EP-4738695-A1 - ELECTRIC WORKING VEHICLE, ELECTRIC GARDEN OPERATION VEHICLE AND ELECTRIC RIDE-ON MOWER

EP4738695A1EP 4738695 A1EP4738695 A1EP 4738695A1EP-4738695-A1

Abstract

Provided in the embodiments of the present description are an electric working vehicle, an electric garden operation vehicle and an electric ride-on mower, which can accurately identify a sudden change in a heavy load in a timely manner and take a corresponding control measure, thereby improving the stability of a whole machine, and optimizing the application experience of a user. The electric working vehicle comprises: a functional electric motor, which has a plurality of operation parameters, and a plurality of control policies correspondingly matching the plurality of operation parameters; and a heavy-load identification unit, which is configured to select from among the plurality of operation parameters a target operation parameter which does not match the currently used first control policy for monitoring, and to determine according to the target operation parameter and/or a change situation of the target operation parameter whether the functional electric motor enters a heavy-load state. In response to determining that the functional electric motor enters the heavy-load state, a heavy-load control unit controls and adjusts the functional electric motor, such that the functional electric motor exits the heavy-load state.

Inventors

WANG, Haodong

Assignees

Jiangsu Dongcheng M&E Tools Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (20)

An electric vehicle, comprising: a motor, a collection module configured to collect at least one mechanical parameter and at least one electrical parameter of the motor, wherein the mechanical parameter comprises a rotational speed parameter, a sector time parameter, or a torque parameter, and the electrical parameter comprises a bus current parameter, a phase current parameter, a bus voltage parameter, a power parameter, a freewheeling time parameter, or a duty cycle parameter; a detection module configured to process the mechanical parameter and the electrical parameter of the motor based on a target calculation formula, and generate a target value, wherein the target calculation formula comprises at least a ratio, a slope of the ratio, or a difference of the ratio; and a determination module configured to determine whether the motor is in a heavy load state based on the target value and a predetermined target threshold, and determine, when the target value fails to meet the predetermined target threshold, that the motor is in the heavy load state, wherein the predetermined target threshold has a correspondence with the target calculation formula.
The electric vehicle according to claim 1, wherein the rotational speed parameter comprises: a rotational speed, a rotational speed difference, or a slope of a rotational speed curve; the sector time parameter comprises: a sector time, a sector time difference, or a slope of a sector time curve; the torque parameter comprises: torque, a torque difference, or a slope of a torque curve; the bus current parameter comprises: a bus current, a bus current difference, or a slope of a bus current curve; the phase current parameter comprises: a phase current, a phase current difference, or a slope of a phase current curve; the bus voltage parameter comprises: a bus voltage, a bus voltage difference, or a slope of a bus voltage curve; the power parameter comprises: power, a power difference, or a slope of a power curve; the freewheeling time parameter comprises: freewheeling time, a freewheeling time difference, or a slope of a freewheeling time curve; the duty cycle parameter comprises: a duty cycle parameter, a duty cycle parameter difference, or a slope of a duty cycle parameter curve, wherein the target value is a ratio between the mechanical parameter and the electrical parameter that have a same type.
The electric vehicle according to claim 1, wherein target calculation formula comprises: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor, wherein the target value is the ratio, and the determination module is further configured to: compare the ratio with the predetermined target threshold, and determine, when the ratio fails to meet the predetermined target threshold, that the motor is in the heavy load state.
The electric vehicle according to claim 1, wherein the target calculation formula comprises: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor, and calculating a ratio value of the ratio to a predetermined ratio, wherein the target value is the ratio value, and the determination module is further configured to: compare the ratio value with the predetermined target threshold, and determine, when the ratio value fails to meet the predetermined target threshold, that the motor is in the heavy load state.
The electric vehicle according to claim 1, wherein the target calculation formula comprises: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor, and calculating a difference of the ratio within a predetermined time period, wherein the target value is the difference, and the determination module is further configured to: compare the difference with the predetermined target threshold, and determine, when the difference fails to meet the predetermined target threshold, that the motor is in the heavy load state.
The electric vehicle according to claim 1, wherein the target calculation formula comprises: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor, and obtaining a slope of a curve of the ratio. wherein the target value is the slope, and the determination module is further configured to: compare the slope with the predetermined target threshold, and determine, when the slope fails to meet the predetermined target threshold, that the motor is in the heavy load state.
The electric vehicle according to any one of claims 3 to 6, wherein the motor comprises: a first gear, a second gear, and a third gear with progressively increasing output capacities, wherein the predetermined target threshold is the same when the motor is in the first gear, the second gear, and the third gear, or the predetermined target threshold decreases progressively when the motor is in the first gear, the second gear, and the third gear, or the predetermined target threshold increases progressively when the motor is in the first gear, the second gear, and the third gear.
The electric vehicle according to claim 7, wherein the predetermined target threshold is determined based on sampling time, and the predetermined target threshold decreases as a sampling time interval decreases, wherein the sampling time interval is a time interval for obtaining two adjacent mechanical parameters or two adjacent electrical parameters.
The electric vehicle according to claim 1, further comprising: a control module configured to adjust, in response to the motor being in the heavy load state, the mechanical parameter or electrical parameter of the motor, to reduce an operating efficiency of the motor until the motor exits the heavy load state.
A method for detecting a heavy load state applied to an electric vehicle, wherein the method comprises: collecting at least one mechanical parameter and at least one electrical parameter of the motor, wherein the mechanical parameter comprises a rotational speed parameter, a sector time parameter, or a torque parameter, and the electrical parameter comprises a bus current parameter, a phase current parameter, a bus voltage parameter, a power parameter, a freewheeling time parameter, or a duty cycle parameter; processing the mechanical parameter and the electrical parameter of the motor based on a target calculation formula, and generating a target value, wherein the target calculation formula comprising at least a ratio, a slope of the ratio, or a difference of the ratio; and determining whether the motor is in a heavy load state based on the target value and a predetermined target threshold, and determining, when the target value fails to meet the predetermined target threshold, that the motor is in the heavy load state, wherein the predetermined target threshold has a correspondence with the target calculation formula.
An electric vehicle, comprising: a frame; a functional mechanism attached to the frame, the functional mechanism comprising a functional motor and an output assembly configured to be driven by the functional motor to perform a function operation; and a controller assembly configured to control an operating state of the functional motor, wherein the functional motor has a plurality of operating parameters, and the controller assembly has a plurality of control strategies, the plurality of control strategies corresponding to the plurality of operating parameters of the functional motor, wherein the controller assembly comprises: a heavy load identification unit configured to select a target operating parameter from the plurality of operating parameters, and determine whether the functional motor enters a heavy load state based on the target operating parameter and/or a change of the target operating parameter, wherein the target operating parameter does not correspond to a first control strategy among the plurality of control strategies that is currently adopted by the controller assembly for the functional motor; and a heavy load control unit configured to select, in response to determining that the functional motor enters the heavy load state, a second control strategy from the plurality of control strategies, and control the functional motor based on the second control strategy to exit the heavy load state.
The electric vehicle according to claim 11, wherein the plurality of operating parameters of the functional motor comprise a rotational speed parameter, an electrical parameter, a power parameter, a torque parameter, and a PWM duty cycle parameter, wherein the plurality of control strategies corresponding to the plurality of operating parameters comprise a rotational speed closed-loop control strategy, a current closed-loop control strategy, a power closed-loop control strategy, a torque closed-loop control strategy, and a PWM duty cycle open-loop control strategy.
The electric vehicle according to claim 12, wherein the heavy load identification unit being configured to select a target operating parameter from the plurality of operating parameters, and determine whether the functional motor enters a heavy load state based on the target operating parameter and/or a change of the target operating parameter comprises: the heavy load identification unit being configured to select, in response to the rotational speed parameter not corresponding to the first control strategy, the rotational speed parameter as the target operating parameter, wherein the heavy load identification unit is further configured to monitor the rotational speed parameter and determine whether the functional motor enters the heavy load state based on the rotational speed parameter and/or a change of the rotational speed parameter.
The electric vehicle according to claim 13, wherein the rotational speed parameter comprises a motor rotational speed parameter, wherein the heavy load identification unit being configured to monitor the rotational speed parameter and determine whether the functional motor enters the heavy load state based on the rotational speed parameter and/or a change of the rotational speed parameter comprises: the heavy load identification unit being configured to: determine whether the motor rotational speed parameter is greater than or equal to a corresponding predetermined motor rotational speed parameter threshold during an operation of the functional motor; and determine, in response to the motor rotational speed parameter being greater than or equal to the corresponding predetermined motor rotational speed parameter threshold, that the functional motor enters the heavy load state.
The electric vehicle according to claim 14, wherein the motor rotational speed parameter comprises a motor rotational speed, a motor rotational speed difference, and a motor rotational speed change rate; wherein the motor rotational speed difference is a difference in the motor rotational speed of the functional motor between two adjacent moments; and the motor rotational speed change rate characterizes a change trend of the motor rotational speed of the functional motor at a corresponding moment; and wherein the heavy load identification unit being configured to determine whether the motor rotational speed parameter is greater than or equal to a corresponding predetermined motor rotational speed parameter threshold during an operation of the functional motor comprises the heavy load identification unit being configured to: obtain at least one motor rotational speed parameter, and determine whether the at least one motor rotational speed parameter is less than or equal to the corresponding predetermined motor rotational speed parameter threshold.
The electric vehicle according to claim 13, wherein the rotational speed parameter comprises a motor sector time parameter; and wherein the heavy load identification unit being configured to monitor the rotational speed parameter and determine whether the functional motor enters the heavy load state based on the rotational speed parameter and/or a change of the rotational speed parameter comprises the heavy load identification unit being configured to: determine whether the motor sector time parameter is greater than or equal to a corresponding predetermined motor sector time parameter threshold during an operation of the functional motor; and determine, in response to the motor sector time parameter being greater than or equal to the corresponding predetermined motor sector time parameter threshold, that the functional motor enters the heavy load state.
The electric vehicle according to claim 16, wherein the motor sector time parameter comprises motor sector time, a motor sector time difference, and a motor sector time change rate, wherein: an electrical cycle of the functional motor comprises a plurality of sectors, and the motor sector time refers to a duration of each of the plurality of sectors; the motor sector time difference is a difference between motor sector time corresponding to two adjacent moments; and the motor sector time change rate characterizes a change trend of the motor sector time; and wherein the heavy load identification unit being configured to determine whether the motor sector time parameter is greater than or equal to a corresponding predetermined motor sector time parameter threshold during an operation of the functional motor comprises: the heavy load identification unit being configured to obtain at least one motor sector time parameter and determine whether the at least one motor sector time parameter is greater than or equal to the corresponding predetermined motor sector time parameter threshold.
The electric vehicle according to claim 12, wherein the heavy load identification unit being configured to select a target operating parameter from the plurality of operating parameters, and determine whether the functional motor enters a heavy load state based on the target operating parameter and/or a change of the target operating parameter comprises: the heavy load identification unit being configured to select, in response to the electrical parameter not corresponding to the first control strategy, the electrical parameter as the target operating parameter, wherein the heavy load identification unit is further configured to monitor the electrical parameter and determine whether the functional motor enters the heavy load state based on the electrical parameter and/or a change of the electrical parameter.
The electric vehicle according to claim 18, wherein the heavy load identification unit being configured to monitor the electrical parameter and determine whether the functional motor enters the heavy load state based on the electrical parameter and/or a change of the electrical parameter comprises the heavy load identification unit being configured to: determine whether the electrical parameter is greater than or equal to a corresponding predetermined electrical parameter threshold during an operation of the functional motor; and determine, in response to the electrical parameter being greater than or equal to the corresponding predetermined electrical parameter threshold, that the functional motor enters the heavy load state.
The electric vehicle according to claim 19, wherein the electrical parameter comprises a bus current parameter, wherein the bus current parameter comprises a bus current, a bus current difference, and a bus current change rate; wherein the bus current difference is a difference in the bus current of the functional motor between two adjacent moments; and the bus current change rate characterizes a change trend of the bus current of the functional motor at a corresponding moment; and wherein the heavy load identification unit being configured to determine whether the electrical parameter is greater than or equal to a corresponding predetermined electrical parameter threshold during an operation of the functional motor comprises the heavy load identification unit being configured to: obtain at least one bus current parameter, and determine whether the at least one bus current parameter is greater than or equal to the corresponding predetermined electrical parameter threshold.

Description

FIELD The present disclosure relates to the technical field of vehicle engineering, and particularly to an electric vehicle, an electric garden vehicle, and an electric riding lawn mower. BACKGROUND Compared to traditional fuel-powered lawn mowers, battery-powered lawn mowers offer the advantages of all-weather zero emissions, zero fuel consumption, low noise, and simple maintenance due to the absence of gasoline, engine oil, air filters, spark plugs, fuel storage, etc. In battery-powered lawn mowers, an electric motor replaces the fuel engine as the power source, providing power to the drive wheel motor and the mowing motor. Battery-powered lawn mowers can independently control different drive wheel motors to achieve straight-line travel, reversing, turning, and zero-turn steering, thereby reducing the structural complexity of the entire machine and enabling more flexible control. During operation, variations in actual grass density can affect the operational load of the lawn mower. A sudden change from sparse to dense grass conditions often causes the load on the mowing motor to abruptly become a heavy load. Consequently, the output power, operating current, and other parameters of the mowing motor may increase instantaneously, potentially leading to motor damage due to overcurrent or triggering an overcurrent protection shutdown. This situation can seriously impact the overall machine stability and the user experience. SUMMARY In view of the above, embodiments of the present disclosure provide an electric work vehicle, an electric garden work vehicle, and an electric riding lawn mower, which can promptly and accurately identify sudden heavy-load conditions and take corresponding control measures, thereby enhancing overall machine stability and optimizing user experience. In an aspect, an embodiment of the present disclosure provides an electric vehicle. The electric vehicle includes: a motor, a collection module configured to collect at least one mechanical parameter and at least one electrical parameter of the motor, the mechanical parameter including a rotational speed parameter, a sector time parameter, or a torque parameter, and the electrical parameter including a bus current parameter, a phase current parameter, a bus voltage parameter, a power parameter, a freewheeling time parameter, or a duty cycle parameter; a detection module configured to process the mechanical parameter and the electrical parameter of the motor based on a target calculation formula, and generate a target value, the target calculation formula including at least a ratio, a slope of the ratio, or a difference of the ratio; and a determination module configured to determine whether the motor is in a heavy load state based on the target value and a predetermined target threshold, and determine, when the target value fails to meet the predetermined target threshold, that the motor is in the heavy load state, the predetermined target threshold having a correspondence with the target calculation formula. Optionally, the rotational speed parameter includes: a rotational speed, a rotational speed difference, or a slope of a rotational speed curve. The sector time parameter includes: a sector time, a sector time difference, or a slope of a sector time curve. The torque parameter includes: torque, a torque difference, or a slope of a torque curve. The bus current parameter includes: a bus current, a bus current difference, or a slope of a bus current curve. The phase current parameter includes: a phase current, a phase current difference, or a slope of a phase current curve. The bus voltage parameter includes: a bus voltage, a bus voltage difference, or a slope of a bus voltage curve. The power parameter includes: power, a power difference, or a slope of a power curve. The freewheeling time parameter includes: freewheeling time, a freewheeling time difference, or a slope of a freewheeling time curve. The duty cycle parameter includes: a duty cycle parameter, a duty cycle parameter difference, or a slope of a duty cycle parameter curve. The target value is a ratio between the mechanical parameter and the electrical parameter that have the same type. Optionally, the target calculation formula includes: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor. The target value is the ratio. The determination module is further configured to: compare the ratio with the predetermined target threshold, and determine, when the ratio fails to meet the predetermined target threshold, that the motor is in the heavy load state. Optionally, the target calculation formula includes: calculating a ratio between the mechanical parameter and the electrical parameter of the motor, or a ratio between different electrical parameters of the motor, and calculating a ratio value of the ratio to a predetermined ratio. The target value is the ratio value. The d