Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/2025—Particular purposes of control systems not otherwise provided for
  • E02F9/2029—Controlling the position of implements in function of its load, e.g. modifying the attitude of implements in accordance to vehicle speed
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
  • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
  • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
  • E02F3/434—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/2025—Particular purposes of control systems not otherwise provided for
  • E02F9/205—Remotely operated machines, e.g. unmanned vehicles
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
  • E02F9/221—Arrangements for controlling the attitude of actuators, e.g. speed, floating function for generating actuator vibration
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/2025—Particular purposes of control systems not otherwise provided for
  • E02F9/2045—Guiding machines along a predetermined path
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/2058—Electric or electro-mechanical or mechanical control devices of vehicle sub-units
  • E02F9/2083—Control of vehicle braking systems

Definitions

• the present invention relates to the field of methods for automatic mission management of a work vehicle and in particular of a mission for loading a bucket with bulk material.
• Agricultural or work vehicles are equipped with an arm or lifter and a transmission which has the purpose of allowing the vehicle to be moved.
• the transmission can be driven by a prime mover, usually on internal combustion engine, although in recent years vehicles have been developed in which the prime mover is defined by an electric motor.
• this includes at least two segments, in particular a first segment hinged to the vehicle chassis and a second segment hinged to the first segment.
• the second segment is represented by a bucket or shovel.
• the activation of the different segments is achieved by double-action hydraulic actuators, often controlled by an open-centre hydraulic circuit.
• the hydraulic circuit is powered by a dedicated hydraulic pump driven in rotation by the prime mover.
• the latter therefore, can be both an internal combustion engine and an electric motor dedicated exclusively to drive the hydraulic pump dedicated to supply the arm and hydraulic users.
• the material is moved to be loaded onto trucks, transported or accumulated.
• the loading operation requires a certain commitment for the operator who must acquire some experience in coordinating the movements of the arm with the operation of the vehicle propulsion system.
• the aim of the present invention is to propose a method of automatic management of a loading mission of a bucket of a work vehicle.
• Automatic management of the loading of a bucket must necessarily include a pile breaking phase after the bucket has penetrated the same pile.
• the basic idea of the present invention is to perform a first partial and slow backward rotation of the bucket until reaching a predetermined cutting angle with respect to a support surface and at the same time perform a sudden lifting of the arm until it reaches a predetermined height.
• slow and sudden are related to each other.
• a slow movement means that it takes longer to complete than a sudden movement.
• a slow movement in terms of control of the hydraulic circuit, can mean an opening of the supply valve of the respective actuator by, for example, 30%.
• a sudden movement implies the opening of the valve in a range between 30% and 80%.
• Any bucket has an approximately flat bottom surface.
• the angle of the bucket is therefore calculated between this lower surface and the ground.
• a cutting angle is generally between 30 and 80°.
• the procedure includes a second partial and sudden backward rotation of the bucket until it reaches a predetermined position spaced from a bucket actuation end of run.
• this second rotation causes the portion of material balanced on the external edge of the bucket to fall into it, ensuring optimal filling.
• the vehicle is prepared to transport the material along a path and the combination of the lowering movement of the arm and the rotation of the bucket to the end of its travel induces the excess material to detach, i.e. to fall, from the bucket. This helps keeping the work site clean.
• the detection of the contact of the bucket with the pile can be determined when the pressure measured at the hydraulic actuator associated with the arm or bucket exceeds a first predetermined threshold, which can be absolute or percentage, and at the same time the speed of the vehicle reaches a second speed threshold lower than the first speed threshold.
• a first predetermined threshold which can be absolute or percentage
• the combined monitoring of speed and pressure makes the detection robust, also allowing you to calibrate the processing unit according to the different types of materials that form the pile and depending on the bucket insertion depth you want to achieve in the same phase of approach.
• prime mover can be understood as
• the first pressure threshold measured at the actuator responsible for holding the arm and/or bucket, considered to determine the event of contact of the bucket with the pile is variable as a function of the speed of the vehicle.
• the contact of the bucket with the pile can be detected on the basis of the aforementioned pressure threshold and by monitoring the rotation speed of the prime mover.
• the procedure further comprises
• the cutting configuration of the bucket is such that the lower part of the bucket forms an angle between 30 and 80° with the ground.
• the processing unit is configured to readjust the rotation speed of the prime mover so as to ensure the necessary oil flow to the hydraulic actuators associated with the arm.
• inching is carried out in this phase, i.e. the propulsion is reduced to favour the flow of oil towards the hydraulic functions of actuation of the articulated arm.
• the processing unit is configured to control the service brake, the latter is activated during the breaking phase to limit the vehicle advancement.
• the processing unit is configured to engage reverse gear and possibly deactivate the service brake and return the vehicle to the same point where the setup phase began.
• the present invention concerns a method for automatic management of a bucket BU loading procedure and concerns an ECU processing unit associated with a work vehicle WL specifically configured to perform the management method.
• Fig. 1 shows an example of flowchart including essential and optional steps as described below.
• step 1 the operator, after placing the vehicle in front of a pile BK of bulk material accumulated on the ground, starts the automatic bucket filling procedure.
• step 2 a series of conditions are checked before starting the procedure.
• step 2 C1 Parking brake DEACTIVATED C2 Hydraulic functions ACTIVE C3 Prime mover OPERATING C4 Arm control joystick RELEASED C5 Service brake RELEASED C6 Vehicle speed lower than a predetermined threshold YES C7 Position of the lower bucket at a predetermined height YES C8 Forward gear selection YES
• Condition C1 is intended to check whether the vehicle is not in parked condition.
• Condition C2 is intended to check whether the hydraulic functions are active. In fact, the activation of the various hydraulic users on board is only possible when these are active to avoid, for example, during the movement of the vehicle that they are activated involuntarily.
• Condition C3 is intended to check whether the prime mover is operational. For example, in the case of an internal combustion engine it must be on and at least in low idle, while, in the case of an electric prime mover, the relevant control inverter must be powered.
• Condition C4 has the purpose of verifying whether the operator has released the joystick lever, otherwise, obviously, it is necessary to abort the procedure as the commands given manually take precedence over the autonomous control operated by the processing unit.
• Condition C5 has the purpose of checking whether the operator has released the service brake pedal, as the setup phase involves the automatic start-up of the vehicle.
• Another condition C6 concerns the speed of the vehicle, which must be lower than a predefined threshold that can be set, so that the vehicle does not impact against the pile of bulk material with an excessive and dangerous speed.
• a further condition C7 concerns the position of the bucket, which must be adequate to start the loading operation, in the sense that it must not be excessively high. This condition is present for safety reasons, preventing it from being involuntarily activated when the high and full bucket is, generally, near a truck where emptying the bucket. Furthermore, with this condition it is possible to avoid the risk that the bucket does not have time to reach the correct dig position, pressing downward on the pile. This could cause the vehicle to rear up and overturn with serious risk for the operator.
• the processing unit is configured to select forward gear autonomously.
• step 3 the first phase, setup, is performed, otherwise, in step 4, the interruption/abortion of the automatic procedure is signalled to the operator by indicating the unverified conditions and the system returns to step 1.
• step 5 the correct achievement of the optimal position of the arm is monitored.
• step 7 If during this monitoring step the pressure in the hydraulic cylinder supporting the arm exceeds a predetermined value or the optimal position is not reached promptly, i.e. within a predetermined time interval, then go to step 7, interrupting/aborting the procedure and reporting the interruption to the operator.
• the vehicle's forward speed is monitored and at the same time the pressure in the arm and/or bucket support cylinder.
• the advancement of the vehicle is controlled in an open chain by controlling the rotation speed of the prime mover if thermal or the torque supplied if it is an electric motor.
• step 8 a countdown starts.
• step 9 the detection of contact between the bucket and the pile causes the counter to stop and reset to zero.
• the pressure threshold measured in the bucket support actuator and indicative of the contact of the bucket with the pile is a function of the value of the automatic advancement speed of the vehicle performed in the setup itself.
• FIG. 3 An example of a work vehicle is shown in Fig. 3 .
• This comprises a frame F to which an articulated arm BO, BU is hinged and comprises at least a first segment BO of elongated shape hinged to the frame at a first end and a second end, opposite the first, it supports a second segment which can be the BU bucket.
• a first hydraulic actuator A1 is associated to the first segment, while a second hydraulic actuator A2 is associated to the bucket.
• the actuator supporting the bucket can be understood as both the actuator supporting the first segment and the actuator supporting the bucket with respect to the first segment.
• the arm can comprise further intermediate segments and further respective actuators.
• the vehicle is equipped with an internal combustion or electric prime mover E.
• the prime mover is an internal combustion engine it is defined as a prime mover and is generally connected to a transmission for propulsion of the vehicle and to a hydraulic pump to control the flow of oil which must be sent to the hydraulic circuit for actuating the articulated arm BO, BU.
• the propulsion engine is electric, then it is connected to the vehicle wheels directly or through a gearbox.
• the hydraulic oil is pumped by an electric pump, i.e. a hydraulic pump driven by an electric motor, defined as a prime mover.
• FIG. 2 a further flow diagram is shown indicative of a further portion of the automatic bucket filling procedure.
• the steps indicated in Fig. 2 are a consequence of the detection in step 9 of the contact of the bucket with the pile.
• the penetration phase described above is started.
• the advancement of the vehicle, in the penetration phase is obtained by appropriately regulating the driving torque of the propulsion engine.
• step 11 is performed in which the pressure in the boom lifting cylinder is monitored and at the same time another countdown is launched.
• step 12 When the pressure in the arm lifting cylinder exceeds a second pressure threshold higher than the first or the counter reaches zero then, at step 12, the penetration phase is interrupted, otherwise the cycle continues recursively on step 10.
• the breaking phase begins at step 13.
• the breaking phase begins at step 13.
• Step 13.3 a second partial and sudden backward rotation of the bucket until it reaches a predetermined position spaced from a bucket actuation limit switch.
• step 14 of monitoring the arm configuration is started. This monitoring procedure cycles through step 13 until the arm and bucket are fully implemented as described above.
• the vehicle can be stopped.
• the rotation speed of the prime mover is increased and the hydraulic actuators of the arm are controlled by signals such as to favor impulsive movements of the arm which facilitate the breaking of the material and a better distribution inside the bucket.
• the pressure thresholds of the arm and/or bucket support actuator, the forward speed of the vehicle, the rotation speeds of the prime mover can be grouped into specific sets for each type of material that defines the pile to be recalled, in groups, in the pre-setting phase of this automated procedure.
• the operator can select, via a human/machine interface device, the type of material constituting the pile and in response to this choice, the processing unit selects the values relating to the aforementioned parameters.
• step 15 Preferably, at the end of the breaking phase, step 15, reverse gear is automatically engaged and the vehicle is brought back to approximately the same position in which the present automatic bucket loading procedure was started.
• step 15 includes the following sub-steps:
• the present invention can advantageously be carried out by means of a computer program which includes coding means for carrying out one or more steps of the method, when this program is executed on a computer. Therefore, it is understood that the scope of protection extends to said computer program and further to computer readable means comprising a recorded message, said computer readable means comprising program coding means for carrying out one or more steps of the method, when said program is executed on a computer.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Mechanical Engineering (AREA)
• Operation Control Of Excavators (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=92209140

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Citations (6)

• 2025
  • 2025-05-28 EP EP25179355.0A patent/EP4656809A1/de active Pending

Patent Citations (7)

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