WO2022257769A1 - Energy recovery control method and system for fully-electric aerial work platform - Google Patents

Abstract

Provided are an energy recovery control method and system for a fully-electric aerial work platform. Whether an energy recovery mode or an ordinary descent mode is employed during the descending process of a work platform (1) is determined according to the height, speed, and load of the work platform (1) and a state of the entire machine; and the descent safety and stability are controlled in real time. An energy recovery control method and system for a fully-electric shear fork-type aerial work platform solve the problems of a complicated hydraulic oil path, low overall recovery efficiency, and relatively high requirements for mounting space and costs during the energy recovery of an electro-hydraulic-drive shear fork-type aerial work platform. A lifting motor assembly is dragged in reverse by using descending potential energy, and the potential energy is converted into electric energy and stored in an energy storage battery, which achieves energy recovery. According to the technical solution of the present invention, electric energy transmission is employed, energy conversion processes are reduced, the electric energy utilization rate of the entire machine is improved, an efficient energy recycling system is combined, and recycled energy is reused, which thus improves the cruising capabilities of the entire machine, and achieves an environmentally friendly operation.

Description

An energy recovery control method and system for an all-electric aerial work platform technical field

The invention relates to the field of aerial work equipment, in particular to an energy recovery control method and system for an all-electric aerial work platform.

Background technique

Aerial work platforms are mainly used for high-altitude operations and have been widely used in modern production and life. The structure of the whole machine mainly includes lifting system, walking system, steering system and power source system. In general, during the process of lifting people or goods to a high place by the aerial work platform, the lifting system needs to be powered by the power source system to realize the lifting action. At present, the commonly used power source system is the electro-hydraulic drive system. Such a system drives the hydraulic pump to work through the motor, and realizes the purpose of hydraulic oil driving the lifting system through the control valve group. However, this type of drive system realizes the lowering of the working platform by releasing the hydraulic oil in the hydraulic system circuit and returning it to the oil tank. During this process, the gravitational potential energy of the platform is difficult to recover and reuse, resulting in low energy utilization of the whole machine system.

Chinese patent CN207819534U discloses an aerial work platform and its energy recovery device, including a driving device, a generator and a battery. Oil is used as power to drive the generator to charge the battery. The battery can be a new battery, or a battery used as the power of the aerial work platform itself, so as to realize energy recovery. The hydraulic oil drives the pump and the motor to drive the alternator to generate electricity, which is converted to DC by the conversion device and stored in the battery. This patent uses the hydraulic oil return as the power to drive the generator to charge the battery. In essence, it does not affect the descending potential energy of the working platform. Recycle. Chinese patent CN212868045U discloses a hydraulic system for an aerial work platform, including a power unit, a lifting unit, an energy storage unit, and a main hydraulic system. The energy delivery unit and the energy recovery unit are used to recover the pressure oil released by the lifting unit to the energy storage unit, and the energy recovery unit inputs the stored pressure oil into the hydraulic pump through the cut-off valve. When falling, the energy released by the hydraulic system can be recovered to the energy storage unit through the energy recovery unit, and then directly provided to the hydraulic pump through the energy delivery unit when needed, effectively reducing the waste of energy. This patent also realizes the The energy released by the hydraulic system is recovered, but the downward potential energy of the working platform is not recovered.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides an energy recovery system and control method for an all-electric aerial work platform. According to the state of the work platform, the state of the battery and the state of the vehicle, it is judged whether the energy recovery mode is selected during the descent of the work platform or the normal In the descending mode, in the energy recovery mode, the potential energy generated during the descending process of the working platform can be recovered and stored in the energy storage battery for reuse, so as to realize the long battery life and green operation of the aerial work platform.

In one aspect, the present invention provides an energy recovery control method for an all-electric aerial work platform, the steps of which include:

Step a: judge whether to enter the energy recovery mode according to the preset conditions, if yes, execute steps b, c2 and d; if not, execute step c1;

Step b: calculating the maximum torque for energy recovery;

Step c1, when the working platform enters the normal lowering mode, calculate the required torque for lowering the working platform according to the height, speed and load of the working platform, and use it as the torque to be provided by the braking device;

Step c2, when the operating platform enters the energy recovery mode, if the maximum torque of energy recovery meets the torque demand of the operating platform, the braking device will no longer provide torque; if the maximum torque of energy recovery does not meet the torque demand of the operating platform, then The difference between the torque required for the lowering of the working platform and the energy recovery torque is used as the torque to be provided by the braking device;

Step d: In the energy recovery mode, if the SOC value of the energy storage battery is higher than the preset threshold, switch to the normal down mode and perform step c1.

Optionally, the preset condition is to satisfy the following conditions at the same time:

Condition a1, the height of the working platform is higher than the preset height;

Condition a2, the current SOC value of the energy storage battery is lower than the preset threshold;

Condition a3, the energy storage battery is in a rechargeable state;

Condition a4, the whole vehicle has no fault alarm.

Optionally, the method for calculating the maximum torque of energy recovery in step b is:

Step b1, according to the height, speed and load of the working platform, calculate the required torque for the lowering of the working platform, and calculate the generating power of the driving motor based on the driving motor speed and the MAP curve;

Step b2, calculating the maximum power allowed for charging according to the current SOC value of the energy storage battery;

Step b3, using the smaller value of the power generated by the driving motor and the maximum power allowed to be charged by the energy storage battery as the energy recovery power;

Step b4, according to the energy recovery power obtained in step b3, calculate the maximum torque of energy recovery.

On the other hand, the present invention also provides an energy recovery control method and system for an all-electric aerial work platform, which includes:

A lifting electric assembly, including a drive motor, a motor controller, a servo electric cylinder and a brake device, the motor controller is connected to the drive motor, and the brake device is connected to the drive motor;

The energy storage unit includes an energy storage battery and a battery controller, the battery controller is used to detect the current SOC value, battery temperature and battery failure level of the energy storage battery, and is used to control the charge and discharge state of the energy storage battery, the battery The controller is connected to the energy storage battery;

The platform height detection device is used to detect the current height of the operation platform;

The load and inclination detection device is used to detect the current load of the working platform and the inclination angle of the whole vehicle;

An angle detection device is used to detect the angle of the scissor arm of the working platform;

A speed detection device for detecting the current speed of the work platform;

The vehicle controller is used to control the vehicle to enter the energy recovery mode or the normal descent mode; the motor controller, the battery controller, the platform height detection device, the load and inclination detection device and the speed detection The devices are respectively connected to the vehicle controller, and the vehicle controller judges the fault level of the vehicle through the state information of the platform detection device, the battery controller, and the motor controller, and according to the above preset conditions Control the whole vehicle to enter energy recovery mode or normal descent mode.

Optionally, the working platform is connected to the chassis through a scissor mechanism, the scissor mechanism includes a multi-layer scissor unit, the scissor unit includes scissor arms arranged crosswise, and the energy storage unit is arranged on the On the chassis, the lifting electric assembly is arranged between the scissor arms, the platform height detection device is arranged on the working platform, and the load and inclination detection device is arranged on the chassis, so The angle detecting device is arranged on the scissor arm, the speed detecting device is arranged on the working platform, and the vehicle controller is arranged on the chassis.

Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The energy recovery control method and system of the all-electric scissor-type aerial work platform of the present invention solves the problem of electro-hydraulic driven scissor-type aerial work in the prior art. The platform energy recovery has the problems of complex hydraulic oil circuit, low overall recovery efficiency, and relatively high demand for installation space and cost; using the descending potential energy to reverse-drag the lifting motor assembly, the potential energy is converted into electrical energy and stored in the energy storage battery. Realize energy recovery; the technical solution of the present invention adopts electric energy transmission, reduces the energy conversion process, improves the utilization rate of electric energy of the whole machine, combines the high-efficiency energy recovery system, recycles the recovered energy, and then improves the battery life of the whole machine, and achieves environmental protection Operation.

Description of drawings

Fig. 1 is a schematic structural view of an all-electric aerial work platform and an energy recovery system of the present invention;

Fig. 2 is a schematic structural view of the lifting electric assembly in the all-electric aerial work platform of the present invention;

Fig. 3 is a flow chart of the energy recovery control method of the all-electric aerial work platform of the present invention.

In the attached drawings: 1-work platform, 2-chassis, 3-lift electric assembly, 4-energy storage unit, 5-load and inclination detection device, 6-platform height detection device, 7-angle detection device, 8- Vehicle controller; 31-drive motor and motor controller, 32-servo electric cylinder, 33-braking device.

Detailed ways

The exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, which include various details of the embodiments of the present invention to facilitate understanding, and they should be considered as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

Example 1

Referring to accompanying drawing 3, the energy recovery control method of the all-electric aerial work platform of the present invention comprises the following steps:

Step a: judge whether to enter the energy recovery mode according to the preset conditions, if yes, execute steps b, c2 and d; if not, execute step c1;

Step b: calculating the maximum torque for energy recovery;

Step c1, when the working platform 1 enters the normal lowering mode, according to the height, speed and load of the working platform 1, calculate the required torque for lowering the working platform 1 as the torque to be provided by the braking device 33;

Step c2, when the working platform 1 enters the energy recovery mode, if the maximum torque of energy recovery meets the lowering torque requirement of the working platform 1, the braking device 33 no longer provides torque; if the maximum torque of energy recovery does not meet the lowering torque requirement of the working platform 1 Torque demand, the difference between the torque required for the lowering of the working platform 1 and the energy recovery torque is used as the torque to be provided by the braking device 33;

Step d: In the energy recovery mode, if the SOC value of the energy storage battery is higher than the preset threshold, switch to the normal down mode and perform step c1.

Among them, the above preconditions are that the following conditions are met at the same time:

Condition a1, the height of the working platform 1 is higher than the preset height;

Condition a2, the current SOC value of the energy storage battery is lower than the preset threshold;

Condition a3, the energy storage battery is in a rechargeable state;

Condition a4, the whole vehicle has no fault alarm.

The method for calculating the energy recovery power in the above step b is:

Step b1, according to the height, speed and load of the working platform 1, calculate the lowering demand torque of the working platform 1, and calculate the generating power of the driving motor based on the driving motor speed and the MAP curve;

specifically,

In the formula:

T _req - demand torque;

F _lift - push rod force;

V- push rod retraction speed;

n _pre - motor speed;

η - system efficiency;

Among them, the force on the push rod is:

In the formula:

m- indicates the total number of layers of the scissor arm, k indicates the kth layer, m≥k≥1;

P _m , P _k - is the vertical force acting on the joint points of each scissor arm;

θ _lift - the angle between the scissor arm and the chassis 2 plane;

α _lift - the angle between the driving rod and the chassis 2 plane;

l-the length of the scissor arm;

a- The horizontal distance between the upper hinge point of the drive rod and the connection point of the scissor arm along the axis of the scissor arm;

b- The vertical distance between the upper hinge point of the drive rod and the connection point of the scissor arm along the axis of the scissor arm;

c- The horizontal distance between the lower hinge point of the drive rod and the connection point of the scissor arm along the axis of the scissor arm;

d- the vertical distance between the lower hinge point of the drive rod and the connection point of the scissor arm along the axis of the scissor arm;

O _{k_y} - the amount of change of each connection node of the central axis, the value is as follows:

According to the descending speed of the platform, calculate the speed of the motor, and based on the speed of the driving motor and the MAP curve, look up the table to obtain the power generation of the driving motor;

Step b2, calculating the maximum power allowed for charging according to the current SOC value of the energy storage battery;

Step b3, using the smaller value of the power generated by the driving motor and the maximum power allowed to be charged by the energy storage battery as the energy recovery power;

Step b4, according to the energy recovery power obtained in step b3, calculate the maximum torque of energy recovery.

Calculation method of maximum torque for energy recovery:

T - maximum torque for energy recovery;

Pe - energy recovery power.

Example 2

Referring to accompanying drawings 1 and 2, the all-electric aerial work platform energy recovery system of the present invention includes a lifting electric assembly 3, an energy storage unit 4, a platform height detection device 6, a load and inclination detection device 5, and a speed detection device and vehicle controller 8;

in:

The lifting electric assembly 3 includes a driving motor and a motor controller 31, a servo electric cylinder 32 and a braking device 33, the motor controller is connected to the driving motor, and the braking device 33 is connected to the driving motor ;

The energy storage unit 4 includes an energy storage battery and a battery controller, the battery controller is used to detect the current SOC value, battery temperature and battery fault level of the energy storage battery, and is used to control the charge and discharge state of the energy storage battery, the a battery controller connected to the energy storage battery;

A platform height detection device 6 is used to detect the current height of the working platform 1;

The load and inclination detection device 5 is used to detect the current load of the work platform 1 and the inclination angle of the whole vehicle. The purpose of detecting the inclination angle of the whole vehicle is to detect the inclination degree of the whole vehicle. When the inclination degree of the whole vehicle is greater than a certain value, the vehicle controller 8 will determine that the vehicle safety fault alarm, the operating platform 1 needs to be lowered, but it cannot enter the energy recovery mode, it can only be in the normal lowering mode;

The angle detection device 7 is used to detect the angle of the scissor arm of the working platform 1, detect the angle of the scissor arm during the lifting and lowering process, and is used for the thrust calculation of the electric cylinder and the reference variable for the smooth rising or falling speed of the lifting system. This parameter verifies the output result of the control system;

The speed detection device is used to detect the current speed of the work platform 1 and is installed on the work platform 1;

The whole vehicle controller 8 is used to control the whole vehicle to enter the energy recovery mode or the normal descending mode; the motor controller, the battery controller, the platform height detection device 6, the load and inclination detection device 5 and the The speed detection device is respectively connected to the vehicle controller 8, and the vehicle controller 8 judges the fault level of the vehicle through the state information of the platform detection device, the battery controller, and the motor controller, and According to the preset conditions above, the whole vehicle is controlled to enter the energy recovery mode or the normal descending mode.

The working platform 1 of the all-electric aerial work platform 1 is connected to the chassis 2 through a scissors mechanism. 4 is set on the chassis 2, the lifting electric assembly 3 is set between the scissor arms, the platform height detection device 6 is set on the working platform 1, and the load and inclination detection device 5 is set on the chassis 2, the angle detection device 7 is set on the scissor arm, the speed detection device is set on the working platform 1, and the vehicle controller 8 is set on the chassis 2 .

Based on the above system structure, during the descending process of the working platform 1, when the condition a1 to a4 is satisfied at the same time, the system enters the energy recovery mode; if the whole vehicle does not meet the above conditions, the system enters the normal descent mode. In both mode and normal descent mode, the braking device 33 is required to participate. Through the above-mentioned control method, the required braking torque in different modes is calculated, thereby ensuring the safe and stable descent of the working platform 1 .

Compared with the existing technology, the energy recovery control method and system of the all-electric scissor-type aerial work platform of the above-mentioned technical solution solves the complicated hydraulic oil circuit existing in the energy recovery of the electro-hydraulic driven scissor-type aerial work platform in the prior art. 1. The overall recovery efficiency is low and the demand for installation space and cost is relatively high; the lowering potential energy is used to reverse-drag the lifting motor assembly, and the potential energy is converted into electrical energy and stored in the energy storage battery to realize energy recovery; the technical solution of the present invention The use of electric energy transmission reduces the energy conversion process and improves the utilization rate of the whole machine's electric energy. Combined with an efficient energy recovery system, the recovered energy is reused, thereby improving the battery life of the whole machine and achieving green and environmentally friendly operations.

The above specific implementation methods are not intended to limit the protection scope of the present invention. It should be apparent to those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. An energy recovery control method for an all-electric aerial work platform, characterized in that it includes the following steps:

   Step a: judge whether to enter the energy recovery mode according to the preset conditions, if yes, execute steps b, c2 and d; if not, execute step c1;

   Step b: calculating the maximum torque for energy recovery;

   Step c1, when the working platform enters the normal lowering mode, calculate the required torque for lowering the working platform according to the height, speed and load of the working platform, and use it as the torque to be provided by the braking device;

   Step c2, when the operating platform enters the energy recovery mode, if the maximum torque of energy recovery meets the torque demand of the operating platform, the braking device will no longer provide torque; if the maximum torque of energy recovery does not meet the torque demand of the operating platform, then The difference between the torque required for the lowering of the working platform and the energy recovery torque is used as the torque to be provided by the braking device;

   Step d: In the energy recovery mode, if the SOC value of the energy storage battery is higher than the preset threshold, switch to the normal down mode and perform step c1.
2. An energy recovery control method for an all-electric aerial work platform according to claim 1, wherein the preset condition is to simultaneously satisfy the following conditions:

   Condition a1, the height of the working platform is higher than the preset height;

   Condition a2, the current SOC value of the energy storage battery is lower than the preset threshold;

   Condition a3, the energy storage battery is in a rechargeable state;

   Condition a4, the whole vehicle has no fault alarm.
3. An energy recovery control method for an all-electric aerial work platform according to claim 1, wherein the method for calculating the maximum torque of energy recovery in step b is:

   Step b1, according to the height, speed and load of the working platform, calculate the required torque for the lowering of the working platform, and calculate the generating power of the driving motor based on the driving motor speed and the MAP curve;

   Step b2, calculating the maximum power allowed for charging according to the current SOC value of the energy storage battery;

   Step b3, using the smaller value of the power generated by the driving motor and the maximum power allowed to be charged by the energy storage battery as the energy recovery power;

   Step b4, according to the energy recovery power obtained in step b3, calculate the maximum torque of energy recovery.
4. An energy recovery control system for an all-electric aerial work platform, used to realize the energy recovery control method for an all-electric aerial work platform according to any one of claims 1 to 3 above, characterized in that the system includes:

   A lifting electric assembly, including a drive motor, a motor controller, a servo electric cylinder and a brake device, the motor controller is connected to the drive motor, and the brake device is connected to the drive motor;

   The energy storage unit includes an energy storage battery and a battery controller, the battery controller is used to detect the current SOC value, battery temperature and battery failure level of the energy storage battery, and is used to control the charge and discharge state of the energy storage battery, the battery The controller is connected to the energy storage battery;

   The platform height detection device is used to detect the current height of the operation platform;

   The load and inclination detection device is used to detect the current load of the working platform and the inclination angle of the whole vehicle;

   An angle detection device is used to detect the angle of the scissor arm of the working platform;

   A speed detection device for detecting the current speed of the work platform;

   The vehicle controller is used to control the vehicle to enter the energy recovery mode or the normal descent mode; the motor controller, the battery controller, the platform height detection device, the load and inclination detection device and the speed detection The devices are respectively connected to the vehicle controller, and the vehicle controller judges the fault level of the vehicle through the state information of the platform detection device, the battery controller, and the motor controller, and according to the above preset conditions Control the whole vehicle to enter energy recovery mode or normal descent mode.
5. An energy recovery control system for an all-electric aerial work platform according to claim 4, wherein the work platform is connected to the chassis through a scissor mechanism, and the scissor mechanism includes a multi-layer scissor unit, and the scissors The fork unit includes scissor arms arranged crosswise, the energy storage unit is arranged on the chassis, the lifting electric assembly is arranged between the scissor arms, and the platform height detection device is arranged on the On the work platform, the load and inclination detection device is set on the chassis, the angle detection device is set on the scissor arm, the speed detection device is set on the work platform, and the vehicle control The device is set on the chassis.

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