A pure electric forklift truck control system and control method

Abstract

The application discloses a kind of pure electric fork truck whole vehicle control system and control method, the whole vehicle control system includes whole vehicle controller VCU, information acquisition module, battery management system BMS, motor controller MCU1 (for controlling walking motor), motor controller MCU2 (for controlling hydraulic servo motor), solenoid valve, display screen module, GPS module, 4G / 5G communication module, network data monitoring and scheduling center.The whole vehicle control system can further achieve the purpose of energy saving, and provides real-time electric fork truck operating status for the driver, enhances driving safety, avoids the occurrence of rollover and front flip accident.

Description

Technical Field

[0001] This invention relates to the field of pure electric forklift vehicle control and intelligent communication technology, and in particular to a pure electric forklift vehicle control system and control method. Background Technology

[0002] Against the backdrop of carbon emission reduction, green intelligent manufacturing and electrification have become key directions for the transformation and upgrading of the construction machinery industry. Enterprises have successively increased their investment in electrification, launching nearly a hundred electrified products covering the entire range of construction machinery. In response to this trend, the overall technical level of forklifts is becoming increasingly sophisticated with intelligent connectivity. As the energy crisis worsens and people's environmental awareness grows, the effective development of pure electric forklifts has been promoted. Although electric forklifts can achieve zero pollution, the accident rate remains high; therefore, the intelligence of pure electric forklifts is receiving increasing attention.

[0003] Existing pure electric forklifts lack a complete vehicle controller, relying instead on a motor controller for propulsion. This results in a simple structure and limited functionality, failing to implement a range of intelligent control solutions for pure electric forklifts. This leads to high operator skill requirements and low safety. Furthermore, existing pure electric forklifts are prone to forward and side tipping during transport or turning, and there are currently no intelligent control solutions to prevent these incidents. Traditional hydraulically driven forklifts suffer from significant overflow and back pressure losses, preventing the full utilization of the electric motor and resulting in energy waste. Currently, remote dispatching of electric forklifts is limited to communication with the driver via mobile phone, without real-time monitoring of the forklift's operating status, leading to low work efficiency. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a vehicle control system and control method for a pure electric forklift. The vehicle control system can provide the driver with real-time operating status of the electric forklift, enhance driving safety, and avoid side rollover and forward rollover accidents.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A pure electric forklift vehicle control system includes a vehicle controller (VCU), a motor controller (MCU1), a motor controller (MCU2), an information acquisition module, and a solenoid valve.

[0007] The information acquisition module includes an accelerator pedal position sensor for acquiring acceleration signals of the electric forklift, a brake pedal position sensor for acquiring deceleration signals of the electric forklift, a steering wheel angle sensor for acquiring steering signals of the electric forklift, a gear sensor for acquiring gear signals of the electric forklift, a lifting handle angle sensor for acquiring fork lifting signals, a tilt handle angle sensor for acquiring fork forward / reverse tilt signals, an offset handle angle sensor for acquiring fork left / right offset signals, a fork height detection module for acquiring fork lifting height signals, and a pressure sensor for acquiring pressure inside the quantitative pump.

[0008] The vehicle controller (VCU) is connected to the lifting handle angle sensor, tilt handle angle sensor, offset handle angle sensor, accelerator pedal position sensor, brake pedal position sensor, steering wheel angle sensor, and gear position sensor via the I / O module interface to determine the driver's operating intentions. The VCU is also connected to the pressure sensor and fork height detection module via the I / O module interface to collect the electric forklift's operating information. Furthermore, the VCU is connected to the motor controllers MCU1 and MCU2 via the CAN module for data transmission, sending target speed information to both MCU1 and MCU2, and simultaneously acquiring driving parameters and fault information from the drive system.

[0009] The vehicle control unit (VCU) connects to the solenoid valve through the I / O module interface and adjusts the opening of the solenoid valve to the target opening based on the input working information.

[0010] As a preferred embodiment, the system also includes a Battery Management System (BMS), a display module, a GPS module, a 4G / 5G communication module, and a network data monitoring and dispatch center. The Vehicle Control Unit (VCU) connects to the BMS via a CAN module for data transmission, acquiring fault signals and the battery's remaining SOC (State of Charge) signal. The VCU connects to the GPS module via a UART module for communication, acquiring the electric forklift's location signal. The VCU connects to the 4G / 5G communication module via the UART module for communication, transmitting the signals collected by the VCU to the network data monitoring center and receiving information from the network data monitoring center. The VCU connects to the display module via the CAN module, displaying the information received by the VCU on the display screen.

[0011] As a preferred embodiment, the battery management system (BMS) sends information on battery temperature, remaining battery charge (SOC), charging current, and voltage to the vehicle control unit (VCU) via the CAN module, and receives control signals from the VCU.

[0012] A whole vehicle control method for a pure electric forklift, the whole vehicle control method including a rollover prevention control method, a front-overturn prevention control method and a scheduling method.

[0013] As a preferred solution, the rollover prevention control method is as follows: The vehicle control unit (VCU) calculates the maximum driving speed Vmax that ensures the pure electric forklift does not roll over according to the steering signal of the electric forklift, the pressure signal in the fixed displacement pump, and the fork lift height signal sent by the information acquisition module it receives. At the same time, the vehicle control unit (VCU) calculates the current driving speed V of the electric forklift according to the driving parameters of the drive system obtained from the motor control unit (MCU1).

[0014] Then the vehicle control unit (VCU) compares the maximum driving speed Vmax that ensures the electric forklift does not roll over with the current driving speed V of the electric forklift:

[0015] If Vmax >= V, the vehicle control unit (VCU) does not limit the vehicle speed.

[0016] If Vmax < V, the vehicle control unit (VCU) limits the maximum driving speed of the vehicle to Vmax, and sends the motor target speed signal corresponding to Vmax to the motor control unit (MCU1), and the motor control unit (MCU1) controls the walking motor speed to reach the target speed.

[0017] As a preferred solution, the front-overturn prevention control method is as follows: The vehicle control unit (VCU) receives the pressure signal in the fixed displacement pump and the fork lift height signal collected by the pressure sensor. Then the vehicle control unit (VCU) calculates the maximum height allowed for the fork to lift according to the pressure signal in the fixed displacement pump. When reaching the height critical point, the vehicle control unit (VCU) sends a danger signal to the display module through the CAN module to remind the driver to pay attention. At the same time, the speed signal and torque signal are transmitted to the motor control unit (MCU2) through the CAN module to keep the current fork height and prevent the forklift from having a front-overturn accident.

[0018] As a preferred solution, the specific dispatching method is as follows: After receiving a distress signal from the electric forklift driver, the network data monitoring and dispatching center first checks the battery remaining SOC signal and forklift location information of other electric forklifts in the work area, transmitted by the 4G / 5G communication module. Through analysis and comparison, the network data monitoring and dispatching center determines the optimal dispatching plan based on the workload and location of the task, and issues dispatching instructions to one or more electric forklifts that meet the dispatching conditions. Upon receiving the instruction, the electric forklift vehicle controller (VCU) transmits the signal to the display module via the CAN module to display and remind the driver. After the driver receives and confirms the information, the vehicle controller (VCU) sends feedback information to the network data monitoring and dispatching center. Finally, the network data monitoring and dispatching center sends the dispatched electric forklift information to the distressed electric forklift vehicle controller (VCU) via the 4G / 5G communication module. The vehicle controller (VCU) then transmits the signal to the display module via the CAN module to display and remind the driver.

[0019] Beneficial effects:

[0020] As described above, the pure electric forklift vehicle control system and control method of the present invention have the following beneficial effects:

[0021] 1) This invention adds a vehicle controller (VCU) to the original motor controller, so that intelligent control algorithms that cannot be completed on the motor controller can be implemented on the vehicle controller, which can reduce the operation requirements of the driver and improve driving safety. This invention adopts intelligent optimization algorithms to complete the speed limit control of pure electric forklifts during transportation or turning, thereby preventing forward and side rollover accidents.

[0022] 2) This invention adopts a hydraulic servo drive control scheme, eliminating the overflow valve, reducing overflow loss and back pressure loss, and reducing energy waste; it uses a 4G / 5G communication module to complete information interaction with the network data monitoring and dispatch center, which can remotely dispatch according to the workload and the status of the pure electric forklift, saving workflow and improving efficiency; in addition, the 4G / 5G communication module can also complete fault data diagnosis and uploading, remote debugging and other functions.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the vehicle control system in this invention;

[0025] Figure 2 This is a schematic diagram of signal transmission in the vehicle control system information acquisition module of the present invention;

[0026] Figure 3 This is a schematic diagram of the hydraulic servo system principle of the vehicle control system in this invention;

[0027] Figure 4 This is a schematic diagram of remote scheduling of the vehicle control system in this invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific examples and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0029] A pure electric forklift vehicle control system, such as Figure 1 As shown, the vehicle control system includes a vehicle controller (VCU), an information acquisition module, a battery management system (BMS), a motor controller (MCU1) (for controlling the drive motor), a motor controller (MCU2) (for controlling the hydraulic servo motor), solenoid valves, a display module, a GPS module, a 4G / 5G communication module, and a network data monitoring and dispatch center. The vehicle controller (VCU) includes an S32K344 chip, a VCU wake-up module, a CAN module, an I / O module, and a low-voltage control circuit module.

[0030] The vehicle controller (VCU) connects to sensors via I / O module interfaces to collect acceleration, braking, gear, and steering signals of the current electric forklift, as well as sensors to collect fork lifting, forward / reverse tilt, and left / right offset signals, thus determining the driver's operating intentions. The VCU also connects to a pressure sensor for collecting pressure within the fixed displacement pump and a fork height detection module for collecting fork height information, enabling the acquisition of the electric forklift's operational information. Furthermore, the VCU connects to motor controllers MCU1 and MCU2 via a CAN module for data transmission, sending target speed information to both MCU1 and MCU2, and simultaneously acquiring driving parameters and fault information from the drive system. The U-shaped control unit (VCU) connects to the battery management system (BMS) via the CAN module for data transmission, acquiring fault signals and battery state of charge (SOC) signals. The VCU connects to the GPS module via the UART module for communication, acquiring the electric forklift's location signal. The VCU also connects to the 4G / 5G communication module via the UART module, transmitting signals collected by the VCU to the network data monitoring center and receiving information from the center. The VCU connects to the solenoid valve via the I / O module interface, adjusting its opening to the target level. Finally, the VCU connects to the display module via the CAN module, displaying the information received by the VCU on the screen.

[0031] like Figure 2 As shown, the information acquisition module includes an accelerator pedal position sensor for acquiring acceleration signals, a brake pedal position sensor for acquiring deceleration signals, a steering wheel angle sensor for acquiring steering signals, a gear sensor for acquiring gear position signals, a lifting handle angle sensor for acquiring fork lifting signals, a tilt handle angle sensor for acquiring fork tilting signals, an offset handle angle sensor for acquiring fork left / right offset signals, a fork height detection module for acquiring fork lifting height signals, and a pressure sensor for acquiring the pressure inside the metering pump. The information acquisition module is connected to the vehicle controller (VCU) and transmits the acquired acceleration, braking, gear, steering, fork lifting, tilting, left / right offset, metering pump pressure, and fork lifting height signals to the VCU via an I / O module interface.

[0032] As a specific embodiment of the present invention, the vehicle control unit (VCU) can realize the anti-rollover function of the electric forklift:

[0033] First, the vehicle control unit (VCU) receives the steering signal of the electric forklift, the pressure signal in the metering pump, and the signal of the fork lift height sent by the information acquisition module, calculates the maximum driving speed Vmax that ensures the electric forklift does not roll over, and at the same time, the VCU calculates the current driving speed V of the electric forklift according to the driving parameters of the drive system obtained from the motor control unit (MCU1).

[0034] Next, the VCU compares the maximum driving speed Vmax at which the electric forklift does not roll over with the current driving speed V of the electric forklift:

[0035] If Vmax >= V, the VCU does not limit the vehicle speed.

[0036] If Vmax < V, the VCU limits the maximum driving speed of the vehicle to Vmax, sends the motor target speed signal corresponding to Vmax to the MCU1, and the MCU1 controls the running motor speed to reach the target speed.

[0037] As another specific embodiment of the present invention, the VCU can also implement the anti-forward roll function of the electric forklift:

[0038] The VCU receives the pressure signal in the metering pump and the fork lift height signal collected by the pressure sensor. Then, the VCU calculates the maximum height allowed for the fork to lift according to the pressure signal in the metering pump. When reaching the height critical point, the VCU sends a danger signal to the display module through the CAN module to remind the driver to pay attention, and at the same time, transmits the speed signal and torque signal to the MCU2 through the CAN module to maintain the current fork height and prevent the forklift from having a forward roll accident.

[0039] As Figure 3 shown, the VCU is connected to the information acquisition module and receives the signals collected by the information acquisition module. The VCU is connected to the MCU through the CAN module for data transmission, sends the target speed information to the MCU2, and at the same time obtains the speed information of the servo motor. The MCU2 is connected to the servo motor and controls the speed of the servo motor to reach the target speed; the VCU is connected to the solenoid valve through the interface of the I / O module and adjusts the opening degree of the solenoid valve to the target opening degree.

[0040] First, the VCU receives the fork lift / lower, front / rear tilt, left / right offset signals of the fork and the pressure signal in the metering pump sent by the information acquisition module.

[0041] Then, based on historical data, and under the premise of maximizing load capacity and motor power, the vehicle controller (VCU) generates the target speed signal of the servo motor and the target opening signal of the solenoid valve according to the current pressure signal in the fixed displacement pump and the lifting / lowering, forward / rear tilting, and left / right offset signals of the forks.

[0042] Finally, the target speed signal is sent to the motor controller MCU2. The motor controller MCU2 compares the target speed with the actual speed and then controls the servo motor to accelerate or decelerate to reach the target speed. At the same time, the vehicle controller VCU controls the opening of the solenoid valve to reach the target opening according to the target opening signal of the solenoid valve.

[0043] The GPS module acquires the electric forklift's location signal via satellite positioning and transmits the location signal to the vehicle controller (VCU) via the UART module. The 4G / 5G communication module connects to the VCU via the UART module to acquire the remaining battery power (SOC) and the electric forklift's location signal, and simultaneously connects to the network data monitoring and dispatch center for data reception and transmission.

[0044] As another specific embodiment of the present invention, the scheduling of electric forklifts can also be realized:

[0045] First, the network data monitoring and dispatch center receives a distress signal from the electric forklift driver. Then, the center checks the battery remaining SOC signal and forklift location information of other electric forklifts in other work areas, transmitted via the 4G / 5G communication module. Through analysis and comparison, the center determines the optimal dispatch plan based on the workload and location, issuing dispatch instructions to one or more electric forklifts that meet the dispatch conditions. Upon receiving the instruction, the electric forklift's vehicle controller (VCU) transmits the signal to the display module via the CAN module, displaying the information and alerting the driver. After the driver receives and confirms the information, the VCU sends feedback information to the network data monitoring and dispatch center. Finally, the network data monitoring and dispatch center sends the dispatched electric forklift information to the distressed electric forklift's VCU via the 4G / 5G communication module. The VCU then transmits the signal to the display module via the CAN module, displaying the information and alerting the driver.

[0046] For example, such as Figure 4As shown, when electric forklift 1 in area A cannot complete its work tasks within the area, the driver of electric forklift 1 sends a distress signal to the network data monitoring and dispatch center via the 4G / 5G communication module. The network data monitoring and dispatch center integrates the task load and forklift status information of areas A, B, C, and D, and sends dispatch instructions to one or more forklifts in areas B, C, and D with fewer work tasks. After receiving and confirming the information, the driver of one or more electric forklifts in areas B, C, and D sends the dispatched forklift information to the driver of electric forklift 1.

[0047] Furthermore, the battery management system (BMS) sends information from the battery temperature sensor, remaining battery charge (SOC), charging current, and voltage to the vehicle control unit (VCU) via the CAN module, and also receives control signals from the VCU.

[0048] The network data monitoring and dispatch center also receives driving parameters, fault signals, battery remaining SOC, and forklift position signals from the electric forklift drive system. It connects to the vehicle controller (VCU) via a 4G / 5G communication module. The center receives fault codes, performs data analysis and storage, and uses big data algorithms to analyze the fault codes, pinpointing the location of the vehicle control failure. It communicates with the owner and manufacturer, and uses remote terminal software to troubleshoot and eliminate vehicle control faults. Fault information and messages received from the network data monitoring and dispatch center are sent to the display module via the CAN module by the vehicle controller to alert the driver to the current operating status of the electric forklift.

[0049] This invention provides a complete control system and method for a pure electric forklift. The system collects data on the vehicle's operating conditions through the vehicle controller (VCU), optimizes the control strategy, and transmits and receives data via a 4G / 5G communication module. This enables functions such as preventing forward and side rollovers, remote monitoring, remote scheduling, and remote debugging. Furthermore, a hydraulic servo drive control scheme eliminates the need for an overflow valve, achieving energy saving and efficiency improvement.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications or equivalent substitutions made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A complete control system for a pure electric forklift, characterized in that, This includes the vehicle control unit (VCU), motor controller MCU1, motor controller MCU2, information acquisition module, and solenoid valves; The information acquisition module includes an accelerator pedal position sensor for acquiring acceleration signals of the electric forklift, a brake pedal position sensor for acquiring deceleration signals of the electric forklift, a steering wheel angle sensor for acquiring steering signals of the electric forklift, a gear sensor for acquiring gear signals of the electric forklift, a lifting handle angle sensor for acquiring fork lifting signals, a tilt handle angle sensor for acquiring fork forward / reverse tilt signals, an offset handle angle sensor for acquiring fork left / right offset signals, a fork height detection module for acquiring fork lifting height signals, and a pressure sensor for acquiring pressure inside the quantitative pump. The vehicle control unit (VCU) connects to the lift handle angle sensor, tilt handle angle sensor, offset handle angle sensor, accelerator pedal position sensor, brake pedal position sensor, steering wheel angle sensor, and gear position sensor through the I / O module interface to determine the driver's operating intentions. The vehicle controller (VCU) is connected to the pressure sensor and fork height detection module through the I / O module interface to collect the working information of the electric forklift. The VCU is also connected to the motor controllers MCU1 and MCU2 through the CAN module to transmit data, sending the target speed information to MCU1 and MCU2, and simultaneously acquiring the driving parameters and fault information of the drive system. The vehicle control unit (VCU) connects to the solenoid valve through the I / O module interface and adjusts the opening of the solenoid valve to the target opening based on the input working information. It also includes a battery management system (BMS), a display module, a GPS module, a 4G / 5G communication module, and a network data monitoring and dispatch center. The vehicle controller (VCU) connects to the BMS via the CAN module and transmits data to obtain fault signals and the battery's remaining SOC signal. The VCU connects to the GPS module via the UART module and communicates to obtain the electric forklift's position signal. The vehicle controller (VCU) connects and communicates with the 4G / 5G communication module via the UART module. The VCU transmits signals collected by the VCU to the network data monitoring center via the 4G / 5G communication module and receives information sent by the network data monitoring center. The VCU connects to the display module via the CAN module, displaying the information received by the VCU on the display screen. The battery management system (BMS) sends information on battery temperature, remaining battery charge (SOC), charging current, and voltage to the VCU via the CAN module and receives control signals from the VCU. After the network data monitoring and dispatching center receives the distress signal from the electric forklift driver, the network data monitoring and dispatching center first checks the remaining battery power SOC signal and the forklift position information of the electric forklifts in other working areas sent by the 4G / 5G communication module. Through analysis and comparison, the network data monitoring and dispatching center obtains the best dispatching plan based on the task volume and task location, and issues a dispatching instruction to one or more electric forklifts that meet the dispatching conditions. The vehicle control unit VCU of the electric forklift that receives the instruction transmits the signal to the display module through the CAN module to display and remind the driver. After the driver receives and confirms the information, the vehicle control unit VCU sends the feedback information to the network data monitoring and dispatching center. Finally, the network data monitoring and dispatching center sends the information of the electric forklifts receiving the dispatch to the vehicle control unit VCU of the distressed electric forklift through the 4G / 5G communication module. The vehicle control unit VCU transmits the signal to the display module through the CAN module to display and remind the driver.

2. A method for controlling a pure electric forklift, characterized in that, Applied to the vehicle control system described in claim 1, the vehicle control method includes an anti-rollover control method, an anti-front-rollover control method, and a dispatching method.

3. The method for controlling a pure electric forklift according to claim 2, characterized in that, The anti-rollover control method is as follows: The vehicle control unit VCU calculates the maximum driving speed Vmax that ensures the electric forklift does not roll over based on the steering signal, the pressure signal in the fixed displacement pump, and the fork lift height signal of the electric forklift sent by the information acquisition module it receives. At the same time, the vehicle control unit VCU calculates the current driving speed V of the electric forklift based on the driving parameters of the drive system obtained from the motor controller MCU1. Then the vehicle control unit VCU compares the maximum driving speed Vmax that ensures the electric forklift does not roll over with the current driving speed V of the electric forklift: If Vmax >= V, the vehicle control unit VCU does not limit the vehicle speed. If Vmax < V, the vehicle control unit VCU limits the maximum driving speed of the vehicle to Vmax, and sends the motor target speed signal corresponding to Vmax to the motor controller MCU1, and the motor controller MCU1 controls the walking motor speed to reach the target speed.

4. The method for controlling a pure electric forklift according to claim 2, characterized in that, The anti-front-rollover control method is as follows: The vehicle control unit VCU receives the pressure signal in the fixed displacement pump and the fork lift height signal collected by the pressure sensor. Then the vehicle control unit VCU calculates the maximum height allowed for the fork to lift based on the pressure signal in the fixed displacement pump. When reaching the height critical point, the vehicle control unit VCU sends a danger signal to the display module through the CAN module to remind the driver to pay attention. At the same time, the speed signal and torque signal are transmitted to the motor controller MCU2 through the CAN module to maintain the current fork height and prevent the forklift from having a front-rollover accident.

5. The method for controlling a pure electric forklift according to claim 2, characterized in that, The dispatching method is as follows: After receiving a distress signal from an electric forklift driver, the network data monitoring and dispatch center first checks the battery remaining SOC signal and forklift location information of other electric forklifts in other work areas, transmitted via the 4G / 5G communication module. Through analysis and comparison, the network data monitoring and dispatch center determines the optimal dispatching plan based on the workload and location of the task, and issues dispatching instructions to one or more electric forklifts that meet the dispatching conditions. Upon receiving the instruction, the electric forklift's vehicle controller (VCU) transmits the signal to the display module via the CAN module to display and remind the driver. After the driver receives and confirms the information, the vehicle controller (VCU) sends feedback information to the network data monitoring and dispatch center. Finally, the network data monitoring and dispatch center sends the dispatched electric forklift information to the distressed electric forklift's vehicle controller (VCU) via the 4G / 5G communication module. The vehicle controller (VCU) then transmits the signal to the display module via the CAN module to display and remind the driver.

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