CROSS REFERENCE TO RELATED APPLICATION

The present application claims the priority benefits of International Patent Application No. PCT/EP2017/076332, filed Oct. 16, 2017, and claims benefit of German patent application DE 10 2016 119 839.0, filed on Oct. 18, 2016.

BACKGROUND AND FIELD OF THE INVENTION

The invention relates to a method for the positioning of a gantry lift stacker, designed as a straddle carrier, for containers in order to position a container to be set down at a preselected distance behind an already set-down container in such a way that, in relation to its longitudinal orientation, the container to be set down is flush with the longitudinal direction of the set-down container, wherein the gantry lift stacker is moved by means of travel supports, travel drives and a controller cooperating therewith, and measurement signals from sensors disposed on the gantry lift stacker are processed by the controller for the purpose of moving and positioning the gantry lift stacker and the container to be set down.

The invention also relates to a gantry lift stacker for containers, in particular for carrying out a method for the positioning of a gantry lift stacker, having travel supports, travel drives and a controller cooperating therewith, having a load picking-up means for containers which can be raised and lowered, having at least one sensor for the positioning of the gantry lift stacker and of the container to be set down.

German patent DE 10 2008 011 539 B3 discloses a fully automatic gantry lift stacker with local radio location and laser steering. For the purposes of vehicle location and navigation the gantry lift stacker is fitted with a plurality of different sensor systems, the signals of which are evaluated, monitored and transmitted to a system of electronic controllers. The vehicle location is carried out using local radio location systems which operate with stationary radio transponders located on the operating surface. Laser scanners are mounted on the vehicle for the purpose of automatic steering of the gantry lift stacker upon reaching a container stack.

U.S. Pat. No. 5,780,826 discloses a container handling apparatus which is designed to be self-driving. The container handling apparatus is fitted with means which permit it to detect a position of the container in the container storage area and to read an identification code attached to the container. The container handling apparatus also includes a first means for detecting the two-dimensional horizontal position of the container, a second means for detecting an additional two-dimensional horizontal position of the container and a means for detecting the vertical position of the container.

The utility model DE 20 007 016 156 U1 discloses a gantry lift stacker having automatic steering for transportation and stacking of containers. The gantry lift stacker consists in a conventional manner of a gantry frame which is U-shaped as seen in the travel direction of the gantry lift stacker and has vertical gantry struts. Two travel supports each with a plurality of electrohydraulically steerable wheels are disposed at a lower end of the gantry struts. In order to set down a container on at least one other container or to pick up a container from at least one further container, the gantry lift stacker travels over a container which can stand alone or in a row of containers. At this juncture, the travel supports move left and right along one or a plurality of containers. Automatic steering is used to assist the driver in steering. For this purpose, a laser scanner is disposed at the front on one of the travel supports and therefore laterally offset with respect to the respective container, the measurement signals of this laser scanner being used to determine a distance between the travel support and a side wall of the container. This is effected in that the laser scanner transmits laser beams in horizontal directions in an angular range between the longitudinal axis of the travel support and the side wall of the container of about 55 degrees and these are reflected from an obstacle, e.g. in the form of the side wall, forwards and laterally of the travel support. The distance to the obstacle is then calculated from a difference in transit time between the transmitted and reflected beam. At this juncture, only obstacles in said angular range of 55 degrees are detected, i.e. only in relation to obstacles or side walls upstream of the travel supports. The distances thus measured to the side wall of the upstream container and the associated measurement angles are then transmitted to an electronic controller which calculates therefrom the distance between the travel support and the side wall of the container. These distances are also used, if necessary, for automatic steering purposes, and, on the basis thereof, desired steering angles are calculated for the turning of the wheels and are transmitted to the steering computer which controls the turning of the wheels. The automatic steering of the gantry lift stacker is also orientated according to the position of the upstream side walls of the container.

It is generally known to use so-called twin spreaders for handling containers. By means of a twin spreader, a gantry lift stacker can simultaneously pick up and transport two containers one behind the other. For the purpose of picking up two container one behind the other in a predetermined frame the twin spreader can compensate for imprecise positioning of the two set-down containers.

In terms of the invention, containers are understood to be ISO containers. ISO containers weigh up to about 38 t and are generally understood to be standardised bulk containers with standardised pick-up points or corners for load picking-up means. ISO containers are conventionally 20, 40 or 45 feet long. ISO containers with a length of 53 feet also already exist. In the area of ISO containers, in addition to the closed containers, refrigerated containers—so-called reefers—and a multiplicity of other container types are also known.

SUMMARY OF THE INVENTION

The present invention provides a method for the positioning of a gantry lift stacker and a gantry lift stacker in order to increase the transport throughput of a gantry lift stacker, e.g. for more rapid handling of containers or more rapid loading and unloading of containers ships.

In accordance with the invention, in the case of a method for the positioning of a gantry lift stacker, designed as a straddle carrier, for containers in order to position a container to be set down behind an already set-down container in such a way that, in relation to its longitudinal orientation, the container to be set down is flush with the longitudinal direction of the set-down container, wherein the gantry lift stacker is moved by means of travel supports, travel drives and a controller cooperating therewith, and measurement signals from sensors disposed on the gantry lift stacker are processed by the controller for the purpose of moving and positioning the gantry lift stacker and the container to be set down, positioning one behind the other, which permits simultaneous picking up of two containers, is achieved in that by means of at least one sensor a position of a rear wall of an already set-down container is determined and then the container to be set down is set down from the gantry lift stacker at a preselected distance behind the set-down container in such a way that, in relation to its longitudinal orientation, the container to be set down is flush with the longitudinal direction of the set-down container.

By the determination of the position of a rear wall of an already set-down container, it is ensured that the container to be set down can be positioned with a high level of precision behind the set-down container. This positioning can be carried out both by manual and also automatic or semi-automatic operation. One advantage of the invention is thus that a row of containers with slight irregularity can thereby be formed, and storage space can be saved by uniform and narrow spacing of the containers.

Within the scope of the invention, determination of the position of the rear wall of an already set-down container is understood to be a measurement which serves to detect the upper edge or side edges of the already set-down container. In particular, the position of the rear wall is understood to be a measurement of the distance to the container upper edge.

Furthermore, provision is made in accordance with the invention that, in automatic operation, the container to be set down is set down automatically by means of an automatically acting controller.

Automatic operation, in which the controller positions the gantry lift stacker and the container to be set down without active intervention of a driver is advantageous for relieving pressure on the driver, in particular during complex maneuvering which requires high levels of concentration.

A further advantage of the invention is that the automatically acting controller is activated and deactivated by a driver.

In this way, even in an automatic operation, the driver retains control since he can manually activate and deactivate the automatic operation.

A further advantageous embodiment involves the container to be set down being set down in manual operation in which the gantry lift stacker is operated manually by a driver with the assistance of the measurement values supplied by the sensors.

Such an operation assists the driver in controlling the gantry lift stacker and therefore relieves him of pressure but at the same time he continues to have manual control over the gantry lift stacker. Therefore, in this operation a high level of flexibility is offered.

A further advantage of the invention is that by means of a load picking-up means which can be raised and lowered the gantry lift stacker picks up and sets down a container to be set down. This permits precise positioning of the container to be set down with respect to an already set-down container and therefore permits the use of a so-called spreader in twin operation. In order to pick up two containers simultaneously, both containers must be precisely positioned and aligned with respect to each other. A defined distance between the two containers is decisive for the pick-up using a spreader in twin operation. The distance between two containers is 10 to 100 mm, in particular 30 mm.

In accordance with the invention, in the case of a gantry lift stacker, designed as a straddle carrier, for containers, in particular for carrying out a method for the positioning of a gantry lift stacker, having travel supports, travel drives and a controller cooperating therewith, having a load picking-up means for containers which can be raised and lowered, having at least one sensor for positioning the gantry lift stacker and the container to be set down, positioning one behind the other, which permits simultaneous pick-up of two containers is achieved in that at least one sensor is disposed on the gantry lift stacker, by means of which a position of a rear wall of the already set-down container can be determined and the container to be set down can be set down from the gantry lift stacker at a preselected distance behind the set-down container in such a way that, in relation to its longitudinal orientation, the container to be set down is flush with the longitudinal direction of the set-down container.

Such an arrangement of at least one sensor on the gantry lift stacker permits detection of the rear wall of the set-down container. Only then can the gantry lift stacker be positioned at a preselected distance. For example, a position of the sensor on the spreader or the running gear units is possible. It is further preferred that at least two spreader sensors are disposed on the front and rear face of the spreader relative to the forwards travel direction of the gantry lift stacker and at least four outer sensors are disposed on four travel supports of the gantry lift stacker in order to determine the distance and an orientation in the longitudinal direction of the set-down container.

Therefore, by means of the two spreader sensors the position of the rear wall of an already set-down container can be determined in front of or behind the gantry lift stacker relative to the forwards travel direction. The outer sensors on the travel supports additionally permit the orientation of the container to be set down relative to its longitudinal axis to be determined. The container can thus be orientated according to the measurement values supplied by the sensors.

Provision is advantageously made that the spreader sensors for determining the position of the rear wall of an already set-down container are orientated to the ground at a 90° angle, i.e. vertically downwards as seen from the spreader in the travel direction. By means of the vertically downwardly orientated spreader sensors, it is possible to distinguish between the ground and a set-down container and therefore to detect an upper edge of the already set-down container.

A further embodiment in accordance with the invention makes provision that at least four outer sensors are disposed orientated forwards on the front travel supports and orientated rearwards on the rear travel supports relative to the forwards travel direction, and at least four inner sensors are disposed inwardly on travel supports of the gantry lift stacker in order to determine the distance and orientation in the longitudinal direction of the container to be set down.

By means of the outer sensors, which are disposed on the outer ends of the travel supports, the position of the already set-down container or its rear wall is determined. Four inner sensors are used to determine the orientation of the container to be picked up. This sensor arrangement is particularly advantageous for upgrading a gantry lift stacker with already available outer sensors for automatic steering to a gantry lift stacker with automatic steering and automatic orientation of a picked-up container. By supplementation with four inner sensors a precise determination of the position of the container to be picked up is possible and so this container can be orientated relative to the already set-down container.

A further preferred variation of the gantry lift stacker includes at least four outer sensors being disposed at front and rear outer corners of the spreader relative to the travel direction of the gantry lift stacker in order to determine the distance and orientation in the longitudinal direction of the set-down container.

This alternative arrangement of the outer sensors on the spreader likewise renders possible detection of the side walls of an already set-down container or its orientation relative to its longitudinal axis and the extent and positions of its rear wall.

Two exemplified embodiments of the invention will be explained in greater detail hereinafter with reference to drawings.

