CN111807266B

CN111807266B - Safety height limiting system suitable for cargo-carrying AGV and operation method thereof

Info

Publication number: CN111807266B
Application number: CN202010643360.9A
Authority: CN
Inventors: 樊雨; 朱宝昌; 周敏龙; 刘杰
Original assignee: Shanghai Noblelift Intelligent Technology Co ltd; Noblelift Intelligent Equipment Co Ltd
Current assignee: Shanghai Noblelift Intelligent Technology Co ltd; Noblelift Intelligent Equipment Co Ltd
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2021-12-31
Anticipated expiration: 2040-07-07
Also published as: CN111807266A

Abstract

The invention relates to the field of automation logistics, in particular to mechanical design and system design of an AGV. The invention is realized by the following technical scheme: the utility model provides a safe high restraint system suitable for carry cargo formula AGV, contains car control system, automobile body, carrier and the relative automobile body elevating gear that the drive carrier goes up and down, still contains the height sensor who is used for acquireing the current height value H of carrier and is used for acquireing the load sensor of the current thing weight T that carries of carrier. The invention aims to provide a safety height limiting system suitable for a loading type AGV and an operation method thereof, which can effectively identify the loading height of a vehicle, evaluate the loading safety degree of the current height and effectively improve the safety of the running state of the AGV.

Description

Safety height limiting system suitable for cargo-carrying AGV and operation method thereof

Technical Field

The invention relates to the field of automation logistics, in particular to mechanical design and system design of an AGV.

Background

An AGV (Automated Guided Vehicle) is a Vehicle equipped with an electromagnetic or optical automatic guide device, and is capable of traveling along a predetermined guide path. With the progress of information technology and the maturity of automation level, the application of the AGV is more and more common, and the AGV is widely applied to various fields of transportation, stacking and logistics.

For example, CN201920154817.2 discloses an AGV cart, which includes an automatic guidance and power system for controlling the forward movement of the cart body. AGV carts are often provided with load carrying members such as forks which are raised and lowered by power members such as rams.

During the operation of industrial vehicles, it is necessary to ensure the safety of the work and to limit the actual cargo weight of the vehicle. If the actual cargo weight of the vehicle is greater than its safe threshold, the vehicle is susceptible to damage or rollover conditions. And the weight safety thresholds of the forks are different at different height positions. In particular, when the forks are in a higher position, the weight safety threshold is lower.

When the AGV lifts goods and transports the goods, the goods are too heavy at a certain height in the market, and the goods exceed the safety threshold value, so that the AGV is unstable in running or heels.

Disclosure of Invention

The invention aims to provide a safety height limiting system suitable for a loading type AGV and an operation method thereof, which can effectively identify the loading height of a vehicle, evaluate the loading safety degree of the current height and effectively improve the safety of the running state of the AGV.

The technical purpose of the invention is realized by the following technical scheme: the utility model provides a safe high restraint system suitable for carry cargo formula AGV, contains car control system, automobile body, carrier and the relative automobile body elevating gear that the drive carrier goes up and down, still contains the height sensor who is used for acquireing the current height value H of carrier and is used for acquireing the load sensor that the carrier carries thing weight T currently, and car control system contains:

the communication module is in communication connection with the height sensor and the load sensor;

the storage module is used for storing a mapping table which reflects the mapping relation between the height value and the corresponding maximum carrying weight Tmax;

the judging module is used for judging the size relation between the Tmax corresponding to the current height value H and the current carrying weight T;

and the control module adjusts the vehicle running state according to the judgment result of the judgment module.

Preferably, the vehicle control system is a single chip microcomputer installed on the vehicle body.

Preferably, the height sensor is a pull switch, the pull switch includes a fixed portion and a pull wire, the fixed portion is mounted on the vehicle body, the pull wire is mounted on the fixed portion, and the other end of the pull wire is connected to the luggage carrier.

Preferably, the lifting device comprises an oil tank and a lifting oil cylinder connected with the oil tank, the lifting oil cylinder drives the carrier to lift, and the oil tank is mounted on the vehicle body.

Preferably, the height sensor is a level sensor installed in the oil tank and measuring a level of oil in the oil tank.

Preferably, the number of the height sensors is two, the height sensors are respectively a first height sensor and a second height sensor, H1 and H2 are respectively measured, and when the vehicle control system identifies that H1 and H2 at the current moment are different, the control module closes the vehicle to run.

Preferably, the load sensor is a current detector for detecting an operating current value I of the AGV, and the storage module further stores a current mapping table for reflecting the load T and the operating current value I.

Preferably, the load sensor is a pressure sensor.

Preferably, the pressure sensor is a hydraulic sensor, and the hydraulic sensor is used for measuring the oil pressure in an oil tank or a lifting oil cylinder.

Preferably, the oil tank and the lifting oil cylinder are connected by an oil pipe, and the hydraulic sensor is arranged in the oil pipe.

Preferably, the number of the load sensors is two, the load sensors are respectively a first load sensor and a second load sensor, T1 and T2 are respectively measured, and when the vehicle control system identifies that T1 and T2 at the current moment are different, the control module closes the vehicle to run.

A method of operating a safety height limiting system for a loaded AGV, comprising the steps of:

s01, editing a mapping table;

a mapping table reflecting the height value H of the carrier and the corresponding maximum carrier weight Tmax at the position is edited in a user-defined mode and is stored in a storage module in the vehicle control system;

s02, weight identification;

a load sensor arranged on an AGV acquires the current load weight T;

s03, height identification;

a height sensor arranged on the AGV acquires a height value H of the carrier;

s04, a safety threshold value obtaining step;

the vehicle control system searches in a mapping table to find out the maximum carrying weight Tmax corresponding to the carrying frame height value H;

s05, comparing and processing;

and the vehicle control system compares the current load weight T with the maximum load weight Tmax, judges whether the current load weight T exceeds a weight safety threshold value, and switches the working state of the AGV according to the judgment result.

Preferably, the method further includes, in step S03, a height recognition self-test step of:

the AGV is provided with two height sensors, namely a first height sensor and a second height sensor, which are used for respectively measuring height values H1 and H2 of the carrier, the vehicle control system compares the values of H1 and H2, and when the two values are inconsistent, the AGV is controlled to stop running.

Preferably, in S02, the method further includes a weight identification self-check step:

the AGV is provided with two load sensors, namely a first load sensor and a second load sensor, which are used for respectively measuring the load weight values T1 and T2 of the load carrier, the vehicle control system compares the values of T1 and T2, and when the two values are inconsistent, the AGV is controlled to stop running.

In conclusion, the invention has the following beneficial effects:

1. and automatically identifying the lifting height of the goods, and comparing the weight of the goods with the loading threshold corresponding to the height position.

2. When the weight of the goods is larger than the loading threshold value of the height, the operation of the AGV can be stopped or the height of the carrier is reduced, the AGV is prevented from tilting, and the safety of the AGV is improved.

3. And the height sensor and the load sensor are subjected to a data comparison process, if the data are inconsistent, the system is judged to be abnormal, and warning notification is carried out on the working personnel.

Description of the drawings:

FIG. 1 is a schematic diagram of a first embodiment;

FIG. 2 is a logic diagram of a vehicle control system according to a first embodiment;

FIG. 3 is an enlarged schematic view at A in FIG. 1;

fig. 4 is an enlarged schematic view at B in fig. 1.

In the figure:

1. the lifting device comprises a lifting device 11, an oil tank 12, a lifting oil cylinder 7, a load sensor 71, a first load sensor 72, a second load sensor 8, a height sensor 81, a first height sensor, a pull switch 811, a fixing part 812, a pull wire 82, a second height sensor 91, a vehicle body 92 and a carrier rack.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Embodiment 1, as shown in fig. 1, a safety height limiting system for a loaded AGV and a method of operating the same includes a vehicle body 91. The carrier 92 may be a fork for direct handling of the cargo. The lifting device 1 is mounted on the vehicle body 91, and the AGV directly drives the carrier 92 to lift by the operation of the lifting device 1.

Specifically, in the present embodiment, the lifting device 1 includes an oil tank 11 and a lifting cylinder 12. The carrier 92 may be directly connected to the gantry and the lift cylinder 12 may be connected to the gantry to propel the gantry to move up and down.

The guiding device, positioning device and traveling device of the AGV can be directly used by referring to the components in the prior art, and specific structural or functional changes are not needed in the scheme.

As shown in fig. 2, the AGV controls the operation of the vehicle by a control command from the vehicle control system. The vehicle control system may be a single chip microcomputer mounted on the vehicle body 91. The vehicle control system comprises a control module, a storage module, a judgment module and a communication module. The communication module can be a communication module in the prior art, and is used for being in communication connection with each sensor on the AGV, so that the vehicle control system can receive data of each sensor. The storage module is an electronic storage device in the prior art, such as a ROM, and the storage module stores a mapping table edited by an engineer, where the mapping table reflects the maximum safe carrying weight of the AGV carrier 92 at different heights, i.e. the value of Tmax.

The control module is used for controlling the running state of the AGV vehicle, such as the switching between the stop state and the running state. The control module and the judgment module can be written by using a programming language, and the specific programming language and codes are not limited by the present invention, and are the contents of the prior art, and can be implemented by persons skilled in the art, and the details are not described herein.

In the specific operation method, S01, as mentioned above, the engineer completes the editing of the mapping table reflecting the mapping relationship between the height value H of the carrier 92 and the corresponding maximum carrier weight Tmax, and stores the mapping table in the storage module.

And S02, a weight identification step.

As shown in fig. 1, a load sensor 7 is mounted on a body 91 of the AGV, and the load sensor 7 is used to read the weight T of the current load. Further, in the present embodiment, the load sensors 7 are two in number. The first load sensor 71 is embodied as a current detector mounted on the vehicle body 91 for detecting the passing current I. In the actual operation of the AGV, when the carrier rack 92 is driven by the lifting device 1 to carry a load, the load weight T of the load is positively correlated to the operating current I, and a mapping table storing T and I is also implemented in the system, that is, the vehicle control system can obtain the corresponding load weight according to the current operating current I, which is denoted as T1.

On the other hand, the second load sensor 72 is implemented as a hydraulic sensor, and the hydraulic sensor can be a mature product in the prior art and is used for sensing the pressure value of the oil pressure in the lifting device. In the present case, the oil tank 11 is connected to the lifting cylinder 12 through an oil pipe, the hydraulic sensor is installed in the oil pipe, and the vehicle control system also obtains the corresponding cargo weight, which is denoted as T2, through the current hydraulic value of the second load sensor 72.

At this time, the vehicle control system compares the values of T1 and T2, and if T1 and T2 are the same or similar, the result is normal. If T1 and T2 are not consistent or the difference exceeds the preset normal error range, it can be determined that a problem occurs in one of the load sensors 7 at present, and the vehicle control system starts to perform adjustment operation on the driving condition of the AGV, such as stopping the AGV, stopping the AGV from running, sounding an error sound, and the like.

For example, oil in the oil tank 11 deteriorates, affecting the oil pressure; for another example, the electromagnetic interference in the working environment is severe, which affects the accuracy of current detection, and may cause the data of T1 and T2 to be inconsistent.

If the T1 and the T2 do not have the inconsistency, the system continues to operate.

And S03, height identification.

In this step, the height sensor 8 mounted on the AGV acquires the current height value H of the carrier rack 92. Also, in the present embodiment, the height sensors 8 are two in number. As shown in fig. 1 and 3, the first height sensor 81 is implemented in the form of a pull switch. The pull switch is also a product directly available in the prior art, and includes a fixing portion 811 mounted on the vehicle body 91. The pull wire 812 has one end mounted to the fixing portion 811 and the other end mounted to the carrier frame 92. When the carrier 92 is raised, the pull wire 812 is pulled out. The pull switch obtains the height of the carrier rack 92 when the pull 812 is pulled out, which is denoted as H1.

As shown in fig. 1 and 4, another level sensor, namely, a second level sensor 82, embodied as a level sensor, is also commercially available in the prior art, and is mounted in the tank 11 for obtaining the current level position of the oil in the tank. When the oil in the oil tank 11 hits the lifting cylinder 12, the piston rod is lifted, and the carrier frame 92 is lifted. That is, there is a mapping relationship between the position of the oil in the oil tank and the lifting height of the carrier 92, and the vehicle control system can obtain the current lifting height of the carrier 92, which is denoted as H2, according to the liquid level data in the liquid level sensor.

Similarly, the vehicle control system compares the values of H1 and H2, and if H1 and H2 are the same or similar, it is normal. If H1 and H2 are inconsistent or the difference exceeds the preset normal error range, it can be determined that a problem occurs in one of the height sensors 8 at present, and the vehicle control system starts to adjust the driving condition of the AGV, for example, the AGV stops, does not run any more, and sounds an error tone.

For example, the oil tank 11 leaks oil. As another example, the carrier 92 may be jammed during descent and may not be lowered properly. This inconsistency in the data of H1 and H2 is caused.

If the inconsistency between H1 and H2 does not occur, the system continues to operate.

And S04, a safety threshold value acquisition step.

The height value H of the carrier rack 92 is obtained from S03, and at this time, the vehicle control system searches in the mapping table to find the maximum carrying weight Tmax corresponding to H.

And S05, comparing and processing.

In S02, the vehicle control system has obtained the current payload weight T. At this time, the vehicle control system compares the current load weight T with the maximum load weight Tmax obtained in S04, and determines the data size relationship between the two. If T is less than or equal to Tmax, the state is judged to be a safe state, and if T is greater than Tmax, the state is judged to be an overload state and a non-safe state. The engineer may pre-program specific actions after determining overload, such as stopping the operation, or controlling the carrier rack 92 to lower to the zero position immediately.

Embodiment 2 differs from embodiment 1 in that the number of load sensors 7 and height sensors 8 is only one in this embodiment. The load sensor 7 is a liquid level sensor provided inside the oil tank 11, and the height sensor 8 is a pull switch.

Since the number of the load sensors 7 and the height sensors 8 is only one, i.e., the comparison process of T1 and T2 is omitted, and the comparison process of H1 and H2 is omitted, the other means is the same as in embodiment 1.

The reason for adopting the pull switch as the height sensor is that the pull switch is a mechanical measurement switch, the working environment of the AGV usually adopts the technologies of magnetic strip guidance, laser positioning and the like, and the mechanical measurement switch is not easily subjected to electromagnetic interference, is not easily subjected to optical interference of on-site reflective glass, and has stable and reliable performance.

The reason for using a level sensor, which is mounted inside the tank 11 and is less susceptible to external disturbances, is also in view of data stability.

Claims

1. A safety height limiting system for a cargo AGV comprising a vehicle control system, a vehicle body (91), a carrier (92) and a lifting device (1) for driving the carrier (92) to lift relative to the vehicle body (91), characterized by further comprising a height sensor (8) for obtaining a current height value H of the carrier (92) and a load sensor (7) for obtaining a current load weight T of the carrier (92), the vehicle control system comprising: the communication module is in communication connection with the height sensor (8) and the load sensor (7); the storage module is used for storing a mapping table which reflects the mapping relation between the height value and the corresponding maximum carrying weight Tmax; the judging module is used for judging the size relationship between the Tmax corresponding to the current height value H and the current carrying weight T; the control module adjusts the vehicle running state according to the judgment result of the judgment module; when the maximum loading weight Tmax is smaller than the current loading weight T, the control module stops the AGV from running or reduces the height value of the loading rack (92); the vehicle-mounted intelligent control system is characterized in that the height sensors (8) are two, namely a first height sensor (81) and a second height sensor (82), H1 and H2 are respectively measured, when the vehicle control system identifies that H1 and H2 at the current moment are different, then the control module closes the vehicle operation, the load sensors (7) are two, namely a first load sensor (71) and a second load sensor (72), respectively measure T1 and T2, when the vehicle control system identifies that T1 and T2 at the current moment are different, then the control module closes the vehicle operation, the first load sensor (71) is a current detector, the second load sensor (72) is a hydraulic sensor installed in an oil pipe, the first height sensor (81) is a pull switch, and the second height sensor (82) is a liquid level sensor installed in the oil tank.

2. A safety height limiting system for a loaded AGV according to claim 1, wherein: the vehicle control system is a single chip microcomputer arranged on the vehicle body (91).

3. A safety height limiting system for a loaded AGV according to claim 1, wherein: the pull switch comprises a fixed part (811) and a pull wire (812), the fixed part (811) is installed on the vehicle body (91), the pull wire (812) is installed on the fixed part (811), and the other end of the pull wire is connected with the object carrier (92).

4. A safety height limiting system for a loaded AGV according to claim 1, wherein: the lifting device (1) comprises an oil tank (11) and a lifting oil cylinder (12) connected with the oil tank (11), the lifting oil cylinder (12) drives the object carrier (92) to lift, and the oil tank (11) is installed on the vehicle body (91).

5. A method of operating a safety height limiting system for a loaded AGV according to claim 1, including the steps of: s01, editing a mapping table; a mapping table reflecting the height value H of the carrier (92) and the corresponding maximum carrier weight Tmax at the position is edited in a user-defined way and is stored in a storage module in the vehicle control system; s02, weight identification; a load sensor (7) arranged on the AGV acquires the current load weight T; s03, height identification; a height sensor (8) arranged on the AGV acquires a height value H of the carrier rack (92); s04, a safety threshold value obtaining step; the vehicle control system searches in a mapping table to find out the maximum carrying weight Tmax corresponding to the height value H of the carrier (92); s05, comparing and processing; and the vehicle control system compares the current load weight T with the maximum load weight Tmax, judges whether the current load weight T exceeds a weight safety threshold value, and switches the working state of the AGV according to the judgment result.

6. A method of operating a safety height limiting system for a loaded AGV according to claim 5, wherein: in S03, the method further includes the step of height recognition self-test: two height sensors (8) are arranged on the AGV, namely a height sensor I (81) and a height sensor II (82), the height values H1 and H2 of the object carrier (92) are respectively measured, the vehicle control system compares the values of H1 and H2, and when the two values are inconsistent, the AGV is controlled to stop running.

7. A method of operating a safety height limiting system for a loaded AGV according to claim 5, wherein: in S02, the method further includes a weight identification self-check step: the AGV is provided with two load sensors (7) which are a first load sensor (71) and a second load sensor (72) respectively, the load weight values T1 and T2 of the object carrier (92) are measured respectively, the vehicle control system compares the numerical values of T1 and T2, and when the two numerical values are inconsistent, the AGV is controlled to stop running.