrupt braking that could affect ride comfort; while a higher recuperation intensity is used when the vehicle is fully laden, fully utilizing braking energy. This multi-level adjustment mechanism ensures both energy recovery efficiency and passenger comfort, effectively resolving the issue of traditional fixed recuperation intensity being unable to adapt to changes in passenger load.

[0037] Furthermore, the present application proposes multi-level switching of energy storage paths, including: determining the target recovery power based on the energy recovery intensity coefficient, real-time vehicle speed and brake pedal travel; setting a first power threshold and a second power threshold, the first power threshold being the maximum instantaneous power value for the power battery to efficiently receive energy, and the second power threshold being the trigger power value for the supercapacitor to transfer energy to the power battery, and the second power threshold being less than the first power threshold; when the target recovery power is ≤ the first power threshold, starting the first-level storage path: the recovered energy is directly stored in the power battery; when the target recovery power is greater than the first power threshold, starting the second-level storage path: peak energy is preferentially absorbed through the supercapacitor, and when the recovered power drops below the second power threshold, starting the energy transfer path: the energy stored in the supercapacitor is transferred to the power battery; the capacity of the supercapacitor is adapted to the pulse energy storage requirements of the sightseeing vehicle's frequent low-speed starting and stopping.

[0038] The target recovery power is calculated using a piecewise function driven by a dynamic model. The specific formula is as follows: (2) Where, The motor power generation efficiency is calibrated to 0.85-0.92; K is the energy recovery intensity coefficient; F brake is the braking demand force (unit: N), which is determined by the brake pedal travel S b By setting S b - F brake Mapping table confirmed; v is the real-time vehicle speed (unit: m / s);v min This is the minimum effective recovery speed.

[0039] Exemplarily, the first power threshold is set at 90% of the maximum allowable charging power of the power battery. For example, when the maximum charging power of the power battery is 50kW, the first power threshold is 45kW. The second power threshold is set at 60%-70% of the first power threshold, for example, 30kW. The capacity of the supercapacitor is determined based on the sum of the maximum pulse energy generated by three consecutive braking operations of the sightseeing vehicle. For example, when the peak power of a single braking operation is 60kW and lasts for 2 seconds, the total energy requirement is 60kW×2s×3=360kJ, and the corresponding supercapacitor capacity needs to reach more than 100F.

[0040] Specifically, when the increase in brake pedal stroke causes the target recovery power to exceed 45kW, the electrical energy generated by the drive motor is first input into the supercapacitor group, which uses its high power density characteristics to quickly store energy. When the braking intensity weakens and the recovery power drops below 30kW, the supercapacitor transfers energy to the power battery at a constant current through a bidirectional DC-DC converter. During this process, the power battery only receives energy below its maximum charging power, avoiding the risk of efficiency loss or thermal runaway due to overload. The capacity configuration of the supercapacitor enables it to absorb more than three braking pulses in a row, adapting to the operating conditions of frequent stops and boarding in scenic areas.

[0041] The above technical solution, by setting a power threshold and introducing a supercapacitor, solves the problem of traditional power batteries' difficulty in efficiently absorbing the small energy pulses generated by frequent low-speed starts and stops. Acting as a buffer, the supercapacitor quickly absorbs peak energy, preventing damage to the power battery due to excessive charging power. Furthermore, by transferring the energy stored in the supercapacitor to the power battery, efficient energy utilization is achieved.

[0042] When the passenger mass changes, the fixed speed threshold may cause premature start of regeneration in the first level, resulting in braking jerking, or delayed start of regeneration in the third level, resulting in energy waste.

[0043] In this regard, the present application further proposes that the prerequisite for executing the energy recovery operation according to the multi-level conversion strategy is that the sightseeing vehicle meets the energy recovery start conditions, and the start conditions are specifically: the real-time vehicle speed is greater than the speed threshold of the corresponding level, the power of the power battery does not exceed 95%, and the brake pedal stroke reaches a preset proportion of its total stroke; the multi-level setting of the start conditions 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 the first speed; when the sightseeing vehicle is in the second level, the energy recovery start speed threshold is set to the second speed; when the sightseeing vehicle is in the third level, the energy recovery start speed threshold is set to the third speed; wherein the first speed is greater than the second speed, and the second speed is greater than the third speed.

[0044] It can be understood that the first level corresponds to the first vehicle speed set to a higher value, such as 15km / h, the second level corresponds to the second vehicle speed, set to 10km / h, and the third level corresponds to the third vehicle speed, set to 5km / h. The vehicle speed sensor continuously collects the current vehicle speed and compares it with the dynamic threshold. When the vehicle speed exceeds the threshold corresponding to the current passenger status, energy recovery is triggered. The preset proportion of the brake pedal travel is set to 30% of the travel amount. When the brake pedal is depressed beyond this proportion, it is regarded as a valid braking signal. The upper limit of the power battery power is set to 95% to avoid overcharging and resulting in a decrease in battery life.

[0045] Specifically, at the first level, the vehicle mass is relatively light and the kinetic energy during braking is relatively small. Recovery needs to be started at a higher speed to ensure sufficient energy absorption and avoid excessive braking force during low-speed recovery that affects smoothness. When the passenger capacity increases to the second level, the vehicle inertia increases, and the speed threshold is appropriately lowered to 10km / h, allowing the recovery system to capture more available energy at a lower speed. At the third level, the vehicle mass is the largest, and the kinetic energy during braking increases significantly. Lowering the speed threshold to 5km / h can start recovery in advance and make full use of the high kinetic energy brought by the large mass. By dynamically matching the speed threshold with the passenger status, frequent braking shocks caused by inefficient recovery when empty are prevented, and energy waste when fully loaded is avoided, while ensuring that the battery operates within a safe power range.

[0046] Through the above technical solutions, the energy recovery efficiency and ride comfort are effectively balanced, and the overall performance of the sightseeing bus under different passenger capacities is improved.

[0047] Furthermore, the present application proposes to construct a multi-level conversion strategy for energy recovery, which also includes a multi-level compensation mechanism for road slope: dividing the slope level into multiple levels based on the acquired road slope value, and setting the corresponding slope coefficient; setting a slope threshold, and when the slope coefficient is greater than the slope threshold, performing multi-level correction 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; using the corrected passenger capacity adjustment parameter to adjust the energy recovery intensity level.

[0048] It can be understood that the slope coefficient is quantified by the tangent value of the inclination angle collected by the inclinometer, and is used to accurately reflect the impact of the road slope on the vehicle inertia.

[0049] For example, the slope threshold is set to 0.087 (corresponding to a slope of 5 degrees), and the multi-level correction coefficient is dynamically configured based on the slope coefficient range: when the road slope coefficient is between 0.087 and 0.176 (corresponding to 5-10 degrees, tan10°≈0.176), it is determined to be a gentle slope, and the first correction coefficient of 1.2 is used. When the slope coefficient exceeds 0.176, it is determined to be a steep slope, and the second correction coefficient of 1.5 is used to correct the passenger capacity adjustment parameter. The modified parameter is input into the parameter mapping table, triggering the adjustment of the corresponding energy recovery intensity level, achieving coordinated adaptation of slope and passenger capacity. Specifically, in the slope compensation mechanism: when the road slope is detected to be 8 degrees, its corresponding slope coefficient is tan8°≈0.1405, which is determined to be a gentle slope. The system uses the first correction coefficient of 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 0.25×1.2=0.3, reaching the half-load threshold. The system automatically switches to the second intensity coefficient of 0.8 to perform energy recovery.

[0050] When a road gradient of 12 degrees is detected, the corresponding slope coefficient is tan12°≈0.2126, exceeding 0.176, indicating a steep slope. The system then applies a second correction factor of 1.5 to the passenger capacity adjustment parameter. For example, if the original passenger capacity adjustment parameter for level 2 is 0.6 and the corresponding second intensity coefficient is 0.8, the revised passenger capacity adjustment parameter becomes 0.6×1.5=0.9, exceeding the half-load threshold of 0.7. The system automatically switches to the third intensity coefficient of 1.0 to perform energy recovery.

[0051] Through the above technical solution, this application realizes graded adaptive compensation for slope driving conditions. On downhill sections, the energy recovery intensity is accurately improved through differentiated corrections for gentle slopes and steep slopes: on gentle slopes, the recovery intensity is moderately increased to utilize gravitational potential energy, and on steep slopes, the recovery intensity is increased more significantly to balance the greater inertial impact force. This not only improves the energy recovery efficiency, but also avoids the problem of excessive braking burden caused by insufficient recovery intensity on steep slopes, significantly improving driving safety. At the same time, the setting of the two-level correction coefficient enables the system to flexibly respond to road conditions of different slopes, making the multi-level conversion strategy more accurate and efficient in complex slope scenarios.

[0052] Furthermore, the present application proposes to construct a multi-stage conversion strategy for energy recovery, which also includes a multi-stage adjustment mechanism for comfort: setting the third threshold to 80% of the half-load threshold; when the passenger capacity adjustment parameter is ≥ the third threshold, limiting the maximum recovery braking torque to ≤ the first braking torque threshold, and the first braking torque threshold is determined based on the third intensity coefficient under the third level, which is 80% of the braking force corresponding to the third intensity coefficient.

[0053] It can be understood that the third threshold is set to 80% of the half-load threshold to form 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 not exceed the first braking torque threshold.

[0054] 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.

[0055] 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.

[0056] Figure 2This 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 .

[0057] Among them, 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 6 As shown, the execution module 400 includes a drive motor 410, a supercapacitor 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 supercapacitor group 420 is connected in parallel to the input end of the power battery group 430. The energy capacity of the supercapacitor group 420 is designed to be 15% of the energy capacity of the power battery group.

[0058] Specifically, the pressure sensor 110 transmits the passenger weight signal for each seat to the data fusion unit 120. After weighted summation, real-time passenger mass data is generated. This data, when compared to the rated passenger mass, serves as the passenger capacity adjustment parameter and is input into the strategy control module 300. In the status monitoring module 200, the vehicle speed sensor 210 periodically collects wheel speed pulse signals, the brake travel sensor 220 uses a linear Hall element to detect pedal displacement, and the inclinometer 230 measures the vehicle's pitch angle using a three-axis accelerometer. The strategy control module 300 matches the energy recovery intensity coefficient in the mapping table with the real-time passenger capacity adjustment parameter and calculates the target regenerative power based on the current vehicle speed and braking travel. When the target regenerative power exceeds the maximum receivable power of the power battery pack 430, control instructions prioritize energy storage in the supercapacitor pack 420. In the execution module 400, the drive motor 410 switches to generator mode under braking conditions, and the generated three-phase AC power is divided into two paths after rectification: power below 45kW is directly input into the power battery pack 430, and power above 45kW is temporarily stored in the supercapacitor group through the bidirectional DC / DC converter 440. When the system detects that the recovered power drops below 30kW, the energy stored in the supercapacitor is recharged to the power battery at a rate of 10kW / s.

[0059] As a preferred embodiment, Figure 2-6As shown, the solution of this application is specifically 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 utilizes a thin-film pressure-sensitive element. Each seat bottom is embedded with an independent sensor, connected to a data fusion unit via a parallel circuit. The data fusion unit 120 uses an accumulator to sum the multi-channel sensor signals in real time to generate real-time passenger mass. In the state monitoring module 200, the vehicle speed sensor 210 utilizes a Hall effect encoder mounted on the drive wheel shaft, the brake travel sensor 220 utilizes a linear potentiometer integrated into the brake pedal shaft, and the inclinometer 230 utilizes a triaxial accelerometer fixed to the center of the chassis longitudinal beam. In the strategy control module 300, a passenger capacity-recovery strategy mapping table is stored in an embedded controller 310 as a two-dimensional array. Its row index corresponds to the discretized interval of the passenger capacity adjustment parameter, and its column index corresponds to the combined state of vehicle speed and brake travel. Each cell stores the target recovery power value. In execution module 400, drive motor 410 utilizes a permanent magnet synchronous motor, whose inverter is connected in parallel to supercapacitor bank 420, which is composed of multiple sets of wound electric double-layer capacitors connected in series. Power battery pack 430 utilizes lithium iron phosphate battery modules and is connected to supercapacitor bank 420 via a bidirectional DC-DC converter 440. Data exchange between modules is achieved via the CAN bus, with the command output of strategy control module 300 forming a closed-loop control link with the drive motor controller, supercapacitor charge and discharge controller, and power battery management system.

[0060] Through the above technical solution, this application realizes the coordinated perception of passenger mass and driving status, adapts to the energy recovery requirements under different working conditions through multi-level energy storage media, solves the problems of low recovery efficiency and battery pulse loss caused by passenger volume fluctuations in traditional solutions, and ensures the smoothness of the braking process.

[0061] Furthermore, taking the Baizhang Waterfall Scenic Area in Wenzhou as an example, this area is characterized by many steep slopes, continuous curves, and a dense distribution of fixed stops. Sightseeing buses must complete multiple acceleration, deceleration, and stops in a short distance, and the passenger capacity fluctuates significantly with the flow of tourists. In such scenarios, traditional energy recovery technology, due to its lack of ability to predict road conditions ahead, often encounters the following problems: without prior awareness of road conditions, it often passively adjusts the recovery intensity after entering a downhill section, resulting in excessive initial speed and reliance on mechanical braking intervention, which wastes energy and increases brake pad wear. When approaching a stop, if recovery is initiated based solely on real-time vehicle speed and braking signals, it is easy to decelerate too late, causing a shock when stopping, affecting the tourist experience.

[0062] In this regard, the present application further proposes that the multi-stage conversion strategy for energy recovery also includes a scenic area route prediction mechanism: obtaining the scenic area preset route information for the sightseeing vehicle, the scenic area preset route information including the site location, road slope change points and curve distribution; obtaining the real-time position coordinates of the sightseeing vehicle in the scenic area preset route through the positioning module; based on the real-time position coordinates and the current driving direction, matching the road condition features that require deceleration within a preset distance ahead in the scenic area preset route information, the road condition features that require deceleration include adjacent sites, slope sections and turning sections; when it is predicted that there are road condition features that require deceleration ahead, the energy recovery intensity coefficient is corrected, and the corrected energy recovery intensity coefficient forms a coordinated adjustment mechanism with the passenger capacity adjustment parameter, so that the multi-stage conversion strategy adapts to the predicted braking scenario.

[0063] Specifically, the preset route information of the scenic area is imported into the strategy control module through the vehicle navigation or cloud download. The preset route information of the scenic area is stored in the form of electronic map data, which includes the latitude and longitude coordinates of each site, the location information of the road slope change point and the distribution of curves. At the same time, the algorithm built into the strategy control module parses this information into structured data to form a road condition feature database. During the operation of the sightseeing car in the scenic area, the Beidou / GPS dual-mode positioning module collects the vehicle's position coordinates in real time at a frequency of 10Hz, and combines the vehicle's driving direction information obtained by the on-board inertial measurement unit to dynamically map the vehicle's real-time position to the scenic area's 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 ahead and the starting point of the ramp, and determines the road condition characteristics within the preset distance ahead. The preset distance is usually set to 50-200 meters, and can be adaptively adjusted according to the vehicle's driving speed and passenger capacity adjustment parameters. When the system predicts that the vehicle is about to enter a deceleration zone, such as within 150 meters of a scenic spot, or 100 meters before entering a downhill section, the strategy control module activates different adjustment strategies based on the predicted road conditions: Approaching a stop: If a scenic area stop is approaching, the system adjusts parameters based on the current passenger load and the remaining distance, preemptively increasing the energy recovery coefficient to the upper limit for the corresponding passenger load. For example, at level 2, the normal energy recovery coefficient is 0.7. When the vehicle anticipates approaching a stop, the coefficient is pre-adjusted to 0.9, using the motor to recover more kinetic energy, allowing the vehicle to smoothly decelerate to a stop and reducing the need for mechanical braking.

[0064] Downhill Scenario: If the road ahead is downhill, the system first makes a secondary correction to the passenger capacity adjustment parameter based on the slope type (gentle or steep) and slope magnitude. For example, on a steep slope greater than 10°, the passenger capacity adjustment parameter is multiplied by a correction factor of 1.2. Combined with the corrected passenger capacity adjustment parameter, the energy recovery intensity coefficient is simultaneously increased. This ensures that the vehicle has sufficient braking force before entering the downhill slope, allowing for continuous energy recovery during the downhill process, avoiding frequent use of mechanical brakes due to excessive speed.

[0065] Throughout the adjustment process, the revised energy recovery intensity coefficient, along with real-time data collected from passenger capacity adjustment parameters, vehicle speed, brake pedal travel, and other parameters, contributes to the multi-stage conversion strategy. The strategy control module uses an optimization algorithm to calculate the target regenerative power in real time and sends instructions to the execution module to control the drive motor's torque generation and the energy storage path of the supercapacitor and power battery. This ensures that the energy recovery process is perfectly aligned with the vehicle's driving state and road conditions, achieving efficient and smooth regenerative control.

[0066] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A multi-stage conversion method for energy recovery of a sightseeing vehicle, characterized in that: include: Acquiring a passenger capacity adjustment parameter of the sightseeing vehicle during driving, wherein the passenger capacity adjustment parameter is calculated based on the real-time passenger capacity and the rated passenger capacity; Synchronously collect real-time driving status parameters, including real-time vehicle speed, brake pedal travel and road slope; Constructing a multi-level conversion strategy for energy recovery based on the passenger capacity adjustment parameter and the real-time driving state parameter, the multi-level conversion strategy including multi-level division of energy recovery intensity, multi-level switching of energy storage paths, and multi-level setting of start-up conditions; An energy recovery operation is performed according to the multi-stage conversion strategy.

2. The method according to claim 1, characterized in that The method of obtaining the passenger capacity adjustment parameter of the sightseeing bus includes: collecting the actual weight of each passenger through a pressure sensor, accumulating the actual weights of all passengers to obtain a real-time passenger mass, and calculating the ratio of the real-time passenger mass to the rated passenger mass to obtain the passenger capacity adjustment parameter.

3. The method according to claim 1, characterized in that The multi-level division of energy recovery intensity includes: Set the energy recovery intensity coefficient to represent the magnitude of the energy recovery braking torque. The larger the value, the greater the corresponding 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 ≤ 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 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; At the first level, the energy recovery intensity coefficient is set to a first intensity coefficient; At the second level, the energy recovery intensity coefficient is set to the second intensity coefficient; At the third level, the energy recovery intensity coefficient is set to the third intensity coefficient; The first strength coefficient is smaller than the second strength coefficient, and the second strength coefficient is smaller than the third strength coefficient.

4. The method according to claim 3, characterized in that The multi-stage switching of the energy storage path includes: determining a target regenerative power based on the regenerative energy intensity coefficient, the real-time vehicle speed, and the brake pedal travel; Setting a first power threshold and a second power threshold, where the first power threshold is the maximum instantaneous power value at which the power battery efficiently receives energy, and the second power threshold is the trigger power value at which the supercapacitor transfers energy to the power battery, and the second power threshold is less than the first power threshold; When the target recovered power is less than or equal to the first power threshold, the first-level storage path is activated: the recovered energy is directly stored in the power battery; When the target recovery power is greater than the first power threshold, the secondary storage path is activated: the supercapacitor is prioritized to absorb peak energy. When the recovery power drops below the second power threshold, the energy transfer path is activated: the energy stored in the supercapacitor is transferred to the power battery. The capacity of the supercapacitor is adapted to the pulse energy storage requirements of the sightseeing vehicle that frequently starts and stops at low speeds.

5. The method according to claim 3, characterized in that 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 speed threshold for the corresponding level, the power battery charge does not exceed 95%, and the brake pedal travel reaches a preset proportion of its total travel; The multi-level setting of the start condition is specifically the multi-level setting of the vehicle speed threshold, including When the sightseeing car is at the first level, the energy recovery starting speed threshold is set to the first speed; When the sightseeing car is at the second level, the energy recovery starting speed threshold is set to the second speed; When the sightseeing car is at the third level, the energy recovery starting speed threshold is set to the third speed; The first vehicle speed is greater than the second vehicle speed, and the second vehicle speed is greater than the third vehicle speed.

6. The method according to claim 1, characterized in that The multi-stage conversion strategy for energy recovery also includes a multi-stage compensation mechanism for road slope: Divide the road slope into multiple levels based on the obtained road slope value and set the corresponding slope coefficient; Setting a slope threshold. When the slope coefficient is greater than the slope threshold, performing a multi-level correction 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, wherein the second correction coefficient is greater than the first correction coefficient. Adjust the energy recovery intensity level using the revised passenger capacity adjustment parameters.

7. The method according to claim 3, characterized in that The multi-stage conversion strategy for energy recovery also includes a multi-stage comfort adjustment mechanism: Setting a third threshold, where the third threshold is 80% of the half-load threshold; When the passenger capacity adjustment parameter is ≥ the third threshold, the maximum recovery braking torque is limited to ≤ the first braking torque threshold, where the first braking torque threshold 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.

8. A multi-stage conversion system for energy recovery of sightseeing vehicles, characterized in that: include: The passenger parameter sensing module consists of distributed pressure sensors and a data fusion unit. The pressure sensors are independently configured on each seat of the sightseeing vehicle to collect the actual weight of each passenger. The data fusion unit is used to accumulate weight data to obtain real-time passenger mass and calculate passenger capacity adjustment parameters, providing core input for multi-level conversion. The status monitoring module is equipped with a vehicle speed sensor, a brake travel sensor, and a gradient meter to collect real-time vehicle speed, brake pedal travel, and road gradient values, providing a working condition basis for multi-level conversion; a strategy control module, comprising an embedded controller, connected to the passenger capacity parameter sensing module and the state monitoring module, the embedded controller having a built-in parameter mapping table for dynamically generating a multi-level conversion instruction for energy recovery based on received passenger capacity adjustment parameters and real-time driving state parameters, the multi-level conversion instruction including an energy recovery intensity level, a storage path level, and a start condition level; The execution module is connected to the strategy control module and includes a drive motor, a supercapacitor group and a power battery group, and is used to perform kinetic energy-electrical energy conversion and multi-level storage operations according to the multi-level conversion instructions.

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