Method of Controlling Transport Vehicles for Transporting Sliver Cans in a Spinning Mill and a Transport Vehicle for Performing the Method

Abstract

The invention relates to method of controlling a transport vehicle for transporting exactly one sliver can (2) in a spinning mill between a filling station (3) for depositing a sliver into cans (2) and working positions of the cans (2) at workstations of the spinning machines (4), which ensures supplying the spinning machines with full cans (2) with a sliver. A request for can (2) replacement at the respective workstation of the spinning machine (4) is generated on the basis of the information from the spinning machines (4) about the remaining quantity of the sliver in the cans (2) at the individual workstations of the spinning machines (4), or information about the removal of the can (2) by the operator during spinning, the information being passed to the control system (5) of the spinning mill, which on the basis of this request predicts the moment of the conveying of the can (2) by the transport vehicle (1) to the respective workstation and the request is placed into a request queue which is optimized for the maximum utilization of the spinning machines (4) with respect to the current position and working activity of the transport vehicles (1), whereby in order to control the individual transport vehicles (1), data/information from the localization system, as well as data/information from the transport vehicle (1), is evaluated and processed.

The invention also relates to a transport vehicle for performing the above described method.

Claims

1. A method of controlling a transport vehicle for transporting exactly one sliver can (2) in a spinning mill between a filling station (3) for filling cans (2) with a sliver and can (2) working positions near workstations of spinning machines (4), which ensures that the spinning machines are supplied with full sliver cans (2), characterized in that a request to replace the can (2) at the respective workstation of the spinning machine (4) is made on the basis of information from the spinning machines (4) about the remaining amount of the sliver in the cans (2) near the individual workstations of the spinning machines (4), or on the basis of information about the removal of the can (2) by the operator during spinning, the information being passed to the control system (5) of the spinning mill, which on the basis of this request predicts the moment of the conveying of the can (2) by the transport vehicle (1) to the respective workstation, whereby the request is placed into a request queue which is optimized for the maximum utilization of the spinning machines (4 with respect to the amount of the sliver in the individual cans, the current position and utilization and the loading of the transport vehicles (1).

2-13. (canceled)

Description

DESCRIPTION OF THE DRAWINGS

[0027] The invention will be described in more detail in the enclosed drawings, where:

[0028] FIG. 1 shows a scheme of the system of a spinning mill,

[0029] FIG. 2a shows a diagram of the vehicle and the virtual areas around it, and

[0030] FIG. 2b shows a view of the transport vehicle with an indicated can being transported.

EXAMPLES OF EMBODIMENT OF THE INVENTION

[0031] The method of controlling transport vehicles 1 for transporting sliver cans 2 in a spinning mill between a filling station 3 for filling sliver into cans 2 and working positions of cans 2 at workstations of spinning machines 4 will be described with reference to an exemplary embodiment of a spinning mill comprising at least one filling station 3, in which a sliver is deposited in sliver cans 2 in a known manner. The filling station 3 is connected to one or more preparatory machines, for example carding, combing or drawing machines, and a storage device of empty cans 2 and a storage device of full cans 2. Each can 2 in the spinning mill is assigned a unique identifier. When filling the can 2 with a sliver, the quantity of the sliver deposited into the can 2 is monitored and, after completion of filling, each filled can 2 on the basis of its identifier is assigned individual information about the length/quantity of the sliver deposited in the can 2 and this information for the respective can is stored in the memory of the control system 5 of the spinning mill.

[0032] Each transport vehicle 1 is designed to transport exactly one can 2, either full or empty, the can being provided with its own rolling members for movement on the floor of the spinning mill, so that, when being handled, it is pulled or pushed by the transport vehicle and is situated outside the ground plan of a moving means of the transport vehicle 1. The transport vehicle 1 is provided with a catching member for catching and holding the can and, if necessary, also with stops and support members for the transported can 2, as shown in FIG. 2b.

[0033] In the spinning mill, a localization system is provided which contains information about the infrastructure of the spinning mill, i.e. the position of the filling station 3 and its two storage devices of cans 2 and the position of the spinning machines 4. The localization system of the spinning mill further comprises a plurality of stationary navigation points/anchors 6 of known position relative to the spinning mill infrastructure, the stationary navigation points/anchors 6 and the control system 5 of the spinning mill being interconnected. The navigation points/anchors and the control system 5 of the spinning mill are wirelessly or cable interconnected to transmit data or to set the power and radio channel of the individual navigation points/anchors 6. In a particular embodiment, the connection is made in the Ultra Wideband standard.

[0034] Each spinning machine 4 is provided with a known control system (not shown) connected to the control system 5 of the spinning mill, which usually comprises a control unit for each workstation which is provided with a memory for storing information about the quantity of the sliver deposited in a new can 2 after it has replaced the preceding can and has been placed to a working position at a respective workstation of the spinning machine. The control unit of the workstation of the spinning machine is further provided with means for monitoring the quantity of the processed sliver from the can 2, i.e., for example, the quantity of the spun yarn, and/or for monitoring the distance travelled by the sliver feeding roller or sliver draw-off roller and for generating the information about the quantity of the sliver remaining in the can 2. The information about the quantity of the sliver remaining in the can 2 is passed to the control system 5 of the spinning mill. According to a particular arrangement of the spinning machine, the control unit of the respective workstation, it is the control unit of a machine section or the central control system of the spinning machine that can be used for monitoring the quantity of the sliver remaining in the can 2.

[0035] The information about the remaining quantity of the sliver in the can 2 is evaluated in the control system of the spinning machine 4 usually for each natural yarn break by comparing the quantity/weight of the sliver originally deposited in the can 2 to the quantity/weight of the spun yarn and if the difference between these values is within a predetermined interval, a request for can 2 replacement is generated and transmitted to the control system 5 of the spinning mill, which on the basis of this request predicts the moment of the conveying of the can 2 by the transport vehicle 1 to the respective workstation, whereby this request is stored in the request queue which is optimized for the maximum utilization of the spinning machines 4 with regard to the quantity of the sliver in the individual cans 2, current position and utilization of the transport vehicle 1.

[0036] If the can 2 is completely or almost completely empty or if the can 2 has been removed by the operator, a priority can 2 replacement request is made in the control system of the spinning machine, which, in the control system 5 of the spinning mill, is placed into the queue of requests for can 2 replacement to a priority position.

[0037] The basic part of the transport vehicle 1 is a moving means in which two individually driven drive wheels are arranged, of which the left wheel is coupled to the left motor and the right wheel to the right motor, and both motors are independently connected to the control unit 11 of the transport vehicle 1 and are equipped with rotation sensors 17 which allow the control unit 11 to monitor the speed and number of revolutions and with means for wireless communication with the control system 5 of the spinning mill. The transport vehicle 1 further comprises a transponder 12 for communication with the control system of the spinning mill, with the localization system of the spinning mill and with the control unit 11 of the transport vehicle 1. The transponder 12 is either part of or coupled to the control unit 11 of the transport vehicle 1. On the basis of the radio (wireless) communication between the navigation points/anchors 6 and the transponder 12, the position of the transport vehicle 1 is evaluated by the control system 5 of the spinning mill, based on triangulation. The control unit 11 of the transport vehicle 1 also comprises an inertial sensor 14 consisting of a gyroscope, an accelerometer and a magnetometer, and further comprises a battery management system 15 for monitoring the voltage of the battery cells of the transport vehicle and distance sensors 16 (LIDAR) which serve to monitor the approach to an obstacle, by means of which the control unit 11 creates a virtual approach area Z1 and a virtual near surroundings area Z2 around the vehicle 1. If there is no obstacle in the virtual approach area Z1, the vehicle 1 moves at full speed, which is approximately 2 m/s. If an obstacle appears in the virtual approach area Z1, the speed of the vehicle 1 is reduced, the magnitude of the reduction depending on whether the obstacle is passed in the direction of movement or whether it is in the direction of movement in front of the transport vehicle 1. When passing an obstacle, the speed reduction is smaller. If there is an obstacle in the virtual near surroundings area Z2, the transport vehicle 1 immediately stops. The motor of each of the drive wheels of the transport vehicle 1 is coupled to a current flow meter which is part of or coupled to the control unit 11, and in the event of an unexpected decrease in the magnitude of the current, particularly during acceleration or smooth driving, this fact is evaluated as a slip of the respective wheel, and information about this event is transmitted to the control system 5 of the spinning mill, where it is used to specify the current position of the transport vehicle.

[0038] By means of wireless communication of its control unit 11 with the control system 5 of the spinning mill, the transport vehicle 1 shares data on the battery condition, in particular the minimum value of the cell voltage, the current values of the wheel counters and data from the inertial sensor 14 formed by the coordinates X-Y-Z of the gyroscope, X-Y-Z of accelerometers, and X-Y-Z of the magnetometer. For efficient data communication, the data from the sensors is transmitted continuously and battery data on request. Data on approaching to an obstacle and data on critical battery voltage is transmitted immediately at the respective event. Due to the voltage drop of the battery cells, the control unit 11 of the transport vehicle 1 generates a request to the control system 5 of the spinning mill to drive to the charging station.

[0039] The control system 5 of the spinning mill can be integrated into the control system of one of the spinning machines 4 and the stationary navigation points/anchors 6 can be located on the frames of the spinning machines 4, whereby a sufficient distance of the navigation points/anchors 6 from the metal parts of the machines must be maintained so as not to affect the parameters of the anchors' antennas 6, which is achieved, for example, by using plastic holders.

[0040] Based on the commands from the control system 5 of the spinning mill, the control unit 11 of the transport vehicle 1 controls the rotation of the left-wheel drive motor and the rotation of the right-wheel drive motor by commands to change the orientation by a certain angle and/or commands to travel over a specified distance, thereby guiding the transport vehicle 1 along an optimal path, which has been chosen by the control system 5 of the spinning mill. Reaching the desired position is evaluated by the control system 5 of the spinning mill similarly to the PTP (point-to-point) positioning of industrial robotics. A zone is designated for each point of the intended path and, if the transport vehicle reaches that zone, its position is evaluated as fulfilled. The zones are either circular, for example, when the transport vehicle 1 bypasses an obstacle or arrives at the desired end position, or rectangular, for example, when the transport vehicle 1 passes through an aisle between the machines, where an error in the longitudinal direction is not as critical as in the transverse direction.

[0041] Based on the information about the quantity of the sliver remaining in the can 2 by the individual workstations of the spinning machines or on the information about the removal of the can 2 by the operator at a specific workstation of the spinning machine, the spinning machine 4 generates a request for a can 2 exchange at the respective workstation and passes this request to the control system 5 of the spinning mill. On the basis of this request, the spinning system 5 of the spinning mill predicts the moment of conveying the can 2 by the transport vehicle 1 to the respective workstation of the spinning machine 4 and the request with the information about the moment of conveying the can 2 is stored in the memory of the control system 5 of the spinning mill in the queue of requests. The request queue for the replacement of the can 2 is optimized for the maximum utilization of the spinning machines 4 with regard to the current position and working activity of the transport vehicle 2, whereby in order to control the individual transport vehicles (1), data/information from the localization system of the spinning mill as well as data/information from the transport vehicle (1) is evaluated and processed.

[0042] The position, direction and speed of the transport vehicle 1 relative to the spinning infrastructure are monitored by mutual communication between the transport vehicle 1 and the stationary anchors 6, the information about them is transmitted to the control system 5 of the spinning mill and on the basis of this information commands are created in the control system 5 of the spinning mill for the transport and other activities of the transport vehicle 1.

INDUSTRIAL APPLICABILITY

[0043] The invention can be used to automate the replacement of cans in spinning mills.

LIST OF REFERENCES

[0044] 1 transport vehicle of cans

[0045] 11 control unit of transport vehicle

[0046] 12 transponder of transport vehicle

[0047] 14 inertial sensor

[0048] 15 battery management system

[0049] 16 sensor(s) of distance (LIDAR)

[0050] 17 sensor of motor rotation

[0051] Z1 virtual approach area

[0052] Z2 virtual near surroundings area

[0053] 2 can

[0054] 3 filling station of sliver into cans

[0055] 4 spinning machine

[0056] 5 control system of spinning mill

[0057] 6 anchor