CN109335999B - Light carrying trolley - Google Patents

Abstract

The invention discloses a light carrying trolley, relates to a novel lifting scheme of a crane, and is suitable for carrying out efficient lifting and obstacle avoidance carrying on heavy objects under the condition of relatively complex working environment and working conditions. The design of three systems of movement, lifting and clamping realizes the functions of high efficiency and flexible lifting of the crane. The movement of the whole vehicle is realized by means of Mecanum wheels and four-wheel drive, and the efficiency is doubled by two sets of lifting systems arranged on the vehicle head and the vehicle tail. The lifting action is realized by adopting a slide block lead screw mechanism, and the self-locking of the motor can be realized during working. The gear rack mechanism is used for realizing the opening and closing of the hand grab, and the grabbing action of the goods is completed. The hand grab realizes certain expansion in the longitudinal direction, and the tail end is provided with certain convergence, so that the stability and the safety of clamping are ensured. In the aspect of control, the STM32F407 chip and the FLYSKY model airplane remote controller of the Italian semiconductor company are relied on to realize corresponding remote control on the actions of each part of mechanism.

Description

Light carrying trolley

Technical Field

The invention relates to a crane, in particular to a light carrying trolley.

Background

The crane is widely applied to various engineering constructions such as industrial buildings, civil buildings, industrial equipment and the like, and bears the main work of transportation, loading, unloading and installation parts. The method plays an important role in lightening the labor intensity of workers, reducing the construction cost, improving the construction efficiency and improving the construction quality. The types of cranes are various, and the main types of cranes are commonly used: a rubber-tyred crane (truck crane, tire crane), a tower crane, a crawler crane, and the like. The tire type crane has high form speed, can be quickly transferred, but is limited by the chassis, and has a long vehicle body and a large turning radius. The tower crane has high requirements on the site, generally travels on a special wide track, and requires the site to be flat for laying the track, thereby increasing the laying cost. The crawler crane is suitable for rugged places, but the traveling speed is slow, and the damage to the road surface is serious in the traveling process, so that a special vehicle is required for transporting during transferring. Meanwhile, the crawler chassis is heavy and has high manufacturing cost.

In recent years, with the rapid development of the logistics industry, industrial vehicles need to enter places with compact and complex working environments such as warehouses, supermarkets, workshops and the like, so that high requirements on miniaturization, light weight, flexibility and lightness in movement of warehouse logistics transport vehicles are provided. In consideration of the current development situation, the design of the crane-type carrying vehicle is characterized by lightness and flexibility, and the characteristics of the logistics carrying vehicle are combined, so that the novel crane-type carrying vehicle is designed, and the crane-type carrying vehicle plays a positive role in reducing storage pressure and labor cost and improving the transportation efficiency.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and discloses a light carrying trolley, which mainly realizes the functions of high efficiency and flexible lifting of a crane through the design of three mechanical systems of movement, lifting and clamping; and meanwhile, the remote control of the remote control device is realized by combining the singlechip and the model airplane remote controller.

The design idea and strategy of the invention are as follows:

wholly adopt frame construction, under the prerequisite of guaranteeing overall structure's stability, realized the miniaturization and the lightweight of complete machine. Specifically, the first axle and the front axle and the rear axle adopt rectangular aluminum alloy plates to respectively connect Mecanum wheels in pairs; the bottom plate which plays a bearing role is connected with the front and rear bridges by utilizing the aluminum with light weight and strong structural strength; the bottom plate also adopts aluminum alloy plate for the bearing passes through the section aluminium, on front and back bridge evenly distributed to four wheels. And the lifting mechanism adopts a screw rod and a sliding block design, occupies small space, is integrated in the whole product, and also meets the requirements of miniaturization and light weight. And the horizontal clamping mechanism adopts a gear and rack design, occupies small space, is integrated in the whole product, and also meets the requirements of miniaturization and light weight. Fourthly, the clamping mechanism also adopts aluminum alloy with lighter weight as a material on one hand; on the other hand, the hand grip is designed into a strip-shaped structure and is wrapped with plastic foam materials (not shown in the figure) at the periphery so as to increase the friction between the hand grip and the goods and prevent the goods from being damaged. In order to weaken the bending moment of the weight carried by the clamping mechanism, the light weight design of the vehicle is realized, the working performance of the vehicle is considered, the bending moment is digested by the guide rail sliding blocks symmetrically arranged on the left side and the right side, and the product performance is further improved. On the whole, adopt the structural layout mode of front and back symmetry, reasonable high efficiency has utilized installation space, has increased effective dead weight to a certain extent, has increased the chassis, for the steady operation of whole car provides the guarantee, also makes overall structure more compact, provides favorable condition for the miniaturization of design.

In the clamping and carrying strategy, the grabbing (clamping action), stacking (lifting), grabbing (clamping action) and stacking (lifting) are adopted in sequence until the rated load is reached, and then the stack is uniformly clamped and carried away. The vehicle can utilize to rise to utmost and press from both sides to get the action, rises to rise in proper order and pile up neatly with the goods, has increased the bearing capacity of whole car, has promoted work efficiency. The grab has set up a plurality of clamps and has got the height, is applicable to the clamp of co-altitude goods and gets, and mobility is superstrong, has well utilized workspace, has increased once and has come and go the quantity of carrying the goods, has promoted the work efficiency of hoist once more.

In the aspect of controlling the crane, development is carried out based on an MDK development environment by relying on STM32F407ZGT 6. The communication between the remote controller and the crane is realized, and the personal safety of workers is ensured to the maximum extent.

The implementation and further adoption of the technical scheme are as follows:

a light carrying trolley comprises a frame system, a walking system, a lifting system, a grabbing system and a control system;

the frame system comprises a front axle 10, a rear axle 10, a left section aluminum 6 and a right section aluminum 6 which are erected on the front axle 10 and the rear axle 10, and a bottom plate 16 which is arranged on the left section aluminum 6 and the right section aluminum 6;

the traveling system comprises two sets of Mecanum wheels 8, a planetary gear motor 9 and a motor base 4; the motor bases are fixed at the left end side and the right end side of the axle 10 and used for fixing the planetary gear motors and the Mecanum wheels, and each Mecanum wheel is driven by one planetary gear motor to provide walking output for the Mecanum wheel;

the two lifting systems are symmetrically arranged on the base plate 16 from front to back and comprise supporting components, lifting driving motors 2 and lead screw sliding block mechanisms; the supporting component comprises a stepping motor bracket 3, a guide rail 5 and a lifting bracket 17; the lead screw sliding block mechanism comprises a lead screw 1 and a sliding block 7; the guide rail is fixed on the bottom plate 16 and is supported by a lifting bracket, and a lifting driving motor is fixed on the stepping motor bracket; the screw rod is vertically arranged on the stepping motor bracket, and the end part of the screw rod is coaxially arranged with an output shaft of the lifting driving motor, so that the lifting driving motor can drive the screw rod to rotate and further drive the sliding block to lift;

the two grabbing systems are respectively and symmetrically arranged at the head and the tail of the crane;

the whole body is arranged on the sliding block 7 so as to drive the lifting of the grabbing system by the lifting of the sliding block;

each grabbing system comprises a steering engine 15, a gear rack mechanism, a pair of guide rail sliding block mechanisms 18 which are distributed in bilateral symmetry and a hand grab 14; the gear rack mechanism comprises a gear 11 and a rack; the racks comprise an upper rack 13 and a lower rack 12, and the two racks are arranged in parallel up and down; the gear is arranged between the upper rack and the lower rack and is meshed with the upper rack and the lower rack; the gear and a motor of the steering engine are coaxially arranged, and forward and reverse rotation of the steering engine drives the gear to rotate forward and reverse, so that relative motion or reverse motion of the two racks is realized; the hand grab is composed of a pair of left and right grabbing pieces which are respectively positioned at two sides of the gear, and the two grabbing pieces are respectively fixed at the end parts of the two racks and move relatively or reversely along with the racks to realize mutual approaching or separating so as to realize the clamping function; simultaneously, the base of every hand is fixed in and is used for differentiating most bearing in order to weaken rack and pinion mechanism's heavy load on the guide rail slider mechanism to protect rack and pinion mechanism.

The hand grips provide a three-level grip with an inward pinch at each end.

The control part comprises a remote controller, a signal receiver, a main control module, a direct current motor driving module, a steering engine driving module and a stepping motor driving module, wherein the remote controller is used for instruction input, and the input of the main control module is connected with the direct current motor driving module, the steering engine driving module and the stepping motor driving module respectively and is used for controlling the walking state of the chassis mechanism, the action of the hand grasping mechanism and the action of the lifting mechanism.

The invention has the beneficial effects that:

the lifting device is suitable for efficiently lifting heavy objects and avoiding obstacles to carry under the conditions of complex working environment and working conditions. The matching mode of Mecanum wheels and four-wheel drive avoids overlarge turning radius, ensures the flexibility and obstacle avoidance capability of the whole vehicle, and realizes the improvement of the moving capability. Two sets of lifting systems arranged on the head and the tail of the crane ensure one-time lifting weight, fully utilize the flexibility of Mecanum wheels and double the working efficiency of the whole crane. The slider screw mechanism realizes lifting, is favorable for ensuring the stability of lifting and descending, can utilize the self-locking of a motor during working, and can ensure the safety of working to a certain extent. The mode of uniformly carrying stacked goods is adopted, so that the lifting efficiency is further improved. The gear and the rack are matched to realize the clamping action of the grab, so that the grab can be opened and closed greatly, and the clamping of goods is facilitated. Grab in the design, on the one hand, grab and designed three height of grabbing for grab and can grab the goods steadily, prevented that the side direction of goods from empting, guaranteed the stability and the security of work. On the other hand, the tail end of the hand grab is provided with a certain tightening, so that the displacement of the goods is limited, the clamping stability is ensured, and a certain convenient condition is provided for stacking the goods. In the aspect of control, the control of the direct-current speed reduction motor of the crane is realized by controlling the amplitude of a rocker of the remote controller, so that the crane can complete multiple functions of back-and-forth movement, left-and-right translation and clockwise and anticlockwise rotation. Meanwhile, the coupling of the motions can be realized by simultaneously controlling the amplitudes of the rocking bars, so that the flexibility in control is achieved.

Drawings

FIG. 1 is a front view of a light-duty transport cart.

Fig. 2 is a left side view of the light duty floor truck.

FIG. 3 is a top plan view of the light duty tote cart.

Figure 4 is a perspective view of a lightweight carrying cart axle.

Fig. 5 is a control system.

FIG. 6 is an example control system.

Fig. 7 is a software portion in an example of a control system.

Detailed Description

The invention realizes the functions of high efficiency and flexible lifting of the crane through the design of three systems of movement, lifting and clamping. And the movement of the whole vehicle is realized by means of Mecanum wheels and four-wheel drive. Two sets of lifting systems are arranged at the tail of the locomotive, and a sliding block lead screw mechanism is adopted to realize lifting action. The gear rack mechanism is used for realizing the opening and closing of the hand grab, and the grabbing action of the goods is completed. And a control signal is given by a switch and a rocker of the remote controller, so that the crane is controlled.

Mechanical part, as shown in fig. 1 to 4.

A control section, such as the control system shown in fig. 5.

By means of an STM32F407 chip and a FLYSKY model airplane remote controller of the Italian semiconductor company, corresponding remote control over the actions of all parts of mechanisms is achieved. FIG. 6 is an example control system:

in the development of the control program, the following parts are mainly used: the method comprises the following steps of capturing a remote control signal, converting the remote control signal, controlling a chassis direct-current speed reducing motor, controlling a lifting stepping motor and controlling a hand-grasping opening and closing steering engine.

Firstly, after a certain control signal is given, a signal receiver connected to the main control module receives the signal and judges the required action. Then, the main control module decomposes and calculates the signals according to a control program to obtain the corresponding rotating speed and steering signals of the motor, and transmits the rotating speed and steering signals to the corresponding driving module, so that the rotating speed and steering of the motor are controlled, and the expected action is finally completed.

In the design, two rockers (a left rocker controls front-back and left-right translation, a right rocker controls left-right rotation, and upper and lower states) and two switches (RUN is three-position, and FB is two-position) of the FLYSKY model airplane remote controller are used, and six channels are used in total to realize signal transmission. Different switch and rocker amplitude position correspond different high level time, catch rising edge and falling edge through setting up the timer and producing the signal, multiply the count number between rising edge and the falling edge by the time of every count cycle, and then can calculate the time of high level, reflect the position of rocker and switch from this.

The time of the high level captured directly from each channel is a positive integer, which is not beneficial to the subsequent logic judgment and correlation calculation, so after the high level signal is captured, the high level signal needs to be firstly subjected to preliminary linearization processing, and is converted into an interval which is symmetrically distributed about the zero point.

For a chassis direct-current speed reduction motor driving Mecanum wheel, the control is mainly completed by a PWM pulse width speed regulation line, a reversing line and an FG signal line. First, the chassis needs to be coupled for front-back, left-right movement and rotation movement. And respectively controlling the steering of the four Mecanum wheels according to the positive value and the negative value of the numerical value obtained by the steering and the rotation direction coupling of the Mecanum wheels, wherein the positive value corresponds to the positive rotation of the Mecanum wheels, and the negative value corresponds to the negative rotation. And finally, carrying out linear treatment on the numerical values of all the wheels, and converting the numerical values into corresponding 0-3.3V control PWM voltage so as to control the rotating speed of the motor. Because the design has higher requirements on the movement precision of the crane, the rotating speed of the wheel is calculated through the pulse fed back by the FG signal line, and the PI closed-loop control is carried out on the speed.

The control of the lifting stepping motor is mainly divided into two parts. One part is the control of lifting action, and the stepping motor can generate self-locking after being electrified, so that the self-locking is firstly released in the process of controlling the lifting and the descending, and then the positive and negative rotation of the stepping motor is realized through the high and low levels output by the GPIO, thereby realizing the lifting and the descending action. The other part is that in the starting process of the stepping motor, because the load is large, the stepping motor is out of step when being directly started, the adverse effect is generated on the motor, and the control is not facilitated.

The control of the hand-held steering engine realizes that the steering engine reaches different rotation angles mainly through different PWM (pulse width modulation) given values so as to control the opening and closing degree of the hand-held steering engine and control the clamping force.

The control logic is as follows:

	go forward	Retreat	Right translation	Left translation	Rotate	Front lifting	Rear lifting	Front fall	Rear fall	Front clamping	Rear clamping	Anterior relaxation	Post relaxation
														RUN	0	0	0	0	0	1	1	1	1	-1	-1	-1	-1
STATUS	0	0	0	0	0	1	1	-1	-1	1	1	-1	-1
														FB						1	-1	1	-1	1	-1	1	-1

Fig. 7 is a software portion in an example of a control system. A software part:

the receiver receives the remote control signal and transmits the remote control signal to the singlechip. Signals 1/2/3 in the 6 paths of PWM control signals control the chassis to move, and signals 4/5/6 control the clamping and lifting movement.

For chassis movement, the signal is first converted into a symmetrical interval with a zero point as the center for subsequent signal processing. In consideration of the interference of the external environment to the signal, the signal may jump near the zero point, and therefore, a dead zone needs to be set near the zero point to prevent the jitter of the signal. The signals obtained at this time are the integral signals of the vehicle motion, and the signals are required to be decoupled and then coupled to be converted into direction and rotating speed signals of each motor, and finally the signals are output to the motor driving module to drive the motors.

For the clamping movement and the lifting movement, the state quantity of a deflector rod switch is adopted for controlling, so that different intervals need to be converted into corresponding state quantities after signal intervals are converted. And determining the clamping and lifting movement by judging the combination mode of each state quantity.

The invention has the technical characteristics that:

firstly, the Mecanum wheel and four wheels are driven independently, so that the flexibility and the moving capability of the crane are greatly improved, the in-situ steering capability of the crane is particularly endowed, the overlarge turning radius is avoided, the crane can be suitable for severe, complex and narrow working environments, and the realization of the obstacle avoidance function is powerfully guaranteed.

Secondly, two sets of lifting systems are designed at the head and the tail of the crane, so that the effective dead weight is increased, the chassis of the whole crane is enlarged, and the gravity center is always ensured to be within the overturning line of the crane. In the lifting process, the two sets of lifting systems are mutually balanced, so that the lifting mechanism realizes the lifting function and the balancing function. Meanwhile, two sets of lifting systems are adopted, so that the maximum lifting capacity of the crane in one-time reciprocating operation is increased, and the working efficiency is improved. The characteristics of flexible steering of Mecanum wheels are exerted to the maximum extent, and the lifting capacity of the vehicle head and the vehicle tail is ensured.

The invention realizes the work of the crane by adopting a lead screw sliding block and a hand grab clamping mode. The screw rod sliding block mechanism is used as a lifting mechanism, so that the transmission efficiency is high, the friction loss is small, the movement is stable, the possibility of realizing high-speed feeding and micro-feeding is provided, and higher positioning precision can be realized. The goods are clamped and fixed by the hand grab, so that the workload of hoisting work is reduced, and the adverse effects of external factors such as inertia and wind power on the goods are reduced.

Meanwhile, the rack is considered to be of a long and thin structure, the structural stability and the bending resistance of the rack are poor, deformation is easy to occur when the rack is subjected to large bending moment, and adverse effects are brought to the safety and the service life of the whole vehicle. Therefore, a guide rail sliding block mechanism is arranged between the two racks, the hand grab is fixedly connected with the racks and the sliding block, the bending moment applied to the racks is reduced, the movement is more stable and reliable, and the service life is also ensured.

Claims (1)

1. A light carrying trolley is characterized by comprising a frame system, a walking system, a lifting system, a grabbing system and a control system;

the frame system comprises a front axle and a rear axle (10), a left section aluminum and a right section aluminum (6) which are erected on the front axle and the rear axle, and a bottom plate (16) which is arranged on the left section aluminum and the right section aluminum;

the traveling system comprises two sets of Mecanum wheels (8), a planetary gear motor (9) and a motor base (4); the motor bases are fixed at the left end side and the right end side of the axle (10) and used for fixing the planetary gear motors and the Mecanum wheels, and each Mecanum wheel is driven by one planetary gear motor to provide walking output for the Mecanum wheel;

the two lifting systems are symmetrically arranged on the bottom plate (16) from front to back and comprise supporting components, lifting driving motors (2) and screw rod sliding block mechanisms; the supporting component comprises a stepping motor bracket (3), a guide rail (5) and a lifting bracket (17); the lead screw sliding block mechanism comprises a lead screw (1) and a sliding block (7); the guide rail (5) is fixed on the bottom plate (16) and supported by a lifting bracket, and a lifting driving motor is fixed on the stepping motor bracket; the screw rod is vertically arranged on the stepping motor bracket, and the end part of the screw rod is coaxially arranged with an output shaft of the lifting driving motor, so that the lifting driving motor can drive the screw rod to rotate and further drive the sliding block to lift;

the two grabbing systems are respectively and symmetrically arranged at the head and the tail of the crane;

the whole body is arranged on a sliding block (7) so as to drive the lifting of the grabbing system by the lifting of the sliding block;

each grabbing system comprises a steering engine (15), a gear rack mechanism, a pair of guide rail sliding block mechanisms (18) which are distributed in bilateral symmetry and a hand grab (14); the gear rack mechanism comprises a gear (11) and a rack; the racks comprise an upper rack (13) and a lower rack (12), and the two racks are arranged in parallel up and down; the gear is arranged between the upper rack and the lower rack and is meshed with the upper rack and the lower rack; the gear and a motor of the steering engine are coaxially arranged, and forward and reverse rotation of the steering engine drives the gear to rotate forward and reverse, so that relative motion or reverse motion of the two racks is realized; the hand grab is composed of a pair of left and right grabbing pieces which are respectively positioned at two sides of the gear, and the two grabbing pieces are respectively fixed at the end parts of the two racks and move relatively or reversely along with the racks to realize mutual approaching or separating so as to realize the clamping function; meanwhile, the base of each hand grab is fixed on the guide rail sliding block mechanism and is used for dividing most of bearing weight so as to reduce the weight of the gear rack mechanism, thereby protecting the gear rack mechanism;

the control system comprises a remote controller, a signal receiver, a main control module, a direct current motor driving module, a steering engine driving module and a stepping motor driving module, wherein the remote controller is used for instruction input and is connected with the main control module through the signal receiver; the input of the main control module is respectively connected with the direct current motor driving module, the steering engine driving module and the stepping motor driving module and used for controlling the walking state of the chassis mechanism, the action of the hand grasping mechanism and the action of the lifting mechanism;

the main control module comprises the following steps of capturing a remote control signal, converting the remote control signal, controlling a chassis direct-current speed reducing motor, controlling a lifting stepping motor and controlling a hand-grasping opening and closing steering engine, and further comprises an algorithm process:

firstly, after a certain control signal is given, a signal receiver connected to a main control module receives the signal and judges a required action; then, the main control module decomposes and calculates the signals according to a control program to obtain the corresponding rotating speed and steering signals of the motor, and transmits the rotating speed and steering signals to the corresponding driving module, so that the rotating speed and steering of the motor are controlled, and the expected action is finally finished;

the method comprises the following steps of (1) using two rockers, two switches and six channels of the FLYSKY model airplane remote controller to realize signal transmission; different switch and rocker amplitude positions correspond to different high level time, the timer is set, the rising edge and the falling edge of a generated signal are captured, the counting number between the rising edge and the falling edge is multiplied by the time of each counting period, and then the high level time is calculated, so that the positions of the rocker and the switch are reflected;

for a chassis direct-current speed reduction motor to drive Mecanum wheels, the control of the Mecanum wheels is mainly completed by a PWM pulse width speed regulation line, a reversing line and an FG signal line; firstly, coupling front, back, left and right movement and rotation movement of a chassis; respectively controlling the steering of the four Mecanum wheels according to the positive value and the negative value of the numerical value obtained by the steering and the rotation direction coupling of the Mecanum wheels, wherein the positive value corresponds to the positive rotation of the Mecanum wheels, and the negative value corresponds to the negative rotation; finally, carrying out linear treatment on the numerical values of all the wheels, and converting the numerical values into corresponding 0-3.3V control PWM voltage so as to control the rotating speed of the motor; the rotating speed of the wheel is calculated through the pulse fed back by an FG signal line, and PI closed-loop control is carried out on the speed;

the control of the lifting stepping motor is divided into two parts, one part is the control of lifting action, the stepping motor can generate self-locking after being electrified, in the process of controlling lifting and descending, the self-locking is firstly released, and then the positive and negative rotation of the stepping motor is realized through the high and low level output by the GPIO, so that the lifting and descending actions are realized; the other part is that in the starting process of the stepping motor, a linear acceleration is given to the stepping motor in the starting stage;

the control of the steering wheel is grabbed in hand then mainly through different PWM given values, realizes that the steering wheel reaches different rotation angles to this opening and shutting degree of controlling to grab in hand, in order to realize the control to clamping force, control logic is as follows:

go forward Retreat Right translation Left translation Rotate Front lifting Rear lifting Front fall Rear fall Front clamping Rear clamping Anterior relaxation Post relaxation RUN 0 0 0 0 0 1 1 1 1 -1 -1 -1 -1 STATUS 0 0 0 0 0 1 1 -1 -1 1 1 -1 -1 FB 1 -1 1 -1 1 -1 1 -1

After receiving the remote control signal, the receiver transmits the remote control signal to the single chip microcomputer, a signal 1/2/3 in the 6 paths of PWM control signals controls the chassis to move, and a signal 4/5/6 controls the clamping and lifting movement;

for the chassis movement, firstly, signals are converted into symmetrical intervals with a zero point as a center, and a dead zone is set near the zero point; decoupling and recoupling the signals to convert the signals into direction and rotating speed signals of each motor, and finally outputting the signals to a motor driving module to drive the motors;

for the clamping movement and the lifting movement, the state quantity of a deflector rod switch is adopted for controlling, and after signal intervals are converted, different intervals need to be converted into corresponding state quantities; and determining the clamping and lifting movement by judging the combination mode of each state quantity.

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