CN114454958A - Aerial work platform and control method and control system thereof - Google Patents
Aerial work platform and control method and control system thereof Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D11/00—Steering non-deflectable wheels; Steering endless tracks or the like
- B62D11/02—Steering non-deflectable wheels; Steering endless tracks or the like by differentially driving ground-engaging elements on opposite vehicle sides
- B62D11/04—Steering non-deflectable wheels; Steering endless tracks or the like by differentially driving ground-engaging elements on opposite vehicle sides by means of separate power sources
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
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Abstract
The invention belongs to the field of engineering machinery, and discloses an aerial work platform, a control method and a control system thereof, which can control the differential rotation of an inner motor assembly (3) and an outer motor assembly (4) of the aerial work platform by utilizing a differential control technology when the aerial work platform turns to walk, wherein the core of the differential control technology is that the rotating speeds required by the inner motor assembly (3) and the outer motor assembly (4) are respectively determined by acquiring the current turning and walking information of the aerial work platform, so that an inner driving wheel (7) and an outer driving wheel (8) can be in pure rolling contact with the ground, the risks of dragging and slipping phenomena are reduced, the walking energy consumption of the platform is reduced, the service lives of the inner motor assembly and the outer motor assembly are prolonged, the use of the platform under the smooth ground is facilitated, and the control performance and the control experience can be improved.
Description
Technical Field
The invention relates to the technical field of engineering machinery, in particular to a control method for an aerial work platform, a control system for the aerial work platform and the aerial work platform.
Background
At present, when an aerial work platform driven by a motor to walk turns, two driving motors (namely, an inner motor and an outer motor) for driving two driving wheels (namely, an inner driving wheel and an outer driving wheel) to rotate are controlled by constant speed or constant power respectively. Theoretically, the corresponding turning radii of the two driving wheels are different, and on the premise that the speeds of the turning angles of the platform are the same, the two driving wheels are guaranteed to be in pure rolling contact with the ground, and the rotating speeds of the two driving wheels should be different theoretically. Therefore, in the current constant-speed or constant-power motor control mode, although the control requirement is low and easy to realize, the actual rotating speeds of the two driving motors are not matched with the theoretical rotating speeds of the two driving wheels, so that pure rolling contact between the two driving wheels and the ground cannot be maintained, and the two driving wheels are forcibly dragged by the platform vehicle body to inevitably generate dragging slip or dragging rotation.
When the phenomenon of dragging and sliding or dragging and rotating occurs, the friction between the tire and the ground is increased, so that the walking energy consumption is increased, and the service life of the driving motor is shortened. In addition, the occurrence of dragging and slipping is not beneficial to the use of the aerial work platform on a smooth ground, and the actual turning radius of the platform is larger than a theoretical value, so that the turning performance and the control experience are influenced.
In summary, the driving motor control technology adopted by the existing aerial work platform cannot avoid the damage of dragging and sliding and dragging rotation to the platform and the ground environment, is not beneficial to the long-term efficient, healthy and safe operation of the platform, and influences the operation experience, so that the platform still has a great improvement space.
Disclosure of Invention
Aiming at least one defect or defect in the prior art, the invention provides an aerial work platform, a control method and a control system thereof, which can perform differential control on an inner motor and an outer motor when the platform turns to walk so as to reduce the risks of dragging and sliding of a driving wheel, reduce energy consumption, prolong the service life of the motor, enable the platform to be suitable for being used under the smooth ground and improve the operation experience.
In order to achieve the above object, a first aspect of the present invention provides a control method for an aerial work platform, comprising:
acquiring steering and walking information of the aerial work platform during steering and walking;
and controlling an inner motor assembly and an outer motor assembly of the aerial work platform to rotate in a differential mode according to the steering and walking information, wherein the inner motor assembly and the outer motor assembly are respectively used for driving an inner driving wheel and an outer driving wheel of the aerial work platform to rotate.
Optionally, the steering and traveling information includes a vehicle body traveling speed V of the aerial work platform and a mechanism displacement S of a steering mechanism, and controlling differential rotation of an inner motor assembly and an outer motor assembly of the aerial work platform according to the steering and traveling information includes:
determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
according to the Ackerman steering geometry, the steering angle delta of the vehicle body, the running speed V of the vehicle body and the radius r of the driving wheel of the inner side driving wheelinAnd a drive wheel radius r of the outer drive wheeloutRespectively calculating the motor rotating speed n of the inner motor assemblyinAnd the motor speed n of the outer motor assemblyout。
Optionally, the inner driving wheel and the outer driving wheel are both rear driving wheels, and the vehicle body steering angle δ, the vehicle body traveling speed V, and the driving wheel radius r of the inner driving wheel are determined according to ackermann steering geometryinAnd a drive wheel radius r of the outer drive wheeloutRespectively calculating the motor rotating speed n of the inner motor assemblyinAnd the motor speed n of the outer motor assemblyoutIn (1), satisfy:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout；
w is the wheel track of the inner side driving wheel and the outer side driving wheel, and L is the wheel base of the aerial work platform.
Optionally, in determining the vehicle body steering angle δ of the aerial work platform according to the mechanism displacement S, the following conditions are satisfied:
δ＝k*S+b；
wherein k and b are preset constants.
Optionally, the steering mechanism includes a telescopic power cylinder, and the mechanism displacement S is an extension length of a telescopic rod of the telescopic power cylinder.
Optionally, before obtaining steering and traveling information when the aerial work platform steers and travels, the mechanism displacement S of the steering mechanism is detected.
Optionally, the aerial work platform is driven to turn to walk by receiving a turning walking instruction, the turning walking instruction comprises a walking instruction carrying the walking speed V of the vehicle body, and the walking speed V of the vehicle body is extracted from the walking instruction when the turning walking information of the aerial work platform during turning to walk is obtained.
Optionally, when the aerial work platform turns to walk, the turning and walking information is displayed through a visualization technology.
A second aspect of the invention provides a control system for an aerial work platform comprising:
the steering mechanism is used for driving the aerial work platform to steer;
the traveling mechanism comprises an inner side motor assembly and an outer side motor assembly which are respectively used for driving an inner side driving wheel and an outer side driving wheel of the aerial work platform to rotate; and
a processing device in communication with the steering mechanism, the inboard motor assembly, and the outboard motor assembly, respectively, and configured to:
acquiring steering and walking information of the aerial work platform during steering and walking;
and controlling the differential rotation of the inner motor assembly and the outer motor assembly according to the steering and walking information.
Optionally, the steering information includes a vehicle body traveling speed V of the aerial work platform and a mechanism displacement amount S of the steering mechanism, and the processing device is further configured to:
determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
according to the Ackerman steering geometric relation, the steering angle delta of the vehicle body, the running speed V and the driving speed of the vehicle bodyRadius r of the inner driving wheelinAnd a drive wheel radius r of the outer drive wheeloutRespectively calculating the motor rotating speed n of the inner motor assemblyinAnd the motor speed n of the outer motor assemblyout。
Optionally, the inboard drive wheel and the outboard drive wheel are both rear drive wheels, the processing device further configured to:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout；
w is the wheel track of the inner side driving wheel and the outer side driving wheel, and L is the wheel base of the aerial work platform.
Optionally, the processing device is further configured to:
δ＝k*S+b；
wherein k and b are preset constants.
Optionally, the steering mechanism includes a telescopic power cylinder, and the mechanism displacement S is an extension length of a telescopic rod of the telescopic power cylinder.
Optionally, the steering mechanism includes a displacement sensor for detecting the amount of mechanism displacement S, and the processing device is in communication with the displacement sensor and is further configured to be able to acquire the amount of mechanism displacement S from the displacement sensor.
Optionally, the control system further includes an instruction generating device for generating a steering walking instruction to drive the aerial work platform to steer and walk, the steering walking instruction includes a walking instruction carrying the vehicle body walking speed V, and the processing device is in communication with the instruction generating device and is further configured to be capable of extracting the vehicle body walking speed V from the walking instruction.
Optionally, the control system further comprises a visualization device capable of displaying the turn-and-walk information.
A third aspect of the invention provides an aerial work platform comprising a control system for an aerial work platform as described above.
Through the technical scheme of the invention, the aerial work platform can control the inner side motor assembly and the outer side motor assembly to rotate in a differential speed manner by utilizing a differential control technology when the aerial work platform turns to walk, and the core of the differential control technology is that the rotating speeds required by the inner side motor assembly and the outer side motor assembly are respectively determined by acquiring the current turning and walking information of the aerial work platform, so that the inner side driving wheel and the outer side driving wheel can be in pure rolling contact with the ground, the risk of dragging and slipping phenomena is reduced, the walking energy consumption of the platform is reduced, the service lives of the inner side motor assembly and the outer side motor assembly are prolonged, the use of the platform under the smooth ground is facilitated, and the control performance and the control experience can be improved.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic flow chart of a control method for an aerial work platform according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of an alternative control method for an aerial work platform according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of Ackerman steering geometry of an aerial work platform according to an embodiment of the present invention;
FIG. 4 is a schematic view of an alternative control system for an aerial work platform according to embodiments of the present invention;
FIG. 5 is a schematic view of an alternative control system for an aerial work platform according to embodiments of the present invention;
FIG. 6 is intended primarily to illustrate an alternative steering mechanism in accordance with an embodiment of the present invention;
FIG. 7 is primarily intended to illustrate the steering mechanism of FIG. 6 from a top view;
fig. 8 is a schematic diagram illustrating a comparison between a fitting straight line and a simulation result in an embodiment of the present invention, where the fitting straight line is a linear equation of two variables including a steering angle δ of a vehicle body and a displacement S of a mechanism, which are obtained by fitting with a computer, and the simulation result is a series of feature points obtained by simulating a corresponding relationship between the steering angle δ of the vehicle body and the displacement S of the mechanism in an actual situation with a modeling software.
Description of reference numerals:
1 instruction generating apparatus 2 processing apparatus
3 inner motor assembly 4 outer motor assembly
5 steering mechanism 6 motor driver
7 inner side driving wheel 8 outer side driving wheel
9 inner steering wheel 10 outer steering wheel
3a inner motor body and 4a outer motor body
5a electric cylinder 5b connecting cross bar
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
In embodiments of the invention, where the context requires otherwise, the use of directional terms such as "upper, lower, top and bottom" is generally intended in the orientation shown in the drawings or the positional relationship of the various components in a vertical, vertical or gravitational orientation.
The invention will be described in detail below with reference to exemplary embodiments and with reference to the accompanying drawings.
Referring to fig. 1, 3 and 4, a first exemplary embodiment of the present invention provides a control method for an aerial work platform, the method mainly including:
step S1: acquiring steering and walking information when the aerial work platform steers and walks;
step S2: and controlling the inner motor assembly 3 and the outer motor assembly 4 of the aerial work platform to rotate in a differential speed mode according to the steering and walking information, wherein the inner motor assembly 3 and the outer motor assembly 4 are respectively used for driving an inner driving wheel 7 and an outer driving wheel 8 of the aerial work platform to rotate.
By adopting the method, the aerial work platform can control the inner motor assembly 3 and the outer motor assembly 4 to rotate in a differential speed manner when the aerial work platform turns to walk, and the method is characterized in that the rotating speeds required by the inner motor assembly 3 and the outer motor assembly 4 are respectively determined by acquiring the current turning and walking information of the aerial work platform, so that the inner driving wheel 7 and the outer driving wheel 8 rotate in a differential speed manner to keep the pure rolling contact between the tire and the ground.
Under the condition of keeping the pure rolling contact of the tire and the ground, the risk of dragging and sliding and dragging phenomena can be effectively reduced, so that the abrasion of the tire is reduced, the walking energy consumption of the platform is reduced, the rotating speeds of the inner motor assembly and the outer motor assembly are respectively matched with the rotating speeds of the inner driving wheel and the outer driving wheel all the time so as to prolong the service life of the inner motor assembly and the outer motor assembly, tire friction marks are prevented from being left on the ground, the platform is suitable for being used under the bright and clean ground, and the deviation of the actual turning radius of the platform and a theoretical value can be well controlled within a preset allowable range so as to improve the control performance and the control experience.
It should be noted that, although fig. 3 illustrates the aerial work platform being driven to travel by the rear-drive method, the method of the present exemplary embodiment is also applicable to the case where the aerial work platform is driven to travel by the front-drive method. For example, the inner steering wheel 9 and the outer steering wheel 10 in the figure may be the inner driving wheel 7 and the outer driving wheel 8, respectively, that is, in the front driving mode, the inner steering wheel 9 and the outer steering wheel 10 both have a steering control function and a running drive function.
In an alternative or preferred embodiment, the steering information includes a vehicle body traveling speed V of the aerial work platform and a mechanism displacement amount S of the steering mechanism 5, and referring to fig. 2, step S2 includes:
step S21: determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
step S22: according to Ackermann steering geometry, the steering angle delta of the vehicle body, the walking speed V of the vehicle body, the radius r of the driving wheel of the inner driving wheel 7inAnd the driving wheel radius r of the outer driving wheel 8outRespectively calculate the motor rotating speed n of the inner motor assembly 3inAnd the motor speed n of the outer motor assembly 4out。
Step S22 is intended to calculate the required motor speed ninAnd motor speed noutSo that the inner driving wheel 7 and the outer driving wheel 8 do not generate dragging and slipping when the platform turns to walk, and the required motor speed n is ensured at the momentinThe required motor speed n is the same as the required speed of the inner drive wheel 7outThe same rotational speed as the rotational speed of the outer drive wheel 8 is required, and therefore the purpose of step S22 corresponds to calculating the required rotational speed of the inner drive wheel 7 and the rotational speed of the outer drive wheel 8. In addition, due to the radius r of the driving wheelinAnd radius r of the driving wheeloutThe two parameters can be regarded as known constants with the same value because the two parameters are determined when the aerial work platform leaves the factory. It can thus be seen that the desired drive wheel speed V of the inner drive wheel 7 can first be determinedinAnd the driving wheel speed V of the outside driving wheel 8outThe required rotational speed of the inner drive wheel 7 and the rotational speed of the outer drive wheel 8, i.e. the required motor speed n, can be calculated from the known relationship of linear speed, radius and rotational speedinAnd motor speed nout。
Referring to fig. 3, the embodiment calculates the required driving wheel speed V by constructing an ackermann steering geometry of the aerial work platforminAnd driving wheel speed Vout。
It is known that, according to ackerman steering geometry, when a vehicle is turning around a curve, the centers of the four wheel paths should substantially meet the instantaneous steering center O on the extension of the rear axle of the vehicle, in order to ensure that both the front and rear wheels are in pure rolling contact with the ground (i.e. no dragging and rolling occurs).
In fig. 3, the instantaneous turning radius r when the center position on the vehicle front axle connecting the inner steering wheel 9 and the outer steering wheel 10 turns around the instantaneous turning center O0The instantaneous turning radius R at the time of turning around the instantaneous turning center O at the center position on the rear axle connecting the inner side drive wheel 7 and the outer side drive wheel 8 is0The instantaneous turning radius of the inner side driving wheel 7 when turning around the instantaneous turning center O is RinThe instantaneous turning radius when the outside drive wheel 8 turns around the instantaneous turning center O is RoutThe angular velocity of the aerial work platform when turning around the instantaneous steering center O is omega0The wheelbase of the aerial work platform is L and can be considered as a known constant, the wheelbase of the inner driving wheel 7 and the outer driving wheel 8 is W and can be considered as a known constant, and the steering angle of the inner steering wheel 9 is deltainThe steering angle of the outer steering wheel 10 is δoutThe vehicle body steering angle δ and the vehicle body traveling speed V mentioned in step S22 are also indicated in fig. 3.
After the meanings of the parameters in fig. 3 are clarified, it can be found that the driving wheel speed V can be completely deduced by using the ackerman steering geometric relationship under the condition that the values of the vehicle body steering angle δ, the vehicle body walking speed V, the vehicle wheel base L and the vehicle wheel base W are all determinedinAnd driving wheel speed VoutAnd the mathematical relation formula of the steering angle delta of the vehicle body, the traveling speed V of the vehicle body, the wheel base L and the wheel base W. The values of the wheel base L and the wheel base W depend on the actual size of the aerial work platform, the vehicle body steering angle δ can be determined after step S21 is executed, and the vehicle body traveling speed V can be determined after step S1 is executed.
It can be seen that, in the process of executing step S22, it is possible to calculate the required driving wheel speed VinAnd driving wheel speed VoutThen according to a known drive wheel radius rinAnd radius r of the driving wheeloutThe desired rotational speed of the inner drive wheel 7 and the desired rotational speed of the outer drive wheel 8, i.e. the desired rotational speed of the electric motor, can finally be calculatedninAnd motor speed nout。
In an alternative or preferred embodiment, the inner drive wheel 7 and the outer drive wheel 8 are both rear drive wheels, and in this case in step S22, the following relation is satisfied:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout。
according to the geometry of fig. 3, the above-mentioned relationships can be combined by the following 1) to 4):
1)R0＝L/tan(δ)；
2)V＝ω0*R0；
3)Vin＝ω0*Rin＝ω0*(R0-W/2)，Vout＝ω0*Rout＝ω0*(R0+W/2)；
4)nin＝Vin/2πrin，nout＝Vout/2πrout。
similarly, when the aerial work platform is driven to walk in a forerunner mode, the rotating speed n of the motor can be obtained according to the geometric relation of the figure 3inSteering angle delta with vehicle body, vehicle body traveling speed V, vehicle wheel base L, wheel base W and driving wheel radius rinAnd obtaining the motor speed noutSteering angle delta with vehicle body, vehicle body traveling speed V, vehicle wheel base L, wheel base W and driving wheel radius routThe relational expression (c) of (c). In the front-wheel drive mode, the turning radius r in fig. 3 should be used0Rather than the turning radius R0And (5) carrying out relation derivation.
It should be noted that the drive wheel speed V is indirectly obtained from the vehicle body steering angle δinAnd driving wheel speed VoutRather than by steering angle deltainAnd steering angle deltaoutDirectly determined due to the steering angle deltainAnd steering angle deltaoutThe precise relationship with the displacement S of the mechanism is complicated and not conducive to programming of the controller. The relationship between the steering angle delta and the displacement S of the mechanismThe method is obtained by fitting through a computer tool in advance, is more simplified in calculation, and is more beneficial to controller programming.
In an alternative or preferred embodiment, an example of a simple relational expression of the vehicle body steering angle δ and the mechanism displacement amount S is provided by fitting with a computer tool.
First, the vehicle body steering angle δ is approximated. The value of the steering angle delta of the vehicle body is between the steering angle deltainAnd steering angle deltaoutIn between, it may be: delta is (delta)in+δout)/2。
Then, two-dimensional modeling is carried out according to size constraint by utilizing modeling software, a series of characteristic points are taken for simulation calculation, so that values of a plurality of vehicle body steering angles delta and values of a plurality of mechanism displacement quantities S which correspond to each other one by one under the actual condition are simulated, and the following table is arranged:
| s(mm) | 0 | 1.9 | 4.3 | 7.2 | 10.4 | 14.1 | 18.2 | 22.5 | 27.2 | 32.1 | 37.2 | 42.6 | 48 | 53.4 | 58.8 |
| δin(°) | -52.4 | -50.5 | -48.2 | -45.5 | -42.5 | -39.1 | -35.5 | -31.7 | -27.6 | -23.4 | -19 | -14.4 | -9.7 | -4.9 | 0 |
| δout(°) | -70 | -65 | -60 | -55 | -50 | -45 | -40 | -35 | -30 | -25 | -20 | -15 | -10 | -5 | 0 |
| δ(°) | -61.2 | -57.8 | -54.1 | -50.3 | -46.3 | -42.1 | -37.8 | -33.4 | -28.8 | -24.2 | -19.5 | -14.7 | -9.85 | -4.95 | 0 |
| s(mm) | 64.1 | 69.3 | 74.2 | 78.9 | 83.2 | 87.2 | 90.9 | 94.3 | 97.2 | 99.8 | 102 | 103.7 | 105 | 105.9 |
| δin(°) | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 |
| δout(°) | 4.9 | 9.7 | 14.4 | 19 | 23.4 | 27.6 | 31.7 | 35.5 | 39.1 | 42.5 | 45.5 | 48.2 | 50.5 | 52.4 |
| δ(°) | 4.95 | 9.85 | 14.7 | 19.5 | 24.2 | 28.8 | 33.35 | 37.75 | 42.05 | 46.25 | 50.25 | 54.1 | 57.75 | 61.2 |
and fitting multiple groups of corresponding data of the steering angle delta of the vehicle body and the displacement S of the mechanism in the upper table by using a Matlab tool and a fitting formula 5):
wherein, fitting formula 5) is: δ — k × S + b;
by computer fitting, k is 1.0516 and b is-59.2402, so that the fitting formula 5) is formed as a linear binary equation including two variables of the vehicle body steering angle δ and the mechanism displacement amount S. For example, when the linear equation of two elements is preset in the controller, k and b are equivalent to preset constants, so that the corresponding value of the mechanism displacement S can be calculated only by inputting a certain value of the vehicle body steering angle δ.
The computer fitting method can be applied to aerial work platforms with different structural parameters, when the structural parameters of the aerial work platforms are different, the multiple groups of corresponding data of the steering angle delta of the vehicle body and the mechanism displacement S in the upper table are different, but fitting is carried out through a Matlab tool and a fitting formula 5), and corresponding values of k and b can be solved, so that a corresponding binary primary equation comprising two variables of the steering angle delta of the vehicle body and the mechanism displacement S is obtained.
Returning again to the above example, when k is 1.0516 and b is-59.2402, the fitting equation 5) is δ 1.0516S-59.2402, and the calculation results of fitting equation 5) are plotted against the simulation calculation results in the above table (see fig. 8 in particular). It can be seen that the fitting formula 5) has a small error in the main steering working range (-60 ° to 60 °) of the aerial work platform in this example, and therefore the vehicle body steering angle δ obtained by the fitting formula 5) substantially coincides with the actual angle.
Therefore, in step S21, when the value of the mechanism displacement amount S has been determined in step S1, the value of the corresponding vehicle body steering angle δ can be obtained by δ — k × S + b.
In an alternative or preferred embodiment, the steering mechanism 5 comprises a telescopic power cylinder, and the steering angle of the inner steering wheel 9 and the outer steering wheel 10 can be controlled by the telescopic action of a telescopic rod of the telescopic power cylinder. At this time, the mechanism displacement S is the extension length of the telescopic rod. The embodiment is not limited to a specific type of the telescopic power cylinder, and may be an electric cylinder 5a (see fig. 5), a hydraulic cylinder, or the like.
For example, referring to fig. 6 and 7, the steering mechanism 5 includes an electric cylinder 5a and a connecting cross bar 5 b. One end of the electric cylinder 5a is pivotally connected to the outer steerable wheel 10 at position E and the other end is pivotally connected to the connecting crossbar 5B at position F, both ends of the connecting crossbar 5B are pivotally connected to the outer steerable wheel 10 and the inner steerable wheel 9 at positions C, D respectively, the outer steerable wheel 10 is pivotally connected to the chassis of the high-altitude working platform at position a, and the inner steerable wheel 9 is pivotally connected to the chassis at position B. Under the telescopic action of the electric cylinder 5a and the transmission action of the connecting cross rod 5b, the inner steering wheel 9 and the outer steering wheel 10 are controlled to steer corresponding angles.
In an alternative or preferred embodiment, the mechanism displacement amount S of the steering mechanism 5 is detected before the execution of step S1. In other words, after the aerial work platform receives the steering and traveling command (including the steering command and the traveling command), the steering mechanism 5 is driven to steer the inner steerable wheels 9 and the outer steerable wheels 10, and in the process, the steering mechanism 5 is detected to determine the mechanism displacement S, and then step S1 is executed to obtain the detected mechanism displacement S.
Of course, the present exemplary embodiment does not exclude the case where the information of the mechanism displacement amount S is prestored in the steering command. That is, when the aerial work platform is driven to steer walking by receiving a steering walking command (including a steering command and a walking command), the mechanism displacement amount S can be directly extracted from the steering command when step S1 is executed.
In an alternative or preferred embodiment, the walking command carries information of the vehicle body walking speed V. When the aerial work platform is driven to steer to travel by receiving the steering travel command (including the steering command and the travel command), the vehicle body travel speed V can be directly extracted from the travel command when step S1 is executed.
In an alternative or preferred embodiment, when the aerial work platform turns to walk, the turning and walking information is displayed through a visualization technology. The visualization technology can convert steering information in the steering and walking information into images of steering angles of the inner steering wheel 9 and the outer steering wheel 10 and the like so as to visually display the current steering wheel state. Compare with the mode that present operation personnel can only be through overlooking the directive wheel on the platform, effectively reduce safe risk, even rise the platform moreover, can not cause operation personnel's the observation degree of difficulty to increase yet, consequently can improve security and convenience of traveling simultaneously.
Referring to fig. 4, a second exemplary embodiment of the present invention provides a control system for an aerial work platform capable of performing the above-described control method for an aerial work platform. Therefore, it is obvious that the embodiments of the control system described below can also obtain the technical effects brought by the corresponding embodiments of the method described above, and therefore, for the embodiments described below, only the additional technical effects brought by the structural features of the embodiments are described, so as to avoid repeated descriptions of the foregoing contents.
Specifically, the control system of the present exemplary embodiment mainly includes:
the steering mechanism 5 is used for driving the aerial work platform to steer;
the traveling mechanism comprises an inner motor assembly 3 and an outer motor assembly 4 which are respectively used for driving an inner driving wheel 7 and an outer driving wheel 8 of the aerial work platform to rotate; and
a processing device 2 in communication with the steering mechanism 5, the inner motor assembly 3 and the outer motor assembly 4, respectively, and configured to:
acquiring steering and walking information when the aerial work platform steers and walks;
and controlling the inner motor assembly 3 and the outer motor assembly 4 to rotate in a differential speed mode according to the steering and walking information.
Specifically, referring to fig. 5, the inner motor assembly 3 may include an inner motor body 3a and an inner motor driver, the outer motor assembly 4 may include an outer motor body 4a and an outer motor driver, and the steering mechanism 5 includes an actuator and a steering driver. At this time, the processing device 2 communicates with an inside motor driver, an outside motor driver and a steering driver, respectively, the inside motor body 3a communicates with the inside motor driver and is used for directly driving the inside driving wheel 7 to rotate, the outside motor body 4a communicates with the outside motor driver and is used for directly driving the outside driving wheel 8 to rotate, and an actuator in the steering mechanism 5 communicates with the steering driver and is used for driving the inside steering wheel 9 and the outside steering wheel 10 to steer. When performing differential control, the processing device 2 first sends a differential control signal to the inner motor driver and the outer motor driver, and then drives the inner motor body 3a and the outer motor body 4a to rotate at respective rotational speeds by the inner motor driver and the outer motor driver, respectively. When the steering control is performed, the processing device 2 first sends a steering control signal to the steering driver, and then drives the actuator to act through the steering driver.
Further, when the actuator of the steering mechanism 5 is the electric cylinder 5a, the steering actuator is a steering motor actuator. In this case, the control system of the present exemplary embodiment is applicable to a fully electric aerial work platform. And with continued reference to fig. 5, it is also possible to integrally provide the steering motor driver, the inside motor driver, and the outside motor driver as the motor driver 6 to simplify the structure of the control system.
In fig. 4, arrows directed from the processing device 2 to the inner motor assembly 3, the outer motor assembly 4 and the steering mechanism 5 respectively indicate corresponding control signal flow directions, and an arrow directed from the inner motor assembly 3 to the processing device 2 indicates the motor rotation speed ninThe arrow pointing from the outer motor assembly 4 to the processing apparatus 2 indicates the motor speed noutThe arrow directed to the processing device 2 by the steering mechanism 5 indicates the position feedback signal flow of the actuator (e.g., the feedback signal flow of the mechanism displacement amount S).
In fig. 5, arrows directed to the motor driver 6 by the processing device 2 indicate the flow direction of control signals, arrows directed to the inner motor body 3a, the outer motor body 4a, and the electric cylinder 5a by the motor driver 6 indicate the corresponding flow direction of control signals, respectively, and arrows directed to the motor driver 6 by the inner motor body 3a indicate the motor rotation speed ninThe arrow pointing from the outer motor body 4a to the motor driver 6 indicates the motor speed noutFlow of rotational speed feedback signalsTo this end, the arrow pointing from the electric cylinder 5a to the motor driver 6 indicates the flow direction of the position feedback signal of the electric cylinder 5a (i.e., the flow direction of the feedback signal of the mechanism displacement amount S), and the arrow pointing from the motor driver 6 to the processing device 2 indicates the flow direction of the total feedback signal including the motor rotation speed ninSpeed feedback signal, motor speed noutAnd a position feedback signal of the electric cylinder 5 a.
It can be seen that, the inner motor assembly 3 and the outer motor assembly 4 in the control system of the exemplary embodiment both have rotational speed monitoring and feedback functions, the steering mechanism 5 has position monitoring and feedback functions, the processing device 2 can communicate with the inner motor assembly 3, the outer motor assembly 4 and the steering mechanism 5 through buses, and besides the differential speed control of the inner motor assembly 3 and the outer motor assembly 4 can be realized by performing closed-loop control on the steering mechanism 5 by means of the processing device 2, accurate control of the motor rotational speed and the steering angle can be realized.
On the other hand, because the steering mechanism 5 has the position monitoring and feedback functions, on the basis, the steering mechanism 5 can be subjected to limit control so as to avoid the situation that the steering wheel cannot be automatically stopped after being steered to the extreme position and collides with the frame, and the frame structure is protected.
In an alternative or preferred embodiment, the steering information includes a vehicle body traveling speed V of the aerial work platform and a mechanism displacement amount S of the steering mechanism 5, and the processing device 2 is further configured to:
determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
according to the Ackerman steering geometric relation, the vehicle body steering angle delta, the vehicle body walking speed V and the driving wheel radius r of the inner side driving wheel 7inAnd the driving wheel radius r of the outer driving wheel 8outRespectively calculate the motor rotating speed n of the inner motor assembly 3inAnd the motor speed n of the outer motor assembly 4out。
In other words, when the aerial work platform turns to walk, the processing device 2 can calculate the rotating speed of the motor according to the preset program as long as the processing device acquires the vehicle body walking speed V and the mechanism displacement SninAnd motor speed noutThereby driving the inner motor assembly 3 and the outer motor assembly 4 to rotate in a differential speed manner.
In an alternative or preferred embodiment, the inboard drive wheel 7 and the outboard drive wheel 8 are both rear drive wheels, and the processing apparatus 2 is further configured to:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout；
wherein, W is the wheel track of the inner driving wheel 7 and the outer driving wheel 8, and L is the wheel base of the aerial work platform.
In an alternative or preferred embodiment, the processing device 2 is further configured to:
δ＝k*S+b；
wherein k and b are preset constants.
In an alternative or preferred embodiment, the steering mechanism 5 comprises a telescopic power cylinder, and the mechanism displacement S is the extension length of the telescopic rod of the telescopic power cylinder.
In an alternative or preferred embodiment, the steering mechanism 5 comprises a displacement sensor for detecting the amount of mechanism displacement S, and the processing device 2 is in communication with the displacement sensor and is further configured to be able to acquire the amount of mechanism displacement S from the displacement sensor. In other words, the displacement sensor is a component that implements the position monitoring and feedback functions of the steering mechanism 5.
In an alternative or preferred embodiment, referring to fig. 4 and 5, the control system further includes an instruction generating device 1 for generating a steering walking instruction to drive the aerial work platform to steer to walk, the steering walking instruction includes a walking instruction carrying a vehicle body walking speed V and also includes a steering instruction, and the processing device 2 is in communication with the instruction generating device 1 and is further configured to be able to extract the vehicle body walking speed V from the walking instruction.
Generally, the instruction generating device 1 is a platform handle, and an operator controls the platform handle to generate a steering and walking instruction. Certainly, the present embodiment does not exclude the possibility that the instruction generating device 1 is a fully automatic device, and when the instruction generating device 1 is a fully automatic device, the corresponding steering and traveling instruction can be automatically generated according to the actual operation condition without manual control, for example, in the case that the aerial platform encounters a road block, the instruction generating device 1 may be triggered to automatically generate an instruction for controlling the platform to retreat or steer.
In an alternative or preferred embodiment, the control system further comprises a visualization device capable of displaying turn-by-turn walking information. For example, the visualization device comprises a steering indicator lamp, a display screen or a holographic projector arranged on the working platform of the aerial work platform, so that the operator can intuitively observe the current steering and walking state of the platform when standing on the working platform.
The third exemplary embodiment of the present invention provides an aerial work platform provided with the above control system, and obviously, the aerial work platform has all the technical effects brought by the above control system, and therefore, the details are not repeated here.
Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details of the above embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present invention within the technical idea of the embodiments of the present invention, and the simple modifications all belong to the protection scope of the embodiments of the present invention.
It should be noted that, in the foregoing embodiments, various features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described in further detail in the embodiments of the present invention.
In addition, any combination of various different implementation manners of the embodiments of the present invention is also possible, and the embodiments of the present invention should be considered as disclosed in the embodiments of the present invention as long as the combination does not depart from the spirit of the embodiments of the present invention.
Claims (17)
1. A control method for an aerial work platform, comprising:
acquiring steering and walking information of the aerial work platform during steering and walking;
and controlling an inner motor assembly (3) and an outer motor assembly (4) of the aerial work platform to rotate in a differential speed mode according to the steering and walking information, wherein the inner motor assembly (3) and the outer motor assembly (4) are respectively used for driving an inner driving wheel (7) and an outer driving wheel (8) of the aerial work platform to rotate.
2. The control method for the aerial work platform as claimed in claim 1, wherein the steering walking information comprises a vehicle body walking speed V of the aerial work platform and a mechanism displacement amount S of a steering mechanism (5), and the controlling of differential rotation of the inner motor assembly (3) and the outer motor assembly (4) of the aerial work platform according to the steering walking information comprises:
determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
according to the Ackerman steering geometry, the vehicle body steering angle delta, the vehicle body traveling speed V and the driving wheel radius r of the inner side driving wheel (7)inAnd a drive wheel radius r of the outer drive wheel (8)outRespectively calculating the motor rotating speed n of the inner side motor assembly (3)inAnd the motor speed n of the outer motor assembly (4)out。
3. Control method for aerial work platforms according to claim 2, wherein the inboard driving wheel (7) and the outboard driving wheel (8) are both rear driving wheels, according to ackermann steering geometry, the vehicle body steering angle δ, the vehicle body walking speed V, the driving wheel radius r of the inboard driving wheel (7)inAnd a drive wheel radius r of the outer drive wheel (8)outRespectively calculating the motor rotating speed n of the inner side motor assembly (3)inAnd the motor speed n of the outer motor assembly (4)outIn (1), satisfy:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout；
w is the wheel track of the inner side driving wheel (7) and the outer side driving wheel (8), and L is the wheel base of the aerial work platform.
4. The control method for the aerial work platform as claimed in claim 2, wherein in determining the body steering angle δ of the aerial work platform from the mechanism displacement amount S, it satisfies:
δ＝k*S+b；
wherein k and b are preset constants.
5. The control method for an aerial work platform according to claim 2, wherein the steering mechanism (5) comprises a telescopic power cylinder, and the mechanism displacement amount S is an extension length of a telescopic rod of the telescopic power cylinder.
6. The control method for the aerial work platform as claimed in claim 2, wherein the mechanism displacement amount S of the steering mechanism (5) is detected before steering travel information when the aerial work platform is steered to travel is acquired.
7. The control method for the aerial work platform as claimed in claim 2, wherein the aerial work platform is driven to steer to walk by receiving steering walking instructions, the steering walking instructions comprise walking instructions carrying the vehicle body walking speed V, and the vehicle body walking speed V is extracted from the walking instructions when steering walking information of the aerial work platform during steering walking is obtained.
8. The control method for the aerial work platform as claimed in any one of claims 1 to 7, wherein the steering walking information is displayed by a visualization technique when the aerial work platform is steering to walk.
9. A control system for an aerial work platform comprising:
the steering mechanism (5) is used for driving the aerial work platform to steer;
the traveling mechanism comprises an inner side motor assembly (3) and an outer side motor assembly (4) which are respectively used for driving an inner side driving wheel (7) and an outer side driving wheel (8) of the aerial work platform to rotate; and
a processing device (2) in communication with the steering mechanism (5), the inner motor assembly (3) and the outer motor assembly (4), respectively, and configured to:
acquiring steering and walking information of the aerial work platform during steering and walking;
and controlling the inner motor assembly (3) and the outer motor assembly (4) to rotate in a differential speed mode according to the steering and walking information.
10. The control system for an aerial work platform as defined in claim 9, wherein the steered walking information comprises a body walking speed V of the aerial work platform and a mechanism displacement amount S of the steering mechanism (5), the processing device (2) being further configured to:
determining a vehicle body steering angle delta of the aerial work platform according to the mechanism displacement S;
according to the Ackerman steering geometry, the vehicle body steering angle delta, the vehicle body traveling speed V and the driving wheel radius r of the inner side driving wheel (7)inAnd a drive wheel radius r of the outer drive wheel (8)outRespectively calculating the motor rotating speed n of the inner side motor assembly (3)inAnd the motor speed n of the outer motor assembly (4)out。
11. A control system for an aerial work platform as claimed in claim 10 wherein the inboard drive wheel (7) and the outboard drive wheel (8) are both rear drive wheels, the processing apparatus (2) being further configured to:
nin＝(V-V*W*tan(δ)/2L)/2πrin；
nout＝(V+V*W*tan(δ)/2L)/2πrout；
w is the wheel track of the inner side driving wheel (7) and the outer side driving wheel (8), and L is the wheel base of the aerial work platform.
12. A control system for an aerial work platform as claimed in claim 10 wherein the processing apparatus (2) is further configured to:
δ＝k*S+b；
wherein k and b are preset constants.
13. Control system for aerial work platforms according to claim 10, wherein the steering mechanism (5) comprises a telescopic power cylinder, the mechanism displacement S being the extension of the telescopic rod of the telescopic power cylinder.
14. Control system for an aerial work platform according to claim 10, wherein the steering mechanism (5) comprises a displacement sensor for detecting the amount of mechanism displacement S, the processing device (2) being in communication with the displacement sensor and being further configured to be able to acquire the amount of mechanism displacement S from the displacement sensor.
15. A control system for an aerial work platform as claimed in claim 10 wherein the control system further comprises an instruction generating device (1) for generating steering walking instructions to drive the aerial work platform to steer walking, the steering walking instructions comprising walking instructions carrying the vehicle body walking speed V, the processing device (2) being in communication with the instruction generating device (1) and being further configured to be able to extract the vehicle body walking speed V from the walking instructions.
16. A control system for an aerial work platform as claimed in any one of claims 9 to 15 wherein the control system further comprises a visualization device capable of displaying the turn-by-turn walking information.
17. An aerial work platform comprising a control system for an aerial work platform according to any one of claims 9 to 16.
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Application publication date: 20220510 |