Operating vehicle with safety sensor

The present invention relates to a loading vehicle provided with lifting forks.

In particular, the invention relates to a loading vehicle provided with lifting forks, arranged to be inserted below an object to be transported, and to lift and lower the object as a function of the loading/unloading and transport operations to be carried out.

The invention finds particularly advantageous use in self-driving loading vehicles, for example AGV or LGV.

In general, self-driving loading vehicles are provided with numerous safety sensors, designed to detect the presence of obstacles along the path followed under the control of the self-driving system.

The safety sensors are connected to a vehicle control module which, in the presence of an obstacle, stops the vehicle or temporarily diverts the trajectory thereof. Obviously, the main purpose and function of the safety sensors is to prevent the vehicle from accidentally hitting an obstacle or an operator.

In loading vehicles provided with lifting forks, a safety sensor is provided positioned in an area of the vehicle close to the fork, so that the sensor faces the area of action of the fork itself. For example, the safety sensor is located in a substantially intermediate position to the forks and in a lower area of the vehicle. The purpose of the safety sensor is to detect the presence of people or objects positioned in the operating area of the forks, in particular in the steps in which the vehicle approaches an object, to insert the forks below the object.

In the current vehicles, the safety sensor is located in a fixed position. The safety sensor is functional and effective during all the steps of movement of the vehicle, empty or in the presence of a load supported by the forks, with the exception of a particularly critical step within the cycle of operations normally carried out by the vehicle. Such a critical step is the step during which the vehicle approaches an object to bring the forks below the object, so as to allow the lifting and transportation thereof. During such a step, it is in fact necessary to disable the safety sensor.

The need to switch off the safety sensor is due to the following operating modes of the vehicle.

During the steps of movement of the vehicle, both empty and with a load on board, the forks are located in a maintenance position, at a certain height from the ground, to avoid jamming. To be inserted below an object to be lifted, the forks must complete an initial movement which comprises a descent to ground level, starting from the maintenance position placed at a higher height. Such an initial movement brings the forks inside the detection space of the safety sensor, which must therefore necessarily be switched off to prevent the control module from stopping the vehicle.

In the current vehicles, the entire step during which the forks are inserted below the object to be lifted therefore occurs without the supervision of the safety sensor and the vehicle control module. This means that an operator or a foreign object which is unexpectedly located between the vehicle and the load during the insertion of the forks below the load would inevitably be hit and/or crushed between the vehicle and the load.

The object of the present invention is to solve the considerable safety defect of the current vehicles.

An advantage of the vehicle according to the present invention is that of substantially allowing the operation of the safety sensor during the step of inserting the forks below the object to be loaded.

Additional features and advantages of the present invention will become more apparent from the following detailed description of an embodiment of the invention in question, illustrated by way of non-limiting example in the appended figures, in which:

- figure 1 shows an isometric view of an operating vehicle according to the present invention;

- figures 2, 3 and 4 show a side view of the vehicle according to the present invention, at different steps of approaching an object (O) to be picked up; some parts of the vehicle have been removed to better show others.

The operating vehicle according to the present invention comprises a self- propelled unit (10), structured to move on a movement surface along a main direction (X), following a given path.

The self-propelled unit (10) is substantially the part of the vehicle responsible for movement. The self-propelled unit (10), known in the art, essentially comprises a motor, a plurality of wheels, of which at least one connected to the motor by means of a transmission system, and a steering system, arranged to allow the self-propelled unit to follow straight trajectories and curved trajectories. The self-propelled unit (10) has an operating part (11 ). In the depicted, preferred but not exclusive embodiment, the self-propelled unit comprises two wheels (12), positioned below the operating part (11 ), and a steering wheel (13), positioned below the self-propelled unit (10) in an area opposite the operating part (11 ). The steering wheel (13) is a driving wheel and is rotatable about a vertical axis. The steering system with which the self-propelled unit (10) is provided operates by implementing the controlled rotation of the steering wheel (13) around the respective vertical axis, in a manner known in the art.

The vehicle according to the present invention further comprises a fork (20), associated with the operating part (11 ) of the self-propelled unit (10). The fork (20) is vertically movable between a lower position and an upper position. In the lower position, the fork (20) can be inserted below an object to be loaded on board. Typically, in the lower position the fork (20) is close to the ground. The distance from the ground is suitable to allow the insertion below the object to be loaded on board. For example, the height from the ground of the fork (20) in the lower position is suitable to allow the insertion below a standardised pallet. The upper position of the fork (20) is located at a certain height from the ground, in relation to the size and overall weight of the vehicle and the objects to be loaded, and the maximum height at which the objects are envisaged to be unloaded or picked up.

In a possible embodiment of the vehicle, the operating part (11 ) is arranged in a rear area of the vehicle, i.e., an area which, during most of the movements, faces backwards with respect to the advancement direction of the vehicle. In such a case, the vehicle normally travels with the fork facing backwards, except for the steps in which the vehicle must pick up an object. In these steps, the vehicle moves in reverse, with the fork facing the object to be picked up.

In another possible embodiment of the vehicle, the operating part (11 ) is instead arranged in a front area of the vehicle, i.e., an area which, during most of the movements, faces forwards with respect to the advancement direction of the vehicle. In such a case, the vehicle normally travels with the fork facing forwards, including the steps in which the vehicle must pick up an object. In these steps, the vehicle moves forwards, with the fork facing the object to be picked up.

In the following description, reference will be made to a forward displacement or movement, meaning by this a displacement or movement in which the operating part (11 ) faces backwards, i.e., faces in the direction opposite to the advancement. The self-propelled unit (10) is however capable of moving even in reverse, i.e., in the opposite direction, turning the operating part (11 ) forwards with respect to the advancement direction. The loading manoeuvres of an object (O) are substantially carried out in reverse.

The self-propelled unit (10) further comprises a frame, arranged to support the components mentioned above and other components of the vehicle which will not be described in detail, since these are components known in the art.

In the embodiment depicted, known in the art, the fork (20) comprises a pair of arms (21 ) parallel to each other and substantially horizontal, which protrude from the vehicle away from the operating part (11 ). Such arms (21 ) are intended to be inserted below the object to be loaded. The arms (21 ) lie on a substantially horizontal plane.

The fork (20) is associated with a movement structure, provided with guides (20a) and actuators arranged to allow vertical translation of the fork (20). Preferably, the movement structure is also arranged to allow translation of the arms (21 ) towards and away from each other, along a horizontal direction perpendicular to the main direction (X).

In the embodiment depicted, which is preferred but not exclusive, the fork

(20) is associated with a first support (22). Such a first support (22), in turn, is connected to a second support (23), with the possibility of sliding along a horizontal direction perpendicular to the main direction (X) by means of a guide system of known type. In particular, the first support (22) allows the sliding of each arm (21 ) towards and away from the other arm

(21 ). The second support (23) is connected to the operating part (11 ) of the self-propelled unit (10) with the possibility of sliding along a substantially vertical direction, by means of a system of guides of known type. First motor means, known in the art, are arranged to slide the first support (22) with respect to the second support (23). Second motor means, known in the art, are arranged to slide the second support (23) with respect to the self-propelled unit (10). The first and the second motor means can be activated, in a known manner, by a control module of the vehicle. Such a control module will be described in more detail in the following description.

The vehicle according to the present invention further comprises a detection sensor (30), provided with a detecting field (R) facing the fork (20), i.e., facing the space occupied by the fork (20). In other words, the detecting field (R) faces the space near the operating part (11 ) of the self- propelled unit (10). In practice, the detecting field (R) is arranged so as to intercept obstacles, such as objects or people, which may be located in front of the vehicle, i.e., along the path followed by the vehicle during a movement facing the direction of the fork (20). The detection sensor (30) is arranged to emit a detecting signal if an object is inside the detecting field (R).

The detection sector (30) is a component well known in the sector, therefore it will not be described in more detail. For example, the detection sensor (30) is a PLS-type sensor.

The vehicle according to the present invention comprises a control module, connected to the self-propelled unit (10) and to the detection sensor (30).

As is well known in the art, the control module mentioned in the present description and in the following claims is generically referred to as a single unit, but can in fact be provided with distinct functional modules (memory modules or operating modules), each responsible for controlling a given device or cycle of operations of the vehicle. In essence, the general control module can consist of a single electronic device, programmed to carry out the functions described, and the various functional modules can correspond to hardware components and/or software routines being part of the programmed device. Alternatively, or additionally, such functions can be performed by a plurality of electronic devices over which the aforesaid functional modules can be distributed. The units can further rely on one or more processors for the execution of the instructions contained in the memory modules.

The control module is connected at least to the following components of the vehicle, so as to control the activation and/or operation thereof: to the motor of the self-propelled unit (10), to said first and second motor means which determine the movement of the fork (20), to said steering system of the self-propelled unit (10), as well as to a possible braking system of the vehicle. The control module could also regulate the operation of other known components of the vehicle, by means of special connections.

In particular, the control module is arranged to control a safety manoeuvre of the self-propelled unit (10) in the presence of a detecting signal of the detection sensor (30). For example, in the presence of a detecting signal emitted by the detection sensor (30), the control module is arranged to stop the vehicle's motor and/or to brake the vehicle itself, using control algorithms known in the art. Furthermore, the control module is arranged to guide the self-propelled unit (10), acting at least on the motor of the self- propelled unit (10) and on the steering system, along a path defined by means of one or more operating algorithms, configured in a known manner to respond to movement and/or collection needs of objects (O) within a plant or an operating area, such as a warehouse, a production plant or other.

Advantageously, in the vehicle according to the present invention, the detection sensor (30) is movable between a first position and a second position.

In the first position of the detection sensor (30). shown in figures 1 , 2 and 3, the detecting field (R) does not intercept the fork (20), in any position adopted by the fork (20) between said lower and upper positions. In other words, in the first position, the detecting field (R) substantially never intercepts the fork (20), i.e., the fork (20), moving between the lower position and the upper position, never enters the detecting field (R), even partially.

Preferably, in the second position shown in figure 4, the detection sensor (30) is disabled or turned off.

The possibility for the detection sensor (30) to assume a first position, in which the detecting field (R) does not intercept the fork (20), in any position adopted by the fork (20) between said lower and upper positions, brings notable progress with respect to the current vehicles. In fact, the detection sensor (30) can be kept active during the entire step of approaching the vehicle to the object to be picked up, i.e., during the entire step in which the fork (20) is inserted below the object to be picked up.

In particular, the collection of an object, i.e., the loading of an object on board the vehicle, envisages the following steps. After the vehicle has reached a position close to the object, with the fork (20) facing the object itself, the fork (20) is brought to the lower position. Subsequently, the vehicle advances towards the object, progressively inserting the fork (20) below the object until a final position. In the current vehicles, the detection sensor (30) is deactivated throughout this step.

On the contrary, in the vehicle according to the present invention, during this entire step in which the vehicle approaches the object, inserting the fork (20) below the object until the final position, the detection sensor (30), being located in the first position, is kept active. Thereby, if anybody unexpectedly positions itself between the object to be picked up and the vehicle approaching the object, the detection sensor (30) would send a detection signal to the control module which would command an emergency manoeuvre to promptly stop the vehicle.

Preferably, but not necessarily, the detection sensor (30) is moved from the first to the second position in an end section of the approach stroke of the vehicle to the object to be picked up, to prevent the detection sensor (30) from suffering undesired impacts. Preferably, but not necessarily, concurrently or before the movement from the first to the second position, the detection sensor (30) can be deactivated.

In the preferred but not exclusive embodiment depicted, the detection sensor (30) is associated with the operating part (11 ) of the self-propelled unit (10). Preferably, the detection sensor (30) is located in a substantially median position with respect to the arms (21) of the fork (20). In particular, the detection sensor (30) is located in a lower area of the operating part (11 ), so as to effectively detect the presence of obstacles placed on the ground.

Preferably, but not necessarily, the self-propelled unit (10) comprises a pair of wheels (12), associated with the operating part (11 ). The detection sensor (30) is located in an intermediate position between the wheels (12). Preferably, the detection sensor (30) is connected to a support (31) which is slidable along a sliding direction parallel to the main direction (X). The detection sensor (30) is movable between the first and the second position by means of the sliding of the support (31 ) along said sliding direction. Motor means, known in the art, is arranged to activate the sliding of the support (31 ) in the two directions along the sliding direction. Preferably, the motor means of the support (31 ) is connected to the control module and is controlled by the latter.

The vehicle according to the present invention is further provided with a stabiliser (40), overlapping the fork (20) and spaced away from the latter by a variable amount. In particular, the stabiliser (40) is vertically movable towards and away from the fork (20). The function performed by the stabilizer (40) is to position itself above in contact with the object (O) supported by the fork (20), so as to stabilise the position thereof and prevent tipping or falling of the object (O).

The stabiliser (40) comprises a flat frame (41 ) defining a substantially horizontal plane. The flat frame (41 ) is intended to be positioned above in contact with the object (O). Motor means, known in the art, is arranged to actuate the vertical displacement of the flat frame (41 ). A support structure (42), provided with a vertical guide system, is connected to the flat frame (41 ) to support it and guide the movement thereof. In the depicted, preferred but not exclusive embodiment, the support structure (42) comprises a vertical upright (42a) along which a carriage (42b) is sliding, in turn connected to the flat frame (41 ).