CN111469856A - Forklift and speed control method for forklift - Google Patents

Forklift and speed control method for forklift Download PDF

Info

Publication number
CN111469856A
CN111469856A CN202010306459.XA CN202010306459A CN111469856A CN 111469856 A CN111469856 A CN 111469856A CN 202010306459 A CN202010306459 A CN 202010306459A CN 111469856 A CN111469856 A CN 111469856A
Authority
CN
China
Prior art keywords
speed
forklift
absolute value
change slope
slope
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010306459.XA
Other languages
Chinese (zh)
Other versions
CN111469856B (en
Inventor
廖钢强
但汉兵
谢燕朋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hunan Sany Intelligent Control Equipment Co Ltd
Original Assignee
Hunan Sanyi Electric Control Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hunan Sanyi Electric Control Technology Co ltd filed Critical Hunan Sanyi Electric Control Technology Co ltd
Priority to CN202010306459.XA priority Critical patent/CN111469856B/en
Publication of CN111469856A publication Critical patent/CN111469856A/en
Application granted granted Critical
Publication of CN111469856B publication Critical patent/CN111469856B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
    • B60W40/105—Speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/07572—Propulsion arrangements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2300/00—Indexing codes relating to the type of vehicle
    • B60W2300/12—Trucks; Load vehicles
    • B60W2300/121—Fork lift trucks, Clarks

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Mathematical Physics (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Civil Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Abstract

The invention provides a forklift and a speed control method of the forklift. The speed control method of the forklift comprises the following steps: and in the process that the running speed of the forklift changes from the current running speed to the target running speed, controlling the reference speed according to the difference between the actual speed and the reference speed of the forklift. The invention can reduce or avoid the tracking error between the actual speed and the reference speed of the forklift and improve the poor driving experience of the forklift in the acceleration or deceleration process.

Description

Forklift and speed control method for forklift
Technical Field
The invention relates to the technical field of vehicle engineering, in particular to a forklift and a speed control method of the forklift.
Background
The forklift is provided with an accelerator pedal and a brake pedal, the acceleration of the forklift can be controlled through the accelerator pedal, and the deceleration and braking of the forklift can be controlled through the brake pedal. Since the road condition and the load of the forklift are different, there is a possibility that the actual speed of the forklift cannot reach the target speed in the actual acceleration or deceleration process of the forklift.
In order to enable the actual speed and the target speed of the forklift to be matched with each other, one of solutions in the related art is: and controlling the forklift to adjust the speed at a certain fixed slope, assigning the actual speed to the real-time reference speed when the actual speed is between the real-time reference speed and the final target speed, and controlling the reference speed to keep changing when the actual speed is below the real-time reference speed. The reference speed refers to a speed reference value calculated in real time by adopting a linear function when speed adjustment is performed with a certain slope.
However, the related art has a disadvantage that a tracking error between the actual speed and the reference speed is always present, resulting in poor driving experience of the forklift during acceleration or deceleration.
Disclosure of Invention
The present invention is directed to solving or improving at least one of the above technical problems.
Therefore, a first object of the present invention is to provide a method for controlling the speed of a forklift.
A second object of the present invention is to provide a forklift.
To achieve the first object of the present invention, an embodiment of the present invention provides a speed control method of a forklift, including: and in the process that the running speed of the forklift changes from the current running speed to the target running speed, controlling the reference speed according to the difference between the actual speed and the reference speed of the forklift.
The present embodiment aims to adjust the reference speed so that the actual speed and the reference speed can track and match each other. Compare in the correlation technique with reference speed limit at certain numerical value or scope, this embodiment is initiatively adjusted reference speed to plan fork truck's the speed of traveling better, thereby improve fork truck and drive experience.
In addition, the technical solution provided by the above embodiment of the present invention may further have the following additional technical features:
among the above-mentioned technical scheme, according to the difference of fork truck's actual speed and reference speed, control reference speed specifically includes: judging that the difference is less than or equal to a first difference threshold value, and controlling the reference speed to be reduced; or judging that the difference is larger than the first difference threshold value and smaller than or equal to the second difference threshold value, and controlling the reference speed to be kept unchanged; or judging that the difference is larger than the second difference threshold and smaller than or equal to the third difference threshold, and controlling the reference speed to rise.
There is often a static difference between the actual speed and the reference speed. The embodiment can implement a reasonable speed planning or control scheme for the forklift according to the difference degree of the static difference between the actual speed and the reference speed.
In any of the above technical solutions, after the step of controlling the reference speed according to the difference between the actual speed of the forklift and the reference speed is performed, the method for controlling the speed of the forklift further includes: judging that the reference speed is greater than the accelerator speed of the forklift, and reducing the reference speed to the accelerator speed; or judging that the reference speed is less than or equal to the accelerator speed of the forklift, and keeping the reference speed unchanged.
This embodiment can be according to throttle speed, and rationally adjust reference speed to plan fork truck's the rate of travel better, thereby improve fork truck and drive and experience.
Among any one of the above-mentioned technical scheme, according to the difference of fork truck's actual speed and reference speed, specifically include controlling reference speed: and at least two speed change slopes are adopted to linearly adjust the reference speed.
In the embodiment, the reference speed is linearly adjusted through the speed change slope changed in a segmented manner, so that the change of the reference speed is softer, and the sudden rising or falling of the speed is avoided, so that the driving experience is improved.
In any of the above technical solutions, the linear adjustment of the reference speed using at least two speed change slopes specifically includes: adjusting the reference speed from zero speed to low-speed inching threshold speed by adopting a first speed change slope; adjusting the reference speed from the low-speed inching threshold speed to an inflection point speed by adopting a second speed change slope; adjusting the reference speed from the knee point speed to the maximum speed by adopting a third speed change slope; wherein the absolute value of the first speed change slope is less than or equal to the absolute value of the second speed change slope, and the absolute value of the third speed change slope is less than the absolute value of the second speed change slope.
This embodiment also can guarantee fork truck to the regulation efficiency of reference speed on the basis of guaranteeing to drive experience.
In any of the above technical solutions, when the accelerator speed of the forklift is less than or equal to the low-speed inching threshold speed, the absolute value of the first speed change slope is less than the absolute value of the second speed change slope; when the accelerator speed of the forklift is greater than the low-speed inching threshold speed, the absolute value of the change slope of the first speed is equal to the absolute value of the change slope of the second speed.
This embodiment also can guarantee fork truck to the regulation efficiency of reference speed on the basis of guaranteeing to drive experience.
In any of the above technical solutions, the absolute value of the third speed change slope is adjusted according to the torque change trend of the driving motor of the forklift; and if the torque variation trend of the driving motor is judged to be increased, the absolute value of the third speed variation slope is increased, and if the torque variation trend of the driving motor is judged to be decreased, the absolute value of the third speed variation slope is decreased.
The embodiment feeds back the torque variation trend of the driving motor to the speed plan for the forklift, so that the speed variation slope adopted in the speed plan control of the forklift can automatically adapt to the motor control system.
In any of the above technical solutions, the linear adjustment of the reference speed using at least two speed change slopes specifically includes: adjusting the reference speed from the maximum speed to the inflection point speed by adopting a fourth speed change slope; adjusting the reference speed from the knee point speed to a low-speed inching threshold speed by adopting a fifth speed change slope; adjusting the reference speed from the low-speed inching threshold speed to a zero speed by adopting a sixth speed change slope; wherein, the absolute value of the fourth speed change slope is less than or equal to the absolute value of the fifth speed change slope, and the absolute value of the sixth speed change slope is less than the absolute value of the fifth speed change slope.
This embodiment also can guarantee fork truck to the regulation efficiency of reference speed on the basis of guaranteeing to drive experience.
In any of the above technical solutions, when the accelerator speed of the forklift is less than or equal to the low-speed inching threshold speed, setting the absolute value of the sixth speed change slope to be less than the absolute value of the fifth speed change slope; when the accelerator speed of the forklift is greater than the low-speed inching threshold speed, setting the absolute value of the sixth speed change slope equal to the absolute value of the fifth speed change slope; and adjusting the absolute value of the fourth speed change slope according to the moment change trend of the driving motor of the forklift, increasing the absolute value of the fourth speed change slope when the moment change trend of the driving motor is judged to be increased, and decreasing the absolute value of the fourth speed change slope when the moment change trend of the driving motor is judged to be decreased.
This embodiment also can guarantee fork truck to the regulation efficiency of reference speed on the basis of guaranteeing to drive experience. The embodiment feeds back the torque variation trend of the driving motor to the speed plan for the forklift, so that the speed variation slope adopted in the speed plan control of the forklift can automatically adapt to the motor control system.
To achieve the second object of the present invention, embodiments of the present invention provide a forklift truck, which implements the steps of the speed control method of the forklift truck according to any one of the embodiments of the present invention.
The forklift truck according to the embodiment of the present invention implements the steps of the method for controlling the speed of the forklift truck according to any embodiment of the present invention, and therefore, the method for controlling the speed of the forklift truck according to any embodiment of the present invention has all the advantages of the method for controlling the speed of the forklift truck according to any embodiment of the present invention, and details thereof are not described herein.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a flow chart of a first step of a method for controlling the speed of a forklift according to some embodiments of the present invention;
FIG. 2 is a schematic diagram of the difference between the actual speed and the reference speed in some embodiments of the present invention;
FIG. 3 is a flow chart of a second step of a method of controlling the speed of a forklift according to some embodiments of the present invention;
FIG. 4 is a flow chart of steps for determining a slope of a speed change in accordance with some embodiments of the present invention;
FIG. 5 is a flow chart of a third step of a method of controlling the speed of a forklift according to some embodiments of the present invention;
FIG. 6 is a schematic diagram of a reference speed profile for some embodiments of the present invention.
Wherein, the corresponding relation between the reference signs and the component names is as follows:
L1first curve, L2Second curve, L3Third curve, L4: actual speed profile.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
A forklift and a speed control method of the forklift according to some embodiments of the present invention will be described below with reference to fig. 1 to 6.
Example 1:
as shown in fig. 1, the present embodiment provides a speed control method for a forklift, including:
step S102, at the running speed v of the forkliftOperation ofFrom the current running speed vCurrent operationChange to target operating speed vTarget operationAccording to the actual speed v of the forkliftPractice ofWith reference speed vReference toDifference of (2)Iso vPractice of-vReference toFor reference velocity vReference toAnd (5) controlling.
Before the forklift starts, an appropriate speed mode needs to be selected according to the load condition of the forklift, namely: the maximum speed of the full throttle in the forklift operating mode is selected. The speed variable values in different operation modes are different, and can be set by a user in a self-defining way.
In this embodiment, the advancing process of the forklift is controlled by an accelerator pedal and a brake pedal. Wherein the running speed v of the forklift truckOperation ofFrom the current running speed vCurrent operationChange to target operating speed vTarget operationThe speed-increasing process of the forklift changing from low speed to high speed or the speed-reducing process of the forklift changing from high speed to low speed is referred to. Actual speed v of forkliftPractice ofRefers to the actual operating speed of the forklift during operation. Reference speed v of a fork-lift truckReference toThe reference value of the forklift speed is calculated in real time by adopting a function. Actual speed v of forkliftPractice ofWith reference speed vReference toDifference v ofPractice of-vReference toRefers to the actual velocity vPractice ofWith reference speed vReference toIs determined by the difference of (1).
The purpose of this embodiment is to align the reference velocity vReference toAdjustment is made so that the actual speed vPractice ofAnd a reference velocity vReference toCan track and match each other. Compared to a reference velocity vReference toRelated art limited to a certain value or range, the present embodiment actively couples the reference velocity vReference toThe adjustment is carried out to plan the traveling speed of the forklift better, and therefore the driving experience of the forklift is improved.
Example 2:
the present embodiment provides a speed control method of a forklift, and in addition to the technical features of embodiment 1 described above, the present embodiment further includes the following technical features.
According to the actual speed v of the forkliftPractice ofWith reference speed vReference toFor a reference velocity vReference toThe control specifically comprises: determinationDifference vPractice of-vReference toLess than or equal to a first difference threshold, controlling the reference speed vReference toDecrease; or to determine a difference vPractice of-vReference toGreater than a first difference threshold and less than or equal to a second difference threshold, controlling the reference speed vReference toKeeping the original shape; or to determine a difference vPractice of-vReference toGreater than the second difference threshold and less than or equal to a third difference threshold, controlling the reference speed vReference toAnd (4) rising.
Actual velocity vPractice ofAnd a reference velocity vReference toThere is often a static difference between them. The purpose of this embodiment is to depend on the actual speed vPractice ofAnd a reference velocity vReference toThe difference degree of the static difference between the two parts can implement reasonable speed planning or control scheme for the forklift. Wherein when the actual speed vPractice ofAnd a reference velocity vReference toWhen there is a static difference between the two, the processing manner for the acceleration process and the reduction process is the same, and the processing manner for the acceleration process is exemplified below.
During acceleration, when the difference v isPractice of-vReference toLess than or equal to the first difference threshold, then the actual speed profile L4Third curve L in FIG. 23In this case, the reference speed v needs to be loweredReference toSo that the actual speed vPractice ofCapable of tracking a reference velocity vReference to. When the difference v isPractice of-vReference toGreater than the first difference threshold and less than or equal to the second difference threshold, the actual speed profile L4Third curve L in FIG. 23And a second curve L2When the reference speed v is controlledReference toIs maintained constant so that the actual speed vPractice ofCapable of tracking an upper reference velocity vReference to. When the difference v is as shown in FIG. 2Practice of-vReference toGreater than the second difference threshold and less than or equal to the third difference threshold, the actual speed profile L4At a first curve L1And a second curve L2When the reference speed v is controlledReference toAnd (4) rising. Wherein the first difference threshold, the second difference threshold and the third difference threshold can be determined by one skilled in the artAnd selecting and adjusting according to actual needs.
In other words, when the actual velocity v isPractice ofAnd a reference velocity vReference toHave the following relations respectively, then the reference speed v is respectively adopted in the following different waysReference toHandling or controlling differently: determination of the actual speed vPractice ofNo more than reference speed vReference toX, then the reference speed v is reducedReference to(ii) a Determination of reference velocity vReference to-X<Actual velocity vPractice ofNo more than reference speed vReference toX/2, such that the reference velocity v is obtainedReference toKeeping the original shape; determination of reference velocity vReference to-X/2<Actual velocity vPractice ofNo more than reference speed vReference to+ X/2, the reference speed v is controlledReference toAnd (4) rising. Wherein, the value of X can be selected or adjusted by the technicians in the field according to the actual needs.
Example 3:
the present embodiment provides a speed control method for a forklift, and in addition to the technical features of any one of the above embodiments, the present embodiment further includes the following technical features.
In the implementation according to the actual speed v of the forkliftPractice ofWith reference speed vReference toDifference v ofPractice of-vReference toFor reference velocity vReference toAfter the control, the speed control method of the forklift further comprises the following steps: determination of reference velocity vReference toGreater than the throttle speed v of a fork-lift truckThrottle valveWill refer to the velocity vReference toDown to throttle speed vThrottle valve(ii) a Or determining the reference velocity vReference toLess than or equal to the throttle speed v of the fork-lift truckThrottle valveWill refer to the velocity vReference toAnd maintained unchanged.
The purpose of the embodiment is to depend on the throttle speed vThrottle valveFor a reference velocity vReference toReasonably adjust to plan the driving speed of the forklift better, thereby improving the driving experience of the forklift.
Example 4:
the present embodiment provides a speed control method for a forklift, and in addition to the technical features of any one of the above embodiments, the present embodiment further includes the following technical features.
According to the actual speed v of the forkliftPractice ofWith reference speed vReference toDifference v ofPractice of-vReference toFor reference velocity vReference toThe control specifically comprises: using at least two slopes of speed variation, versus a reference speed vReference toA linear adjustment is performed.
In particular, two different speed variation slopes may be used in a two-step manner for the reference speed vReference toThe regulation control can also adopt three or more different speed change slopes to carry out regulation control on the reference speed v in a three-stage or multi-stage modeReference toAnd (5) performing adjustment control. The object of this embodiment is that the speed change slope, which changes in stages, is related to the reference speed vReference toLinear regulation is carried out so that the reference speed vReference toThe change of the speed is softer, and the sudden rising or falling of the speed is avoided, so that the driving experience is improved.
Alternatively, the reference speed v is set by the present embodimentReference toAfter the linear adjustment is performed, the reference velocity v is further determined by the procedure of example 3Reference toAnd throttle speed vThrottle valveThe magnitude relationship of (1). Wherein the reference speed v is determinedReference toGreater than the throttle speed v of a fork-lift truckThrottle valveWill refer to the velocity vReference toDown to throttle speed vThrottle valve. Determination of reference velocity vReference toLess than or equal to the throttle speed v of the fork-lift truckThrottle valveWill refer to the velocity vReference toAnd maintained unchanged.
Example 5:
as shown in fig. 3, the present embodiment provides a speed control method of a forklift, and in addition to the technical features of embodiment 4 described above, the present embodiment further includes the following technical features.
Using at least two slopes of speed variation, versus a reference speed vReference toThe linear adjustment specifically includes:
step S302, adopting a first speed change slope A1Will refer to the velocity vReference toFrom zero speedThe velocity is adjusted to a low-speed inching threshold velocity vThreshold value；
Step S304, adopting a second speed change slope A2Will refer to the velocity vReference toFrom low-speed jogging threshold speed vThreshold valueAdjusted to knee velocity vInflection point；
Step S306, adopting a third speed change slope A3Will refer to the velocity vReference toVelocity v of inflection pointInflection pointAdjusted to maximum velocity vMaximum of；
Wherein the first speed change slope A1Is less than or equal to the second speed change slope A2Absolute value of (a) third speed change slope A3Is smaller than the second speed change slope A2Absolute value of (a).
When it is desired to increase the reference velocity vReference toIn this embodiment, the reference velocity v is obtained by the above stepsReference toAcceleration is performed. Reference velocity vReference toThe variation curve of (2) is shown in fig. 6.
Specifically, the solid line in fig. 6 is a reference speed increasing curve, and the broken line in fig. 6 is a reference speed decreasing curve. First, in the range of 0 to T1Or 0 to T1In the time range of' the first speed change slope A is adopted1Will refer to the velocity vReference toRegulating from zero speed to low speed inching threshold speed vThreshold value. Further, at T1To T3Or T1' to T3In the time range of' the second speed change slope A is adopted2Will refer to the velocity vReference toFrom low-speed jogging threshold speed vThreshold valueAdjusted to knee velocity vInflection point. Finally, at T3To T4Or T3' to T4In the time range of' the third speed change slope A is adopted3Will refer to the velocity vReference toVelocity v of inflection pointInflection pointAdjusted to maximum velocity vMaximum of。
This embodiment not only aligns the reference velocity v in stagesReference toAnd performing linear adjustment. And, the slope A changes due to the second speed2Relatively large, therefore, the essenceOn the basis of ensuring the driving experience, the embodiment can also ensure the reference speed v of the forkliftReference toThe efficiency of the regulation of.
Example 6:
the present embodiment provides a speed control method of a forklift, and in addition to the technical features of embodiment 5 described above, the present embodiment further includes the following technical features.
When the throttle speed v of the forklift truckThrottle valveLess than or equal to low-speed jogging threshold speed vThreshold valueFirst rate of change slope A1Is smaller than the second speed change slope A2Absolute value of (d); when the throttle speed v of the forklift truckThrottle valveGreater than the low-speed inching threshold speed vThreshold valueFirst rate of change slope A1Is equal to the second speed change slope a2Absolute value of (a).
In other words, the present embodiment varies the accelerator speed vThrottle valveAnd a low speed inching threshold speed vThreshold valueComparing, and determining the first speed change slope A according to the relationship between the two1The size of (2).
Specifically, referring to fig. 4, the present embodiment determines the reference speed v of the forklift by the following stepsReference toSpeed change slope of (2):
step S402, determining a reference speed vReference toWith low-speed inching threshold speed vThreshold valueThe magnitude relationship of (1);
wherein the judgment result is a reference speed vReference toLess than or equal to low-speed jogging threshold speed vThreshold valueThen, step S404 is executed to determine the reference speed vReference toGreater than the low-speed inching threshold speed vThreshold valueThen, go to step S406;
step S404, determining the accelerator speed vThrottle valveWith low-speed inching threshold speed vThreshold valueThe magnitude relationship of (1);
wherein the judgment result is the accelerator speed vThrottle valveLess than or equal to low-speed jogging threshold speed vThreshold valueThen, step S408 is executed, and the result of determination is the accelerator speed vThrottle valveGreater than the low-speed inching threshold speed vThreshold valueThen, go to step S410;
step S406, determining the reference speed vReference toVelocity v at the inflection pointInflection pointThe magnitude relationship of (1);
wherein the judgment result is a reference speed vReference toVelocity v less than or equal to the knee pointInflection pointThen step S412 is executed to determine the reference speed vReference toVelocity v greater than inflection pointInflection pointThen go to step S414;
step S408, adopting the speed change slope of the jogging region as a first speed change slope A1；
After step S408 is executed, step S416 is executed;
step S410, using the velocity change slope in the inflection point outside the jogging region as the first velocity change slope A1；
After step S410 is executed, step S416 is executed;
step S412, using the change slope of the velocity in the inflection point outside the jogging region as the second change slope A of the velocity2；
After step S412 is executed, step S416 is executed;
step S414, using the speed change slope after the inflection point as the third speed change slope A3；
After step S416 is executed, step S416 is executed;
step S416, determining the reference speed vReference toWith throttle speed vThrottle valveThe magnitude relationship of (1);
wherein the judgment result is a reference speed vReference toGreater than the throttle speed v of a fork-lift truckThrottle valveIn step S418, the reference speed v is determined as a result of the determinationReference toLess than or equal to the throttle speed v of the fork-lift truckThrottle valveWill refer to the velocity vReference toKeeping the operation unchanged and finishing the operation;
step S418. referring to the speed vReference toIs set to be equal to the throttle speed vThrottle valveAnd equals, and ends the operation.
In this embodiment, the micro-motion region velocity change slope and the post-inflection-point velocity change slope are respectively smaller than the intra-inflection-point velocity change slope outside the micro-motion region.
Example 7:
the present embodiment provides a speed control method for a forklift, and in addition to the technical features of any one of the above embodiments, the present embodiment further includes the following technical features.
According to the moment variation trend Delta T of the driving motor of the forklifteFor the third speed change slope A3Adjusting the absolute value of the absolute value; wherein, the moment variation trend Delta T of the driving motor is judgedeIncreasing, then increasing the third speed change slope A3Determining the torque variation trend Delta T of the driving motoreDecreasing, then decreasing the third speed change slope A3Absolute value of (a).
With a third speed variation slope A3For reference velocity vReference toDuring the adjustment, i.e. the reference speed vReference toChange to velocity v over inflection pointInflection pointThen, the constant power section is entered. In this interval, the present embodiment changes the slope a at the initially set third speed3On the basis of the moment, the variation trend of the moment of the output of the driving motor of the forklift is judged, and the moment variation trend delta T of the driving motor is obtainedeAdjusting the third speed variation slope A3。
For example, an ac motor may be used to vector control the speed of travel of the truck, at which time the drive motor torque TeThe following relationship is provided between the d-axis reference current and the q-axis reference current:
Te＝k×id×iq；
where k is a constant coefficient associated with the motor, idIs d-axis reference current, i, of the motorqFor the q-axis reference current of the motor, the change of the product of all d-axis reference current and q-axis reference current reflects the moment variation trend Delta T of the driving motore. The d-axis reference current is obtained by a flux weakening control current distribution algorithm.
Wherein, the torque variation trend Delta T of the driving motore＝Te(k)-Te(k-1). When the torque of the driving motor changesTrend Delta TeIf the third speed change slope is larger than zero, the third speed change slope A is increased3Absolute value of (1), torque variation tendency Δ T of the drive motoreLess than zero, the third speed change slope A is reduced3Absolute value of (a).
The embodiment feeds back the torque variation trend of the driving motor to the speed plan for the forklift, so that the speed variation slope adopted in the speed plan control of the forklift can automatically adapt to the motor control system.
Example 8:
as shown in fig. 5, the present embodiment provides a speed control method of a forklift, and in addition to the technical features of any one of the above embodiments, the present embodiment further includes the following technical features.
Using at least two slopes of speed variation, versus a reference speed vReference toThe linear adjustment specifically includes:
step S502, adopting a fourth speed change slope A4Will refer to the velocity vReference toFrom the maximum velocity vMaximum ofAdjusted to knee velocity vInflection point；
Step S504, a fifth speed change slope A is adopted5Will refer to the velocity vReference toVelocity v of inflection pointInflection pointAdjusting to low-speed inching threshold speed vThreshold value；
Step S506, adopting a sixth speed change slope A6Will refer to the velocity vReference toFrom low-speed jogging threshold speed vThreshold valueAdjusting to zero speed;
wherein the fourth speed change slope A4Is less than or equal to the fifth speed change slope A5Absolute value of (a), sixth speed change slope A6Is less than the fifth speed change slope a5Absolute value of (a).
Specifically, the solid line in fig. 6 is a reference speed increasing curve, and the broken line in fig. 6 is a reference speed decreasing curve. First, at T1To T2Or T1' to T2In the time range of' the fourth speed change slope A is adopted4Will refer to the velocity vReference toFrom the maximum velocity vMaximum ofAdjusted to knee velocity vInflection point. Further, at T2To T4Or T2' to T4In the time range of' the fifth speed change slope A is used5Will refer to the velocity vReference toVelocity v of inflection pointInflection pointAdjusting to low-speed inching threshold speed vThreshold value. Finally, at T4To T5Or T4' to T5In the time range of' the sixth speed change slope A is used6Will refer to the velocity vReference toFrom low-speed jogging threshold speed vThreshold valueAdjust to zero speed.
This embodiment not only aligns the reference velocity v in stagesReference toAnd performing linear adjustment. And, the slope A due to the fifth speed change5Relatively big, therefore, this embodiment also can guarantee fork truck to reference speed v on the basis of guaranteeing to drive to experienceReference toThe efficiency of the regulation of.
Example 9:
the present embodiment provides a speed control method of a forklift, and in addition to the technical features of the above embodiments, the present embodiment further includes the following technical features.
When the throttle speed v of the forklift truckThrottle valveLess than or equal to low-speed jogging threshold speed vThreshold valueChanging the sixth speed with a slope A6Is set to be smaller than the fifth speed change slope a5Absolute value of (d); when the throttle speed v of the forklift truckThrottle valveGreater than the low-speed inching threshold speed vThreshold valueChanging the sixth speed with a slope A6Is set equal to the fifth speed variation slope a5Absolute value of (a).
In other words, the present embodiment varies the accelerator speed vThrottle valveAnd a low speed inching threshold speed vThreshold valueComparing, and determining the sixth speed change slope A according to the relationship between the two6The size of (2).
Wherein, when the reference velocity vReference toLess than or equal to low-speed jogging threshold speed vThreshold valueAnd the throttle speed vThrottle valveLess than or equal to low speedMicromotion threshold speed vThreshold valueThe speed change slope of the jogging region is used as the sixth speed change slope A6. When reference velocity vReference toLess than or equal to low-speed jogging threshold speed vThreshold valueAnd the throttle speed vThrottle valveGreater than the low-speed inching threshold speed vThreshold valueThe speed change slope in the inflection point outside the jogging region is used as the sixth speed change slope A6. When reference velocity vReference toGreater than the low-speed inching threshold speed vThreshold valueAnd with reference to the velocity vReference toVelocity v less than or equal to the knee pointInflection pointThe speed change slope in the inflection point outside the jogging region is used as the sixth speed change slope A6. When reference velocity vReference toGreater than the low-speed inching threshold speed vThreshold valueAnd with reference to the velocity vReference toVelocity v greater than inflection pointInflection pointUsing the speed change slope after the inflection point as the sixth speed change slope A6。
In this embodiment, the micro-motion region velocity change slope and the post-inflection-point velocity change slope are respectively smaller than the intra-inflection-point velocity change slope outside the micro-motion region.
Example 10:
the present embodiment provides a speed control method of a forklift, and in addition to the technical features of embodiment 9 described above, the present embodiment further includes the following technical features.
According to the moment variation trend Delta T of the driving motor of the forklifteFor the fourth speed change slope A4Adjusting the absolute value of the absolute value; wherein, the moment variation trend Delta T of the driving motor is judgedeIncreasing, then increasing the fourth speed change slope A4Determining the torque variation trend Delta T of the driving motoreDecreasing, then decreasing the fourth speed change slope A4Absolute value of (a).
Using a fourth speed variation slope A4For reference velocity vReference toDuring the adjustment, i.e. the reference speed vReference toVelocity v of change to entering knee pointInflection pointPreviously, a constant power segment. In this interval, the present embodiment changes the slope a at the initially set fourth speed4Of (2) aOn the basis, the variation trend of the torque of the output of the driving motor of the forklift is judged, and the variation trend delta T of the torque of the driving motor is determined according to the variation trend delta T of the torque of the driving motoreAdjusting the fourth speed variation slope A4。
For example, an ac motor may be used to vector control the speed of travel of the truck, at which time the drive motor torque TeThe following relationship is provided between the d-axis reference current and the q-axis reference current:
Te＝k×id×iq；
where k is a constant coefficient associated with the motor, idIs d-axis reference current, i, of the motorqFor the q-axis reference current of the motor, the change of the product of all d-axis reference current and q-axis reference current reflects the moment variation trend Delta T of the driving motore. The d-axis reference current is obtained by a flux weakening control current distribution algorithm.
Wherein, the torque variation trend Delta T of the driving motore＝Te(k)-Te(k-1). When the torque variation trend of the driving motor is delta TeIf it is greater than zero, the fourth speed change slope A is increased4Absolute value of (1), torque variation tendency Δ T of the drive motoreLess than zero, the fourth speed change slope A is reduced4Absolute value of (a).
The embodiment feeds back the torque variation trend of the driving motor to the speed plan for the forklift, so that the speed variation slope adopted in the speed plan control of the forklift can automatically adapt to the motor control system.
Example 11:
this embodiment provides a forklift, and the forklift implements the steps of the method for controlling the speed of the forklift according to any embodiment of the present invention. Optionally, the forklift of this embodiment is an electric forklift. The speed control method of the forklift of any embodiment of the invention is adopted to control the forklift of the embodiment, so that the reference speed v of the forklift of the embodimentReference toCan obtain the initiative and adjust, from this, can improve the fork truck's of this embodiment driving experience.
In summary, the embodiment of the invention has the following beneficial effects:
1. reference speed v of fork truck of the embodiment of the inventionReference toMaking active adjustments so that the actual speed vPractice ofAnd a reference velocity vReference toCan track and match each other. Compared to a reference velocity vReference toRelated art limited to a certain value or range, the present embodiment actively couples the reference velocity vReference toThe adjustment is carried out to plan the traveling speed of the forklift better, and therefore the driving experience of the forklift is improved.
2. Embodiments of the invention are directed to reference velocity vReference toBy stepwise varying the speed change slope versus the reference speed v when making the adjustmentReference toLinear regulation is carried out so that the reference speed vReference toThe change in (c) is more gentle.
3. The embodiment of the invention feeds back the torque variation trend of the driving motor to the speed plan for the forklift, thereby enabling the speed variation slope adopted in the speed plan control of the forklift to automatically adapt to the motor control system.
In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A method for controlling the speed of a forklift, comprising:
and in the process that the running speed of the forklift changes from the current running speed to the target running speed, controlling the reference speed according to the difference between the actual speed and the reference speed of the forklift.
2. The method for controlling the speed of the forklift according to claim 1, wherein the controlling the reference speed according to the difference between the actual speed of the forklift and the reference speed specifically includes:
determining that the difference is less than or equal to a first difference threshold, and controlling the reference speed to decrease; or
Judging that the difference is larger than a first difference threshold value and smaller than or equal to a second difference threshold value, and controlling the reference speed to be kept unchanged; or
And judging that the difference is larger than a second difference threshold value and smaller than or equal to a third difference threshold value, and controlling the reference speed to be increased.
3. The method of controlling the speed of a forklift according to claim 1, wherein after the control of the reference speed is performed based on a difference between the actual speed of the forklift and the reference speed, the method further comprises:
determining that the reference speed is greater than the throttle speed of the forklift, and reducing the reference speed to the throttle speed; or
And judging that the reference speed is less than or equal to the accelerator speed of the forklift, and keeping the reference speed unchanged.
4. The method for controlling the speed of a forklift according to any one of claims 1 to 3, wherein the controlling the reference speed based on the difference between the actual speed of the forklift and the reference speed specifically includes:
and linearly adjusting the reference speed by adopting at least two speed change slopes.
5. The method for controlling the speed of a forklift truck according to claim 4, wherein the linearly adjusting the reference speed using at least two speed change slopes specifically includes:
adjusting the reference speed from zero speed to a low-speed inching threshold speed by adopting a first speed change slope;
adjusting the reference speed from the low-speed inching threshold speed to an inflection point speed by adopting a second speed change slope;
adjusting the reference speed from the knee point speed to a maximum speed by adopting a third speed change slope;
wherein an absolute value of the first speed change slope is less than or equal to an absolute value of the second speed change slope, and an absolute value of the third speed change slope is less than an absolute value of the second speed change slope.
6. The method of controlling the speed of a forklift according to claim 5,
when the accelerator speed of the forklift is less than or equal to the low-speed inching threshold speed, the absolute value of the change slope of the first speed is less than the absolute value of the change slope of the second speed;
and when the accelerator speed of the forklift is greater than the low-speed inching threshold speed, the absolute value of the change slope of the first speed is equal to the absolute value of the change slope of the second speed.
7. The method of controlling the speed of a forklift according to claim 5,
adjusting the absolute value of the third speed change slope according to the torque change trend of the driving motor of the forklift;
and if the torque variation trend of the driving motor is judged to be increased, the absolute value of the third speed variation slope is increased, and if the torque variation trend of the driving motor is judged to be decreased, the absolute value of the third speed variation slope is decreased.
8. The method for controlling the speed of a forklift truck according to claim 4, wherein the linearly adjusting the reference speed using at least two speed change slopes specifically includes:
adjusting the reference speed from the maximum speed to an inflection point speed by adopting a fourth speed change slope;
adjusting the reference speed from the knee point speed to a low-speed inching threshold speed by adopting a fifth speed change slope;
adjusting the reference speed from the low-speed inching threshold speed to a zero speed by adopting a sixth speed change slope;
wherein an absolute value of the fourth speed change slope is smaller than an absolute value of the fifth speed change slope, and an absolute value of the sixth speed change slope is smaller than or equal to an absolute value of the fifth speed change slope.
9. The method of controlling the speed of a forklift according to claim 8,
when the accelerator speed of the forklift is less than or equal to the low-speed inching threshold speed, setting the absolute value of the sixth speed change slope to be less than the absolute value of the fifth speed change slope;
when the accelerator speed of the forklift is greater than the low-speed inching threshold speed, setting the absolute value of the sixth speed change slope equal to the absolute value of the fifth speed change slope;
and adjusting the absolute value of the fourth speed change slope according to the moment change trend of the driving motor of the forklift, increasing the absolute value of the fourth speed change slope when the moment change trend of the driving motor is judged to be increased, and decreasing the absolute value of the fourth speed change slope when the moment change trend of the driving motor is judged to be decreased.
10. A forklift truck characterized by the steps of implementing the speed control method of the forklift truck according to any one of claims 1 to 9.
CN202010306459.XA 2020-04-17 2020-04-17 Forklift and speed control method for forklift Active CN111469856B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010306459.XA CN111469856B (en) 2020-04-17 2020-04-17 Forklift and speed control method for forklift

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010306459.XA CN111469856B (en) 2020-04-17 2020-04-17 Forklift and speed control method for forklift

Publications (2)

Publication Number Publication Date
CN111469856A true CN111469856A (en) 2020-07-31
CN111469856B CN111469856B (en) 2021-11-02

Family

ID=71754002

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010306459.XA Active CN111469856B (en) 2020-04-17 2020-04-17 Forklift and speed control method for forklift

Country Status (1)

Country Link
CN (1) CN111469856B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114620650A (en) * 2022-03-11 2022-06-14 三一机器人科技有限公司 Forklift control method, electronic equipment and forklift

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103381812A (en) * 2012-05-01 2013-11-06 株式会社堀场制作所 Speed control device and program for speed control device
CN103561990A (en) * 2011-05-16 2014-02-05 斯堪尼亚商用车有限公司 Driver interaction pertaining to reference-speed-regulating cruise control
CN103921793A (en) * 2013-01-14 2014-07-16 罗伯特·博世有限公司 Method and apparatus for adaptive cruise control of motor vehicle using a manual gearbox
CN104284824A (en) * 2012-04-05 2015-01-14 斯堪尼亚商用车有限公司 Method and system for control of at least a speed regulator
CN104411561A (en) * 2012-06-27 2015-03-11 斯堪尼亚商用车有限公司 Vehicle speed and coasting control method and system
CN104903627A (en) * 2013-12-27 2015-09-09 株式会社小松制作所 Forklift and forklift control method
CN107415954A (en) * 2017-07-24 2017-12-01 大陆汽车车身电子系统（芜湖）有限公司 The method and instrument of car speed are shown under cruise pattern
CN107985309A (en) * 2016-10-27 2018-05-04 郑州宇通客车股份有限公司 A kind of segmented vehicle constant-speed traveling control method
US20180178767A1 (en) * 2016-12-23 2018-06-28 Robert Bosch Gmbh Method and system for determining vehicle speed using vertical and longitudinal acceleration sensors
CN108340916A (en) * 2017-01-23 2018-07-31 郑州宇通客车股份有限公司 Constant speed of vehicle travel control method and control device
CN108437978A (en) * 2018-05-14 2018-08-24 武汉理工大学 Four wheel hub electricity drive vehicle running surface automatic identification and stability integrated control method
US20180297594A1 (en) * 2015-10-30 2018-10-18 Hitachi Automotive Systems, Ltd. Vehicular motion control device and method
CN108860146A (en) * 2018-06-11 2018-11-23 浙江国自机器人技术有限公司 A kind of double method for control speed, system and relevant apparatus driven
CN109835335A (en) * 2017-11-28 2019-06-04 蔚来汽车有限公司 Electric vehicle cruise control method and system and vehicle, controller and storage medium
CN110550045A (en) * 2019-09-09 2019-12-10 奇瑞汽车股份有限公司 Speed planning and tracking method, device and storage medium

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103561990A (en) * 2011-05-16 2014-02-05 斯堪尼亚商用车有限公司 Driver interaction pertaining to reference-speed-regulating cruise control
CN104284824A (en) * 2012-04-05 2015-01-14 斯堪尼亚商用车有限公司 Method and system for control of at least a speed regulator
CN103381812A (en) * 2012-05-01 2013-11-06 株式会社堀场制作所 Speed control device and program for speed control device
CN104411561A (en) * 2012-06-27 2015-03-11 斯堪尼亚商用车有限公司 Vehicle speed and coasting control method and system
CN103921793A (en) * 2013-01-14 2014-07-16 罗伯特·博世有限公司 Method and apparatus for adaptive cruise control of motor vehicle using a manual gearbox
CN104903627A (en) * 2013-12-27 2015-09-09 株式会社小松制作所 Forklift and forklift control method
US20180297594A1 (en) * 2015-10-30 2018-10-18 Hitachi Automotive Systems, Ltd. Vehicular motion control device and method
CN107985309A (en) * 2016-10-27 2018-05-04 郑州宇通客车股份有限公司 A kind of segmented vehicle constant-speed traveling control method
US20180178767A1 (en) * 2016-12-23 2018-06-28 Robert Bosch Gmbh Method and system for determining vehicle speed using vertical and longitudinal acceleration sensors
CN108340916A (en) * 2017-01-23 2018-07-31 郑州宇通客车股份有限公司 Constant speed of vehicle travel control method and control device
CN107415954A (en) * 2017-07-24 2017-12-01 大陆汽车车身电子系统（芜湖）有限公司 The method and instrument of car speed are shown under cruise pattern
CN109835335A (en) * 2017-11-28 2019-06-04 蔚来汽车有限公司 Electric vehicle cruise control method and system and vehicle, controller and storage medium
CN108437978A (en) * 2018-05-14 2018-08-24 武汉理工大学 Four wheel hub electricity drive vehicle running surface automatic identification and stability integrated control method
CN108860146A (en) * 2018-06-11 2018-11-23 浙江国自机器人技术有限公司 A kind of double method for control speed, system and relevant apparatus driven
CN110550045A (en) * 2019-09-09 2019-12-10 奇瑞汽车股份有限公司 Speed planning and tracking method, device and storage medium

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
徐家祥: "站驾式叉车行驶速度控制的改进", 《工程机械与维修》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114620650A (en) * 2022-03-11 2022-06-14 三一机器人科技有限公司 Forklift control method, electronic equipment and forklift

Also Published As

Publication number Publication date
CN111469856B (en) 2021-11-02

Similar Documents

Publication Publication Date Title
CN109624979B (en) Constant-speed cruise torque control method and system
CN108394313B (en) Four-wheel drive electric vehicle torque control distribution method based on slip ratio
CN107985309B (en) Sectional type vehicle constant-speed driving control method
RU2720227C1 (en) Electric vehicle electric motor control method and electric vehicle electric motor control device
JP4589979B2 (en) Control device for hydraulic traveling vehicle
EP3072767B1 (en) Vehicle speed limit apparatus
WO2011152128A1 (en) Torque response control apparatus for electric motor of vehicle
JPH08228404A (en) Drive controller for electric vehicle and controlling method therefor
CN106817058B (en) electric forklift drive control method and device and electric forklift
JPWO2010100761A1 (en) Vehicle travel control device
CN111469856B (en) Forklift and speed control method for forklift
US11897465B2 (en) Vehicle control device
CN110630375A (en) Engine braking power control method and system
CN113661101A (en) Brake control device, brake method and brake system for a rail vehicle
US20230382385A1 (en) Braking force control device
CN106958182B (en) Wheeled paver traveling system and control method thereof
WO2018221747A1 (en) Travel control device, vehicle, travel control method, and travel control program
JP2003267698A (en) Electric vehicle
CN1302346C (en) Method and device for controlling speed of IC engine
JP2023001144A (en) Controller, method, and program
JP2020011582A (en) Drive force control device
JP3680701B2 (en) Vehicle speed control device
CN113119943A (en) Vehicle control method and system and vehicle
JP6438273B2 (en) Engine generator control device and mining dump truck equipped with the same
WO2022085082A1 (en) Driving force control method and driving force control device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20220523

Address after: 410100 2nd floor, No.3 workshop, Sany industrial city, Changsha Economic and Technological Development Zone, Changsha City, Hunan Province

Patentee after: HUNAN SANY INTELLIGENT CONTROL EQUIPMENT Co.,Ltd.

Address before: 410100 31 industrial city, Changsha economic and Technological Development Zone, Hunan

Patentee before: HUNAN SANYI ELECTRIC CONTROL TECHNOLOGY Co.,Ltd.

TR01 Transfer of patent right