FIELD OF THE INVENTION

The invention is in the field of a cleaning machine for a road or pavement or gutter. These machines are used to remove objects, such as small items, such as leaves, and debris, and dirt from a road or the like, using a broom system for cleaning the road or the like, and typically a storage for removed objects and dirt.

BACKGROUND OF THE INVENTION

The present invention relates to a cleaning machine. A main function of such a cleaning machine is to remove dirt/debris specifically from the gutter (side of the road, edge of the pavement; curb) and to remove it from the street; dirt/debris may be understood to relate to all smaller items being present and to be up-taken. Collecting and removing the debris is typi cally done by means of broom(es) which sweep the debris in a direction of an uptake element, and uptake of the debris then takes place, such as by under-pressure, e.g. vacuum. Figure 1 shows an example of a prior art cleaning machine, wherein brooms, located underneath the cleaning machine and rotating, sweep the dirt/debris towards a suction mouth. The suction mouth is provided with under-pressure, thereby up-taking the dirt/debris into the machine, though a suction tube, towards a container of the machine.

For proper up-taking of dirt/debris an operator, typically the driver of the cleaning ma chine, uses a broom control device to move the brooms towards the dirt and debris, and at the same time steering the cleaning machine, paying attention to traffic and pedestrians, and so on. The broom control device may be a joy stick or the like. The position of the entire ma chine is controlled by the steering controls of the driver, such as a typical steering wheel. It is found that manually and simultaneously controlling all these movements requires a high level of practice, as well as good eye-hand coordination, and concentration. In practice, there are very few operators that are skilled enough to get optimum performance of the system. Lack of accuracy of the above described manual process may have a large impact on quality, effi ciency, and speed of the cleaning work performed. Also, from an ergonomics point of view, the above is a challenging topic to address, as it is physically demanding and technically very complex to solve.

Some documents may be referred to. For instance DE 102017 117013 A1 recites a semi-autonomous following device, having at least one drive apparatus, at least one apparatus for steering the drive apparatus, at least one apparatus for detecting a guidance signal, at least one control unit which activates, as a manipulated variable, the apparatus for steering the at least one drive apparatus, as a function of the guidance signal. According to the invention there is provision that the control unit or a unit which is separate from the control unit acti vates further apparatuses as a function of the guidance signal, wherein the further apparatuses are selected from the group comprising: direction indicator, vehicle lights, machine modules and radio-operated remote-control systems. The interconnection of the apparatuses increases the safety of the locomotion of the following device in the public space and also the efficiency of the cooperation between the machine and the user. CN 103 161 133 A recites a an intelli gent road-cleaning vehicle based on machine vision. The intelligent road-cleaning vehicle comprises a vehicle body provided with a cleaning machine, a first light source, a second light source, an image obtaining device, an image extracting device, an image processing device, a first judging device and an automatic turning device, wherein the image extracting device is used for extracting an image of a targeted area from a road surface image, the image pro cessing device is used for conducting grayscale adjustment and binarization treatment to the image of the targeted area to generate a binary image and covering a two-dimensional array corresponding to the binary image to count the number of elements with values of one in the two-dimensional array, the first judging device is used forjudging whether the number of the elements with the values of one is larger than a preset value, and the automatic turning device is used for sending an order of turning right to the vehicle body when a judging result of the first judging device is yes, and sending an order of turning left to the vehicle body when the judging result of the first judging device is no. The intelligent road-cleaning vehicle is based on the machine vision, is capable of turning and changing speed automatically, and has a value of actual popularization. CN 103 696381 A recites a control method, a control device, a control system and a sweeping vehicle for road edge cleaning. The control method com prises the following steps: obtaining the distance between a sweeping device and a road edge in real time according to the information of the road edge; when the distance between the sweeping device and the road edge exceeds a preset range, sending out a control command so as to adjust the position of the sweeping device, so that the distance between the sweeping de vice and the road edge is always in the preset range so as to ensure that the sweeping of the road edge is efficiently completed, avoid collision with the road edge, reduce the working dif ficulty of operators and improve the work efficiency. WO 2020/144011 Al, which is pub lished after the present priority date, recites a method for operating a cleaning vehicle, in par ticular a road sweeper which can be operated in an automated manner, by means of a control device, wherein a trajectory is calculated and control commands for longitudinal guidance and lateral guidance of the cleaning vehicle when driving along the calculated trajectory are gen erated, measurement data are received from at least one sensor for determining a cleaning area, and at least one actuator for positioning a cleaning apparatus of the cleaning vehicle for cleaning the cleaning area is controlled in the longitudinal direction and/or transverse direc tion relative to a direction of travel of the cleaning vehicle on the basis of the received meas urement data. A control device, a computer program and a machine-readable storage medium are also disclosed.

The present invention therefore relates to an improved cleaning machine, and a pave ment track system, which overcome one or more of the above disadvantages, without jeopard izing functionality and advantages.

SUMMARY OF THE INVENTION The present invention relates in a first aspect to a cleaning machine (1) for a road or pavement or gutter comprising a vehicle (2), the vehicle comprising at least one vertically and horizontally movable broom system (3), a controller (4) for moving said broom system, and optionally a display (5) for viewing a position of the at least one broom system, character ized in a pavement track system (6) comprising a 3D camera (7) providing 3D-images, pattern recognition software adapted to process the 3D-images, wherein the pattern recognition soft ware identifies a side of the road, and wherein the pattern recognition software measures a distance from the vehicle to the side of the road, and wherein the controller is adapted to move the broom-system and preferably also the vehicle sideways such that a distance between the broom system and side of the road is controlled. The at least one vertically and horizon tally movable broom system is typically provided on a right side of the cleaning machine in countries where vehicles drive at a right side of the road, or in the alternative on the left side. A second broom may typically be provided at the other (left or right) side. So each broom sys tem may comprise one broom, two brooms, or more than two brooms, such as three brooms. Therewith significant improvements are achieved. By implementing a 3D camera, image recognition and connecting it to the described machine control functions, the above described functions are automated during a significant part of the operating/cleaning process. A reliable, automated broom positioning system is found to have a positive effect on quality, efficiency, speed and ergonomic aspects of the work performed. A reliable recognition of the curb is pro vided, by ignoring the dirt (to be removed) visible in the image, compensating for broom- wear, and adapting for difficult image situations (high contrast, low light, etc.). Added value of the system is found in a lower strain, stress, and fatigue for the operator during significant part of the operation, both physical (ergonomics, repetitive movements, sitting position) and psychological (concentration, fatigue), a better and more constant quality of work, i.e. better and more efficient cleaning, and no declining of quality by loss of concentration or distraction of the operator. Further it is found that past experience of the operator has less or no influence on the quality of the work. In addition, an improved traffic security is provided, as the opera tor can pay more attention to traffic, pedestrians and other surroundings. Typical components of the present pavement track system are a 3D camera, image recognition software + hard ware, including a connection to machine control functions. The image recognition software used may be Open Source software. The software is taught to detect the curb. Electronic con trol of at least one broom side-shift is provided, as well as electronic control of vehicle steer ing (including manual override safety). Some main software steps may be acquisition of a 3D image from the camera, a translation of the 3D-image to a 2D image, a determination of a “rising edge” or “falling edge” in the 2D image, representing the curb, identifying at least 3 points on the “rising edge”/”falling edge” and thereby validating a line representing the curb on reliability, such as by calculation a standard deviation, establishing if these at least 3 points are reliable for at least 2 consecutive frames/images and then accepting the representation of the curb, and further, when accepted, these points are sent to a machine control such as via CAN, to initiate the required control actions. It is found that the identification of the falling edge, i.e. an upper edge of a curb, provides more reliable and reproduceable results. The edge is preferably determined ahead of the machine, in the direction of movement, such as 0.5-3 m ahead of the machine, e.g. 1-2 m. As the speed of the cleaning machine is known, the speed of the machine, and the measured distance of the broom from a curb, can be used to move the brush-system towards or from the curb when advancing. Typically positioning of the can be done by moving the broom-system and/or vehicle sideways such that a distance between the broom system and side of the road is controlled. The vehicle control can at least partly by overtaken by an automated system, in view of the present hydraulic system, such as an or- bitrol. The automated system can perform relatively simple tasks, such as positioning of the cleaning machine, driving, steering, and somewhat more complex tasks, as recognition of ob stacles and human beings, especially in front of the machine. In view of the limited speed of the cleaning machine such an automated system could already be sufficient.

For improved range and added functionality, an option is to use the third broom sys tem. This option provides an increased sweeping width/range and is often used with a dedi cated broom for weed removal. Operating this third broom typically has similar requirements as the first and second brooms: it may be too far from the curb and thereby dirt/debris is missed/not picked up, it may be too close to the curb and the wires of the broom are pushed flat, the broom does not move the dirt effectively. Operation of the third broom may be done by a second joystick, in addition to the standard controls. For the operator this implies operat ing two joysticks simultaneously; operating/movement of this 3rd broom is very frequent. The construction of the third broom is typically similar to the first and second broom system: the position of the third broom relative to the machine, controlled by the so-called “third broom side-shift”, this is a linear movement, perpendicular to the length axis of the machine (driving direction). And the distance between the machine itself and the curb is controlled.

In a second aspect the present invention relates to a pavement track system computer program comprising instructions for operating the Cleaning machine (1) according to one of the claims 1-11, the instructions causing the computer (1) to carry out the following steps: loading 3D images, identifying the pavement; determining a distance between the broom sys tem and pavement; and maintaining said distance within predetermined limits by moving said broom system by means of the controller sideways.

Thereby the present invention provides a solution to one or more of the above-men tioned problems.

Advantages of the present invention are detailed throughout the description.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates in a first aspect to a cleaning machine according to claim 1.

In an exemplary embodiment of the present cleaning machine the controller may adapt the distance in view of broom wear.

In an exemplary embodiment the present cleaning machine may further comprise a sec ond broom system, and optionally a third broom system.

In an exemplary embodiment of the present cleaning machine the software may adapt for shadow effects.

In an exemplary embodiment of the present cleaning machine the software may adapt for contrast.

In an exemplary embodiment of the present cleaning machine the software may be trained for recognizing the pavement, such as for identifying a rising edge thereof (curb).

In an exemplary embodiment of the present cleaning machine the software may be adapted to validate a position of the rising edge, such as by validating if at least three identi fied points of the rising edge have a linear relationship (are on one line).

In an exemplary embodiment of the present cleaning machine the rising edged may be validated on at least two consecutive 3D-images, and combinations thereof.

In an exemplary embodiment of the present cleaning machine the control may be elec tronic.

In an exemplary embodiment of the present cleaning machine a CAN-bus may be used for control.

In an exemplary embodiment of the present cleaning machine the controller may be adapted to be manually over-ride.

In an exemplary embodiment of the present cleaning machine the controller may be adapted to maintain the distance between the broom system and side of the road at a constant value within a predetermined limit.

In an exemplary embodiment of the present cleaning machine an orientation of the 3D- camera may be adaptable, such as adaptable to be oriented substantially towards a side of the road.

In an exemplary embodiment of the present cleaning machine the 3D-camera may be adaptable to be in a height position providing images of the side of the road.

In an exemplary embodiment of the present cleaning machine brooms may be adapted to sweep debris and dirt to a suction point, such as by rotating.

In an exemplary embodiment of the present cleaning machine brooms may be adapted to move with respect to the cleaning-machine in a horizontal direction and/or vertical direc tion, preferably move each individually, and preferably move independent in the horizontal and vertical direction.

In an exemplary embodiment of the present cleaning machine the cleaning machine may comprise a suction system for up-taking debris and dirt from the suction point, such as an en larged suction opening, connected to the suction opening a suction tube, at the other end of the suction tube a container for receiving dirt and debris, and a fan for providing suction, such as by under-pressure, e.g. a centrifugal fan. In an exemplary embodiment of the present cleaning machine the cleaning machine may comprise at least one ventilation opening, and an outlet, preferably comprising a filter for re moving small particles.

In an exemplary embodiment of the present pavement track system may further com prise instructions for recognition of a curb, and/or neglecting the dirt/debris to be removed visible in the image, and/or compensating for broom-wear, and/or adapting for difficult image situations, such as high contrast, and low light.

The invention is further detailed by the accompanying figures and examples, which are exemplary and explanatory of nature and are not limiting the scope of the in vention. To the person skilled in the art it may be clear that many variants, being obvi ous or not, may be conceivable falling within the scope of protection, defined by the present claims.

SUMMARY OF THE FIGURES

Figure 1 show an exemplary embodiment of the present machine.

Figures 2a-b show a third broom system.

Figures 3a-d show operational aspects of the present cleaning machine.

DETAILED DESCRIPTION OF THE FIGURES In the figures:

1 Cleaning machine

2a first right hand broom

2b optional second left hand broom

2c optional third broom

3 suction mouth

4 suction tube

5 container

6 filter

7 outlet

8 suction fan

9 side shift

10 3D camera

Figure 1 show an exemplary embodiment of the present machine.

Figures 2a-b show a third broom system, indicated with a circle.

The figures are further detailed in the description and examples below.

The present cleaning machine takes over a significant part of the manual control of sev eral functions of the sweeper, during sweeping operation. This reliefs the driver of a difficult, tiring task.

In an example the present modification is designed and integrated in the sweeper, leav ing all existing/present functions of e.g. the Ravo type 5 machine otherwise unchanged. Con- trolling these functions can still be performed manually, but also an automatic mode is availa ble.

The present sweeper, or streetsweeper, can best be described as a large domestic vac uum cleaner. All typical components of a vacuum cleaner are typically there: an engine driv ing a (centrifugal) fan that creates vacuum, thus creating air movement in a suction nozzle that picks up dirt/debris. Through a (suction)tube the airflow transports the dirt/debris into the dirt/debris container (See figure 1). To be able to work on a road surface, the machine typi cally meets a number of road-specific requirements: (i) it provides sufficient cleaning width: as the width of the suction nozzle is typically only 30 cm, this is too narrow to deliver effi cient cleaning. To increase the cleaned surface width, brooms are added, that move dirt/debris from both sides (L+R) to the center of the machine, where the suction nozzle is located (See figure 1); (ii) as a standard two brooms (L+R) are typically provided, which result in a total sweeping width of approximately 2 meters; (iii) an optional third 3rd broom is provided for an increased width with approximately 70 - 90 cm extra. It also provides an increased flexibility to reach into comers and other hard to reach areas (iv) As the brooms typically use a certain force on the ground, that is kept more or less constant, independent from shape of the road- surface, speed-bumps and broom wear (a worn broom weighs less than a new one)

This load-regulating system is based on a spring-loaded mechanism; (v) The brooms are best kept in a rather precise position relative to the side of the road and/or curb to function properly; when they are too far from the curb dirt/debris may be missed, when they are too close to the curb hairs/wires from the broom may be pushed flat to the surface, and the broom may not work properly. This relative position is typically determined by two factors: The po sition of the entire machine; this may be controlled by the driver/operator, steering the ma chine towards- or away from the curb (normal/standard steering function of the vehicle); The position of the 2 standard brooms, relative to the machine; to provide easy, fast position changing of the brooms, vertically and horizontally movable broom system onto which these brooms are preferably mounted on a sub-frame (“broom carriage”) that can move sideways (perpendicular to the driving direction of the vehicle); this system is called “side-shift” and enables the brooms to be positioned closer or further away to the curb. This side-shift, and the relative position of the broom with respect to the machine is controlled with a sensor, the sen sor measuring the relative position and capable of adapting the relative position. This move ment is controlled by hand, with a controller, by the operator. Electrical signals from the joy stick (part of the controller) are connected to the computer controlling the machine (PLC); this PLC in its turn sends electrical signals to the hydraulic valves (operator, joystick). The physical movement of the entire broom carriage is typically powered by a hydraulic cylinder (See figure 1); (vi) The principle of operating the 3rd broom is identical to that of the standard brooms, but it is mounted on a separate frame and thus able to function independent from the standard brooms (See figures 2a and 2b).

The above describes functionality of the present sweeper, relating to proven Ravo 5 technology.

The integration of the present invention into the Ravo 5 machine may be done mainly electrically, such as through software, or by adding an electrical function to an existing (hy draulic) component. An example of the latter is an additional, electrically controlled steering function. This allows the electronic machine control to influence the mechanical/hydraulic steering unit, thus creating automated steering.

Addition of the 3D camera to the machine, creating a 3D image to determine the dis tance between the machine and the curb, by image recognition, and bring this information with respect to the distance to the control -computer of the machine, allows the introduction of an automatic sweep function, relieving the driver of a tiring task, creating better efficiency, and more safety.