CN111776990A

CN111776990A - Unmanned carrying automatic guided vehicle and guiding method thereof

Info

Publication number: CN111776990A
Application number: CN202010652614.3A
Authority: CN
Inventors: 谷亚运; 姚志坚; 尹道骏
Original assignee: Hefei Jingsong Intelligent Technology Co Ltd
Current assignee: Hefei Jingsong Intelligent Technology Co Ltd
Priority date: 2020-07-08
Filing date: 2020-07-08
Publication date: 2020-10-16
Also published as: CN214734180U

Abstract

The invention discloses an automatic guided vehicle for unmanned transport and a guiding method thereof. The automatic guided vehicle comprises a vehicle body, two fork legs, two driving wheel mechanisms, a driven wheel mechanism, a hydraulic system and a covering fork. Each driving wheel mechanism is arranged in the corresponding fork leg and comprises a servo motor, a driving wheel, a bevel gear set, a driving shaft and a fixing plate. The servo motor drives the driving shaft to rotate through the bevel gear set, and an output shaft of the servo motor is perpendicular to the driving shaft. The driving shaft is rotatably mounted on the fixing plate, and the fixing plate is fixed on the corresponding fork leg. The driven wheel mechanism is arranged in the vehicle body and comprises two driven wheels, a rotating frame, a rotating shaft and a first fixed seat. The hydraulic system comprises a pump station, a synchronous valve and two jacking devices. The automatic guided vehicle can not move when being lifted, so that the goods can be lifted stably, the goods are prevented from shaking, the carrying stability can be improved, the overall size of the AGV is reduced, and the navigation precision is improved.

Description

Unmanned carrying automatic guided vehicle and guiding method thereof

Technical Field

The invention relates to an automatic guided vehicle in the technical field of transport vehicles, in particular to an unmanned automatic guided vehicle and a guiding method of the unmanned automatic guided vehicle.

Background

An AGV (automatic guided vehicle) is an unmanned automatic carrying vehicle which takes a battery as power and is provided with a non-contact guiding device and an independent addressing system. The industrial application does not need a driver's transport vehicle, and a rechargeable storage battery is used as a power source of the industrial application. Generally, the traveling path and behavior can be controlled by a computer, or the traveling path can be established by using an electromagnetic rail, the electromagnetic rail is adhered to the floor, and the unmanned transport vehicle moves and acts by means of information brought by the electromagnetic rail.

Wherein tray formula AGV uses extensively, can be used to various fields such as tray pallet transport, material handling, material letter sorting, and traditional fork truck formula tray AGV is bulky, and turning radius is big, and unsuitable intensive storage area, and the lift of fork leg is realized through the connecting rod transmission, and the automobile body can rock when fork leg goes up and down, influences the positioning accuracy of navigation. Moreover, some slipping phenomena easily occur in the forklift type tray AGV due to ground reasons.

Disclosure of Invention

The invention provides an unmanned automatic guided vehicle and a guiding method thereof, aiming at solving the technical problems that the existing automatic guided vehicle is easy to slip and has poor stability.

The invention is realized by adopting the following technical scheme: an unmanned automated guided vehicle, comprising:

a vehicle body;

the two fork legs are arranged in parallel, and the same end of the two fork legs is arranged on the same side of the vehicle body;

two driving wheel mechanisms respectively corresponding to the two fork legs, each driving wheel mechanism being mounted in the corresponding fork leg; each driving wheel mechanism comprises a servo motor, a driving wheel, a bevel gear set, a driving shaft and a fixing plate; the servo motor is used for driving the driving shaft to rotate through the bevel gear set, and an output shaft of the servo motor is perpendicular to the driving shaft; the driving wheels are sleeved on the corresponding driving shafts, and the two driving wheels form two fulcrums I; the driving shaft is rotatably arranged on the fixing plate, and the fixing plate is fixed on the corresponding fork leg;

a driven wheel mechanism mounted in the vehicle body; the driven wheel mechanism comprises at least two driven wheels, a rotating frame, a rotating shaft and a first fixed seat; the first fixed seat is fixed on the vehicle body and is rotatably mounted on the rotating frame through the rotating shaft; the two driven wheels are respectively arranged at two opposite ends of the rotating frame, can rotate around the rotating shaft and form a second fulcrum; the two first fulcrums and the second fulcrums form a three-fulcrum structure of the automatic guided vehicle;

the hydraulic system comprises a pump station, a synchronous valve and two jacking devices; the pump station is arranged on the vehicle body and used for providing hydraulic oil for the synchronous valve; the two jacking devices are respectively arranged in the two supporting legs, and each jacking device provides at least two synchronous jacking ends; the synchronous valve is arranged on the vehicle body and is used for driving the synchronous jacking ends of the two jacking devices to synchronously lift; and

and the covering fork is fixed on the synchronous jacking ends, and the top of the covering fork is provided with at least one load surface.

The servo motors of the two driving wheel mechanisms respectively drive the corresponding bevel gear sets to rotate so as to drive the driving wheels to rotate, the two driving wheels form a first supporting point, and the two driven wheels rotate around the rotating shaft so as to form a second supporting point, so that the three supporting points form a three-supporting-point structure, the two driving wheels are ensured to land all the time, the positive pressure with the ground is synchronously increased along with the increase of the load, and the driving wheels are also ensured not to slip due to insufficient friction force. The pump station of the hydraulic system drives the jacking devices to ascend and descend through the synchronous valves, the two jacking devices are enabled to ascend and descend synchronously, the vehicle body cannot move during ascending and descending, the goods can ascend and descend stably, and the goods are prevented from shaking. In addition, the driving wheel mechanism and the jacking device are arranged in the fork legs, and the driven wheel mechanism is arranged in the vehicle body, so that the size of the automatic guided vehicle can be reduced, and the automatic guided vehicle is more miniature. Therefore, the invention solves the technical problems of easy slipping and poor stability of the existing automatic guided vehicle, and obtains the technical effects of good stability, difficult slipping, more mini size and capability of meeting various carrying requirements.

As a further improvement of the above scheme, each jacking device comprises an oil cylinder, a second fixed seat, at least two jacking mechanisms and at least one connecting rod; the second fixing seat is fixed in the fork leg; the oil cylinder is arranged on the second fixed seat, receives the hydraulic oil distributed by the synchronous valve and is used for driving one of the jacking mechanisms to do lifting action; the two ends of each connecting rod are respectively connected with the lifting ends of two adjacent jacking mechanisms, and the lifting ends of the jacking mechanisms are the synchronous jacking ends.

Furthermore, each jacking mechanism comprises two upper jacking trough plates, two lower jacking trough plates, four rotating plates, a front fixed plate, a rear fixed plate, a return spring, a jacking plate, a jacking connecting plate, two rotating shafts and two sliding shafts; the front fixing plate and the rear fixing plate are fixed on the fork legs and are separated to form a first mounting space; the two lower jacking groove plates are arranged in the first installation space and separated to form a second installation space; two ends of each lower jacking trough plate are respectively fixed on the front fixing plate and the rear fixing plate and provided with a first circular through hole and a first horizontal waist hole; one rotating shaft penetrates through the first two round through holes, and one sliding shaft penetrates through the first two horizontal waist holes; each upper jacking trough plate is positioned above one lower jacking trough plate and is provided with a circular through hole II and a horizontal waist hole II; the two upper jacking groove plates are connected through the jacking connecting plate; the other rotating shaft penetrates through the two circular through holes II, and the other sliding shaft penetrates through the two horizontal waist holes II; the middle parts of the two rotating plates are rotatably connected, and the end parts of the two rotating plates are respectively sleeved on the same ends of the two rotating shafts and the two sliding shafts to form a group of single-piece scissors fork; the middle parts of the other two rotating plates are rotatably connected, and the end parts of the other two rotating plates are respectively sleeved on the same other ends of the two rotating shafts and the two sliding shafts to form another group of single-piece scissors fork; one end of the reset spring is fixed on the front fixing plate, and the other end of the reset spring is fixed on the jacking plate; the jacking plate is fixed with the sliding shaft positioned on the lower side, and the oil cylinder is used for pushing and pulling the corresponding jacking plate of the jacking mechanism.

As a further improvement of the above solution, the automated guided vehicle further comprises:

the electronic control system is arranged in the vehicle body and comprises a navigator and a control unit; the navigator is mounted on the top of the vehicle body and used for navigating; the control unit is used for controlling the driving wheel mechanism, the hydraulic system and the navigator.

Further, the electric control system also comprises a lithium battery; the lithium battery is installed on the vehicle body and used for supplying power to the control unit, the driving wheel mechanism, the hydraulic system and the navigator.

Still further, the electric control system also comprises at least two collision sensors and a collision prevention contact edge; wherein at least one impact sensor is mounted on the front end of the fork leg, wherein at least another impact sensor is mounted on the rear of the vehicle body; the collision sensor is used for emitting laser and determining the distance between the collision sensor and an object in the laser irradiation direction according to the laser return time; the control unit is used for judging whether the distance is smaller than a set threshold value or not; when the distance is smaller than the set threshold value, the control unit drives the driving wheel mechanism to stop acting; the anti-collision contact edge is arranged on the rear part of the vehicle body and is of an elastic structure; wherein the lithium battery is further used for supplying power to the collision sensor.

Further, the electric control system also comprises a power switch, an emergency stop switch and two drivers; the power switch is used for turning on or off the lithium battery; the emergency stop switch is an emergency stop structure of the automatic guided vehicle; the two drivers are respectively used for controlling servo motors of the two driving wheel mechanisms.

As a further improvement of the above solution, the bevel gear set comprises a driving spiral bevel gear and a driven spiral bevel gear which are meshed with each other; the servo motor is used for driving the driving spiral bevel gear to rotate; the driven spiral bevel gear is sleeved on the driving shaft.

Still further, each driving wheel mechanism also comprises a speed reducer; the output shaft of the servo motor is connected with the input end of the speed reducer, and the driving spiral bevel gear is sleeved on the output end of the speed reducer

The invention also provides a guiding method of the unmanned automatic guided vehicle, which comprises the following steps:

two driving wheels form a first fulcrum, and two driven wheels rotate around the rotating shaft to form a second fulcrum, so that the first fulcrum and the second fulcrum form a three-fulcrum structure of the automatic guided vehicle;

driving wheels of the two driving wheel mechanisms to rotate; the two fork legs synchronously move through the two first fulcrums, and the vehicle body synchronously moves along with the two fork legs through the second fulcrums;

through the pump station control the feed liquor volume of synchronizing valve, synchronizing valve orders about two jacking devices synchronous lift corresponding synchronous jacking end, makes the jacking of covering fork is located load on the load face.

Compared with the existing automatic guided vehicle, the unmanned automatic guided vehicle and the guiding method thereof have the following beneficial effects:

1. according to the unmanned carrying automatic guided vehicle, servo motors of two driving wheel mechanisms respectively drive corresponding bevel gear sets to rotate so as to drive the driving wheels to rotate, the two driving wheels form a first supporting point, two driven wheels rotate around a rotating shaft to form a second supporting point, so that the three supporting points form a three-supporting-point structure, the two driving wheels are guaranteed to land all the time, the positive pressure of the two driving wheels and the positive pressure of the ground can be synchronously increased along with the increase of the load, the driving wheels are also guaranteed not to slip due to insufficient friction force, and the transportation of goods or materials is enabled to be more stable. The pump station of the hydraulic system drives the jacking devices to ascend and descend through the synchronous valves, the two jacking devices are synchronously ascended and descended, the vehicle body cannot move during ascending and descending, the goods can stably ascend and descend, the goods are prevented from shaking, and the carrying stability can be improved. And, set up driving wheel mechanism and jacking device in the fork leg, set up driven wheel mechanism in the automobile body, just so can reduce automated guided vehicle's volume, make automated guided vehicle more mini, can satisfy various transport demands.

2. The driving wheel mechanisms 3 are arranged in the two fork legs on one side of the unmanned automatic guided vehicle, the two servo motors drive the two driving wheels to rotate, the automatic guided vehicle can move forwards and backwards when the two driving wheels rotate in the same direction and at the same speed, and the automatic guided vehicle can turn when the two driving wheels rotate in the same speed or at different speeds, so that the AGV can be controlled to operate by controlling the rotating speeds of the two driving wheels. In addition, the driving wheel mechanism is arranged in the fork legs, so that the size of the car body is reduced, the overall size of the AGV is reduced, the AGV is driven by a traditional single steering wheel to be changed into double wheels, and the navigation precision is improved. And the driving wheel mechanism is driven by the spiral bevel gear, and compared with chain transmission, the driving wheel mechanism does not need tensioning, is simple to mount and has higher transmission precision.

3. According to the unmanned carrying automatic guided vehicle, the lifting principle of the jacking mechanism in each jacking device of the hydraulic system is the scissor fork jacking principle, the upper jacking groove plate, the lower jacking groove plate and the two rotating plates are connected through shafts to form a single scissor fork, so that the vertical lifting movement of the jacking mechanism can be realized, and the lifting is more stable. And because the horizontal movement displacement of the two jacking mechanisms is far smaller than the vertical movement position, the lifting amount of a larger stroke can be completed by using an oil cylinder with a smaller stroke, and the oil cylinder has a maximum stroke and a minimum stroke position which correspond to the highest position and the lowest position of the jacking mechanisms, so that the position where the fork stops is accurate and stable, and the high position and the low position are easier to be judged through photoelectric capture.

4. According to the unmanned automatic guided vehicle, the jacking mechanism of the jacking device in the hydraulic system is provided with the return spring, the oil cylinder is a single-acting cylinder, the risk of unsmooth falling and blocking exists when the oil cylinder is jacked to the maximum position and falls back, the return spring always provides thrust for the oil cylinder, the falling process is smoother, and no risk is caused when the oil cylinder is blocked.

5. The two jacking mechanisms in each fork leg of the unmanned automatic guided vehicle are fixedly connected through the connecting rod, so that the two jacking mechanisms act synchronously, and meanwhile, the four jacking mechanisms are integrally connected and fixed through the covering forks. The jacking uses the principle of the scissor fork jacking, and the action area of the jacked upper jacking trough plate is large, so that the covering fork cannot deform due to load. The two oil flows are synchronized through the synchronizing valve, so that the two oil cylinder pistons have the same speed, and the speed difference caused by different loads can be avoided. Therefore, the three points are multiple, so that the fork is vertically and horizontally moved upwards when the automatic guided vehicle takes the goods, the goods cannot shake, and the goods taking is more stable.

6. The beneficial effect of the guiding method is the same as that of the unmanned automatic guided vehicle, and the description thereof is omitted.

Drawings

Fig. 1 is a schematic perspective view of an automated guided vehicle for unmanned transport according to embodiment 1 of the present invention.

Fig. 2 is a plan view of a drive wheel mechanism of the automated guided vehicle for unmanned transport in fig. 1.

Fig. 3 is a schematic perspective view of a driven wheel mechanism of the automated guided vehicle in fig. 1.

Fig. 4 is a schematic perspective view of a hydraulic system of the automated guided vehicle in fig. 1.

Fig. 5 is a schematic perspective view of the jacking device of the automated guided vehicle in fig. 1.

Fig. 6 is a schematic perspective view of a jacking mechanism of the jacking device of the automated guided vehicle in fig. 1.

Fig. 7 is a schematic perspective view of an electric control system of the automated guided vehicle for unmanned transportation in fig. 1.

Description of the symbols:

1 vehicle body 55 synchronous valve

2-fork leg 70 navigator

3 drive wheel mechanism 71 control unit

4 driven wheel mechanism 72 lithium cell

5 Hydraulic system 73 driver

31 servo motor 75 collision sensor

32 speed reducer 76 anticollision is touched limit

33 driving wheel 77 power switch

34 active spiral bevel gear 78 emergency stop switch

35 driven spiral bevel gear 511 oil cylinder

36 driving shaft 512 fixed seat two

37 fixed plate 520 upper jacking trough plate

41 driven wheel 521 lower jacking trough plate

42 rotating frame 522 rotating plate

43 rotating shaft 523 front fixed plate

44 fixed seat 524 rear fixing plate

Reset spring of 51-power jacking mechanism 525

52 driven jacking mechanism 526 jacking plate

53 connecting rod 527 jacking connecting plate

54 pumping station

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

Referring to fig. 1-7, the present embodiment provides an automated guided vehicle, which may be referred to as a mini-Automated Guided Vehicle (AGV), for transporting goods or materials without driving. The unmanned automatic guided vehicle comprises a vehicle body 1, fork legs 2, a driving wheel mechanism 3, a driven wheel mechanism 4, a hydraulic system 5 and an electric control system.

The vehicle body 1 is a main body part of the automated guided vehicle, and in the present embodiment, the vehicle body 1 is a housing structure in which other parts can be mounted. The car body 1 can be the car body 1 of the existing AGV, and the specific size and shape of the car body 1 can be set according to actual needs. The periphery of the vehicle body 1 can be rounded, so that the vehicle body 1 can be prevented from colliding with other objects in the driving process and being damaged. The surface of the vehicle body 1 may be coated with a wear-resistant material or may be coated with other materials.

The number of the fork legs 2 is two, the two fork legs 2 are arranged in parallel, and the same end is arranged on the same side of the vehicle body 1. The front end of the fork leg 2 is a tip end, and the rear end of the fork leg 2 is positioned outside the same side of the vehicle body 1 and is arranged on the bottom of the same side of the vehicle body 1. The fork leg 2 can be made of the existing fork leg 2 material, and the length of the fork leg can be designed according to actual needs. The function of the fork legs 2 is the same as that of the fork legs 2 of the existing AGV, and the goods or materials can be jacked up, so that the goods can be conveniently put down or lifted.

With continued reference to fig. 2, the number of the driving wheel mechanisms 3 is two, and two driving wheel mechanisms 3 correspond to two fork legs 2 respectively. Each drive wheel mechanism is mounted in a corresponding fork leg 2 and each drive wheel mechanism 3 comprises a servo motor 31, a reducer 32, a drive wheel 33, a bevel gear set, a drive shaft 36 and a fixed plate 37. The servo motor 31 is used for driving the driving shaft 36 to rotate through the bevel gear set, and the output shaft of the servo motor 31 is perpendicular to the driving shaft 36. The driving wheels 33 are sleeved on the corresponding driving shafts 36, and the two driving wheels 33 form two supporting points I. The drive shaft 36 is rotatably mounted on a fixed plate 37, which fixed plate 37 is fixed to the corresponding fork leg 2. In this embodiment, the bevel gear set includes a driving spiral bevel gear 34 and a driven spiral bevel gear 35, and the driving spiral bevel gear 34 and the driven spiral bevel gear 35 are engaged with each other. The driven spiral bevel gear 35, the drive wheel 33 and the drive shaft 36 are keyed. The servo motor 31 is used for driving the driving spiral bevel gear 34 to rotate, and the driven spiral bevel gear 35 is sleeved on the driving shaft 36. The output shaft of the servo motor 31 is connected with the input end of the speed reducer 32, and the driving spiral bevel gear 34 is sleeved on the output end of the speed reducer 32.

The driving wheel mechanisms 3 are arranged in the two fork legs 2 on one side of the vehicle body 1, the two servo motors 31 drive the two driving wheels 33 to rotate, when the two driving wheels 33 rotate in the same direction and at the same speed, the AGV can move forwards and backwards, and when the two driving wheels 33 rotate in the opposite direction or are at a differential speed, the AGV can turn, so that the AGV can be controlled to operate by controlling the rotating speed of the two driving wheels 33. Through placing drive wheel mechanism 3 in fork leg 2, reduced automobile body 1's size on the one hand, reduced AGV's overall dimension, on the other hand AGV is become double round drive by traditional single steering wheel drive, has promoted the navigation accuracy. The driving wheel mechanism 3 is driven by the spiral bevel gear, and compared with chain transmission, tensioning is not needed, the installation is simple, and the transmission precision is higher. The position of installing drive wheel mechanism 3 on fork leg 2 cuts the notch, and drive wheel mechanism 3 is the fixed mounting of embedded notch intraoral, has guaranteed the transmission stability of drive wheel mechanism 3 when AGV moves, can not produce the removal. In this embodiment, AGV's cover fork ground clearance is 90mm, and the length of fork 1150 mm.

With reference to fig. 3, the driven wheel mechanism 4 is installed in the vehicle body 1 and includes a driven wheel 41, a rotating frame 42, a rotating shaft 43 and a first fixing seat 44. The first fixing seat 44 is fixed on the vehicle body 1 and is rotatably mounted on the rotating frame 42 through the rotating shaft 43. The number of the driven pulleys 41 is at least two, and the two driven pulleys 41 are respectively installed on the opposite ends of the rotating frame 42, can rotate around the rotating shaft 43 and form a second pivot. The two first fulcrums and the second fulcrums form a three-fulcrum structure of the automatic guided vehicle. The three-pivot structure can ensure that the two driving wheels 33 are always grounded, the positive pressure with the ground is synchronously increased along with the increase of the load, and the driving wheels 33 cannot slip due to insufficient friction force.

With continued reference to fig. 4, 5 and 6, the hydraulic system 5 includes a pumping station 54, a synchronizing valve 55 and two jacking devices. A pump station 54 is mounted on the vehicle body 1 and is used to supply hydraulic oil to the synchronizing valve 55. Two jacking devices are installed respectively in two landing legs, and every jacking device provides two at least synchronous jacking ends. The synchronous valve 55 is installed on the vehicle body 1 and used for driving synchronous lifting ends of the two lifting devices to lift synchronously. Because two jacking devices are located inside two fork legs 2 respectively, have reduced automobile body 1's space, make AGV overall structure compacter, the volume is littleer.

In this embodiment, each jacking device includes an oil cylinder 511, a second fixed seat 512, a jacking mechanism, and a connecting rod 53. The second fixed seat 512 is fixed in the fork leg 2. In this embodiment, the number of the jacking mechanisms is at least two, the two jacking mechanisms are respectively a power jacking mechanism 51 and a driven jacking mechanism 52, the power jacking mechanism 51 is one close to the oil cylinder 511, and the driven jacking mechanism 52 is one far from the oil cylinder 511. And the number of connecting rod 53 is at least one, and a connecting rod 53 is arranged between two adjacent jacking mechanisms. The oil cylinder 511 is installed on the second fixed seat 512, receives the hydraulic oil distributed by the synchronous valve 55, and is used for driving one of the jacking mechanisms to do lifting motion. The two ends of each connecting rod 53 are respectively connected with the lifting ends of two adjacent jacking mechanisms, and the lifting ends of the jacking mechanisms are synchronous jacking ends.

Each jacking mechanism comprises two upper jacking groove plates 520, two lower jacking groove plates 521, four rotating plates 522, a front fixed plate 523, a rear fixed plate 524, a return spring 525, a jacking plate 526, a jacking connecting plate 527, a rolling bearing, two rotating shafts and two sliding shafts. The front fixing plate 523 and the rear fixing plate 524 are fixed on the fork leg 2 and separated by a first installation space. Two lower jacking slot plates 521 are arranged in the first installation space and separated by a second installation space. Two ends of each lower jacking slot plate 521 are respectively fixed on the front fixing plate 523 and the rear fixing plate 524, and a circular through hole I and a horizontal waist hole I are formed. One rotating shaft penetrates through the first two circular through holes, and one sliding shaft penetrates through the first two horizontal waist holes. Each upper jacking trough plate 520 is positioned above one lower jacking trough plate 521 and is provided with a second circular through hole and a second horizontal waist hole. The two upper jacking slot plates 520 are connected through a jacking connecting plate 527. The other rotating shaft penetrates through the two circular through holes II, and the other sliding shaft penetrates through the two horizontal waist holes II. The middle parts of the two rotating plates 522 are rotatably connected, and the end parts of the two rotating plates are respectively sleeved on the same ends of the two rotating shafts and the two sliding shafts to form a group of single-piece scissors fork. The middle parts of the other two rotating plates 522 are rotatably connected, and the end parts of the other two rotating plates are respectively sleeved on the same other ends of the two rotating shafts and the two sliding shafts to form another group of single-piece scissors. One end of the return spring 525 is fixed to the front fixing plate 523, and the other end is fixed to the lift plate 526. The lift plate 526 is fixed to a slide shaft located on the lower side, and the oil cylinder 511 is used to push and pull the lift plate 526 of the corresponding lift mechanism. Because the oil cylinder 511 is a single-acting cylinder, the risk of unsmooth falling and blocking exists when the oil cylinder is jacked to the maximum position and falls back, and the return spring 525 always provides thrust for the oil cylinder 511, so that the falling back process is smoother, and no risk is caused by blocking.

The two single scissors forks are fixed between a front fixed plate 523 and a rear fixed plate 524, and the two lifting groove plates 520 are connected and fixed through a lifting connecting plate 527 to form a scissors fork lifting mechanism. The jacking plate 526, the lower jacking trough plate 521, the rotating plate 522 and the rolling bearing are connected through a whole shaft, the jacking plate 526 is pushed to enable the bearings in the upper jacking trough plate 520 and the lower jacking trough plate 521 to horizontally roll at the same time, and vertical lifting movement of the driven jacking mechanism 52 can be achieved. The power jacking mechanism 51 and the driven jacking mechanism 52 are vertically lifted, so that the lifting is more stable. The horizontal movement displacement of the power jacking mechanism 51 and the driven jacking mechanism 52 is far smaller than the vertical movement position, the oil cylinder 511 with a small stroke can be used for completing the lifting amount of a large stroke, the oil cylinder 511 has a maximum stroke and a minimum stroke position, and corresponds to the highest position and the lowest position of the driven jacking mechanism 52, so that the fork stopping position is accurate and stable, and the high position and the low position are easier to be judged through photoelectric capture.

In this embodiment, the hydraulic jacking principle is that hydraulic oil is fed into the synchronizing valve 55 by the pump station 54, one of the synchronizing valve 55 is fed into and fed out from the other, two outlets are connected with the two oil cylinders 511, so that the hydraulic oil flows into the two oil cylinders 511 to perform piston movement, and a piston rod is inserted into the jacking plate 526 and fixed by a bolt, so as to push the jacking plate 526 to perform horizontal movement, so that bearings in the upper jacking trough plate 520 and the lower jacking trough plate 521 roll horizontally at the same time, thereby realizing vertical lifting of the driven jacking mechanism 52, and meanwhile, the power jacking mechanism 51 in a single fork leg 2 and the jacking plate 526 in the driven jacking mechanism 52 are fixed by a connecting rod 53, so that the power jacking mechanism 51 and the driven jacking mechanism 52 operate synchronously, and the covering fork is fixed on the upper jacking trough plate 520 by a bolt, so that the lifting of the covering fork can be driven by the lifting mechanism 51, thereby. On the contrary, the oil return port of the pump station 54 is opened by control, the hydraulic oil in the oil cylinder 511 flows back to the oil tank under the action of the gravity of the covering fork and the thrust of the return spring 525, and the four sets of driven jacking mechanisms 52 descend to the lowest position, namely the pallet fork falls to the lowest position. In the above technical scheme, the power jacking mechanism 51 and the driven jacking mechanism 52 in each fork leg 2 are fixedly connected through the connecting rod 53, so that the power jacking mechanism 51 and the driven jacking mechanism 52 act synchronously, and meanwhile, the two groups of power jacking mechanisms 51 and the two groups of driven jacking mechanisms 52 are connected and fixed into a whole through the covering forks.

The lifting principle of the driven lifting mechanism 52 is a scissor fork lifting principle, and because the upper lifting slotted plate 520, the lower lifting slotted plate 521 and the two rotating plates 522 are connected through shafts to form a single scissor fork, wherein one end of the connecting part of the upper lifting slotted plate 520, the lower lifting slotted plate 521 and the rotating plates 522 is connected with the shafts to be rotatable and non-rollable, and the other end of the connecting part of the rotating plates 522 is connected with a bearing to be rolled in a slot on the lifting plate 526. Two sets of single scissors forks are fixed between a front fixing plate 523 and a rear fixing plate 524, and the upper jacking trough plates 520 are connected and fixed through jacking connecting plates 527 to form a scissors fork jacking mechanism. The jacking uses the principle of scissor fork jacking, and the action area of the jacked upper jacking trough plate 520 is large, so that the covering fork cannot deform due to load; the two oil cylinders 511 synchronize flow through the synchronization valve 55, so that the piston speeds of the two oil cylinders 511 are the same, and the speed difference caused by different loads can be avoided; the three points are multiple, so that the fork is vertically and horizontally moved upwards when the AGV fetches the goods, the goods cannot shake, and the goods fetching is more stable.

Referring to fig. 7, the electronic control system is disposed in the vehicle body 1 and includes a navigator 70, a control unit 71, a lithium battery 72, a collision sensor 75, a collision prevention edge 76, a power switch 77, an emergency stop switch 78, and a driver 73. The navigator 70 is mounted on the top of the vehicle body 1 and is used for navigation. Those skilled in the art can also apply the automatic navigation system in the prior art to the present system. The control unit 71 is used for controlling the driving wheel mechanism 3, the hydraulic system 5 and the navigator 70, and can also control other mechanisms or components, that is, the information of all electrical components is reported to the control unit 71 for processing. The lithium battery 72 is mounted on the vehicle body 1 and is used to supply power to the control unit 71, the drive wheel mechanism 3, the hydraulic system 5, and the navigator 70, and also to supply power to the collision sensor 75, the driver 73.

The number of the collision sensors 75 is at least two, at least one of which 75 is mounted on the front end of the fork leg 2, and at least another one of which 75 is mounted on the rear portion of the vehicle body 1. The collision sensor 75 is configured to emit laser light, and determine the distance to the object in the laser light irradiation direction based on the laser light return time. The bump guard 76 is mounted on the rear portion of the vehicle body 1 and is of a resilient construction. The lithium battery 72 is also used to supply power to the collision sensor 75, among other things. The power switch 77 is used to turn on or off the lithium battery 72, and the emergency stop switch 78 is an emergency stop structure of the automated guided vehicle. The two drivers 73 are used to control the servo motors 31 of the two drive wheel mechanisms 3, respectively.

In summary, compared with the existing automated guided vehicle, the automated guided vehicle for unmanned transportation of the embodiment has the following advantages:

1. according to the unmanned automatic guided vehicle, the servo motors 31 of the two driving wheel mechanisms 3 respectively drive the corresponding bevel gear sets to rotate so as to drive the driving wheels 33 to rotate, the two driving wheels 33 form a first supporting point, the two driven wheels 41 rotate around the rotating shaft 43 to form a second supporting point, and thus the three supporting points form a three-supporting-point structure, so that the two driving wheels 33 are guaranteed to land all the time, the positive pressure of the two driving wheels 33 and the ground is synchronously increased along with the increase of the load, and meanwhile, the driving wheels 33 are guaranteed not to slip due to insufficient friction force, so that the transportation of goods or materials is more stable. The pump station 54 of the hydraulic system 5 drives the jacking devices to lift through the synchronous valve 55, and the two jacking devices are lifted synchronously, so that the vehicle body 1 cannot move during lifting, the goods can lift stably, the goods are prevented from shaking, and the carrying stability can be improved. Moreover, the driving wheel mechanism 3 and the jacking device are arranged in the fork legs 2, and the driven wheel mechanism 4 is arranged in the vehicle body 1, so that the volume of the automatic guided vehicle can be reduced, the automatic guided vehicle is more miniature, and various carrying requirements can be met.

2. According to the unmanned automatic guided vehicle, the two fork legs 2 on one side of the vehicle body 1 are internally provided with the driving wheel mechanisms 33, the two servo motors 31 drive the two driving wheels 33 to rotate, the automatic guided vehicle can move forwards and backwards when the two driving wheels 33 rotate in the same direction at the same speed, and the automatic guided vehicle can steer when the two driving wheels 33 rotate in the same speed or at different speeds, so that the AGV can be controlled to run by controlling the rotating speed of the two driving wheels 33. In addition, according to the automatic guided vehicle, the driving wheel mechanism 3 is placed in the fork legs 2, so that the size of the vehicle body 1 is reduced, the overall size of the AGV is reduced, the AGV is driven by a traditional single steering wheel to be changed into double-wheel driving, and the navigation precision is improved. Moreover, the driving wheel mechanism 3 is driven by the spiral bevel gear, and compared with chain transmission, tensioning is not needed, the installation is simple, and the transmission precision is higher.

3. According to the unmanned automatic guided vehicle, the lifting principle of the jacking mechanism in each jacking device of the hydraulic system 5 is the scissor fork jacking principle, the upper jacking groove plate 520, the lower jacking groove plate 521 and the two rotating plates 522 are connected through shafts to form a single scissor fork, the vertical lifting movement of the jacking mechanism can be realized, and the lifting is more stable. Moreover, because the horizontal movement displacement of the two jacking mechanisms is far smaller than the vertical movement position, the oil cylinder 511 with a smaller stroke can be used for completing the lifting amount of a larger stroke, and the oil cylinder 511 has a maximum stroke and a minimum stroke position which correspond to the highest position and the lowest position of the jacking mechanisms, so that the position of the fork stop is accurate and stable, and the high position and the low position are easier to be judged through photoelectric capture.

4. According to the unmanned automatic guided vehicle, the jacking mechanism of the jacking device in the hydraulic system 5 is provided with the return spring 525, the oil cylinder 511 is a single-acting cylinder, the risk of unsmooth falling and blocking exists when the oil cylinder 511 is jacked to the maximum position and falls back, the return spring 525 always provides thrust for the oil cylinder 511, the falling process is smoother, and no blocking risk exists.

5. The two jacking mechanisms in each fork leg 2 of the unmanned automatic guided vehicle are fixedly connected through a connecting rod 53, so that the two jacking mechanisms act synchronously, and meanwhile, the four jacking mechanisms are integrally connected and fixed through the covering forks. The jacking uses the principle of scissor fork jacking, and the action area of the jacked upper jacking trough plate 520 is large, so that the covering fork cannot deform due to load. The two oil flows are synchronized by the synchronizing valve 55, so that the piston speeds of the two oil cylinders 511 are the same, and the speed difference caused by different loads can be avoided. Therefore, the three points are multiple, so that the fork is vertically and horizontally moved upwards when the automatic guided vehicle takes the goods, the goods cannot shake, and the goods taking is more stable.

Example 2

The present embodiment provides an unmanned automated guided vehicle similar to that of embodiment 1, except that the control unit 71 has other functions. The control unit 71 is configured to determine whether the distance is smaller than a set threshold. When the distance is smaller than the set threshold, the control unit 71 drives the driving wheel mechanism 3 to stop, so that the AGV is protected from colliding with an obstacle during running, the automatic guided vehicle is protected from being damaged, and objects around the moving path of the automatic guided vehicle can be protected.

Example 3

The embodiment provides a cargo handling system, which comprises a plurality of mini unmanned AGV, wherein the mini unmanned AGV are matched with each other, and can handle a large amount of cargos in different places to the same point or a plurality of target places. The mini unmanned AGV is the unmanned automatic guided vehicle according to embodiment 1 or embodiment 2. The path planning method among the mini unmanned AGV adopts the existing path avoiding and running modes among the AGV.

Example 4

The present embodiment provides a guidance method for an unmanned automated guided vehicle according to embodiment 1 or 2. The guiding method comprises the following steps.

Step one, two first supporting points are formed through the two driving wheels 33, the two driven wheels 41 rotate around the rotating shaft 43 to form a second supporting point, and the two first supporting points and the second supporting point form a three-supporting-point structure of the automatic guided vehicle. The step realizes the supporting function through the structure formed by the three fulcrums, and can enable goods or materials to stably move subsequently.

And step two, driving the driving wheels 33 of the two driving wheel mechanisms 3 to rotate. The two first fulcrums enable the two fork legs 2 to move synchronously, and the second fulcrums enable the vehicle body 1 to move synchronously along with the two fork legs 2. The step is used for enabling the automatic guided vehicle to move stably and move along a preset path.

And step three, controlling the liquid inlet amount of the synchronous valve 55 through the pump station 54, and driving the two jacking devices to synchronously lift corresponding synchronous jacking ends by the synchronous valve 55 so as to jack the covering fork with the load positioned on the load surface. The step is used for realizing the lifting process of the goods or the materials, so that the goods or the materials are convenient to lift or put down.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. An automated guided vehicle for unmanned transport, comprising:

a vehicle body;

2. The automated guided vehicle of claim 1, wherein each jacking device comprises a cylinder, a second fixed seat, at least two jacking mechanisms, and at least one connecting rod; the second fixing seat is fixed in the fork leg; the oil cylinder is arranged on the second fixed seat, receives the hydraulic oil distributed by the synchronous valve and is used for driving one of the jacking mechanisms to do lifting action; the two ends of each connecting rod are respectively connected with the lifting ends of two adjacent jacking mechanisms, and the lifting ends of the jacking mechanisms are the synchronous jacking ends.

3. The automated guided vehicle of claim 2, wherein each jacking mechanism comprises two upper jacking channel plates, two lower jacking channel plates, four rotating plates, a front fixed plate, a rear fixed plate, a return spring, a jacking plate, a jacking connecting plate, two rotating shafts and two sliding shafts; the front fixing plate and the rear fixing plate are fixed on the fork legs and are separated to form a first mounting space; the two lower jacking groove plates are arranged in the first installation space and separated to form a second installation space; two ends of each lower jacking trough plate are respectively fixed on the front fixing plate and the rear fixing plate and provided with a first circular through hole and a first horizontal waist hole; one rotating shaft penetrates through the first two round through holes, and one sliding shaft penetrates through the first two horizontal waist holes; each upper jacking trough plate is positioned above one lower jacking trough plate and is provided with a circular through hole II and a horizontal waist hole II; the two upper jacking groove plates are connected through the jacking connecting plate; the other rotating shaft penetrates through the two circular through holes II, and the other sliding shaft penetrates through the two horizontal waist holes II; the middle parts of the two rotating plates are rotatably connected, and the end parts of the two rotating plates are respectively sleeved on the same ends of the two rotating shafts and the two sliding shafts to form a group of single-piece scissors fork; the middle parts of the other two rotating plates are rotatably connected, and the end parts of the other two rotating plates are respectively sleeved on the same other ends of the two rotating shafts and the two sliding shafts to form another group of single-piece scissors fork; one end of the reset spring is fixed on the front fixing plate, and the other end of the reset spring is fixed on the jacking plate; the jacking plate is fixed with the sliding shaft positioned on the lower side, and the oil cylinder is used for pushing and pulling the corresponding jacking plate of the jacking mechanism.

4. The automated guided vehicle of claim 1, further comprising:

5. The automated guided vehicle of claim 4, wherein the electronic control system further comprises a lithium battery; the lithium battery is installed on the vehicle body and used for supplying power to the control unit, the driving wheel mechanism, the hydraulic system and the navigator.

6. The automated guided vehicle of claim 5, wherein the electronic control system further comprises at least two crash sensors and a crash-proof touch edge; wherein at least one impact sensor is mounted on the front end of the fork leg, wherein at least another impact sensor is mounted on the rear of the vehicle body; the collision sensor is used for emitting laser and determining the distance between the collision sensor and an object in the laser irradiation direction according to the laser return time; the control unit is used for judging whether the distance is smaller than a set threshold value or not; when the distance is smaller than the set threshold value, the control unit drives the driving wheel mechanism to stop acting; the anti-collision contact edge is arranged on the rear part of the vehicle body and is of an elastic structure; wherein the lithium battery is further used for supplying power to the collision sensor.

7. The automated guided vehicle of claim 4, wherein the electronic control system further comprises a power switch, a crash stop switch, and two actuators; the power switch is used for turning on or off the lithium battery; the emergency stop switch is an emergency stop structure of the automatic guided vehicle; the two drivers are respectively used for controlling servo motors of the two driving wheel mechanisms.

8. The automated guided vehicle of claim 1, wherein the bevel gear set comprises a driving spiral bevel gear and a driven spiral bevel gear that mesh with each other; the servo motor is used for driving the driving spiral bevel gear to rotate; the driven spiral bevel gear is sleeved on the driving shaft.

9. The automated guided vehicle of claim 8, wherein each drive wheel mechanism further comprises a speed reducer; the output shaft of the servo motor is connected with the input end of the speed reducer, and the driving spiral bevel gear is sleeved on the output end of the speed reducer.

10. A method of guiding an automated guided vehicle according to any of claims 1-9, comprising the steps of: