WO2022008560A1

WO2022008560A1 - Method for aiding the orientation and adjusting of a work tool and work vehicle for performing the method

Info

Publication number: WO2022008560A1
Application number: PCT/EP2021/068753
Authority: WO
Inventors: Adriano GARRAMONE; Andrea Gravili; Stefano Liberti; Antonio Venezia
Original assignee: Cnh Industrial Italia S.P.A.; Cnh Industrial America Llc; Cnh (China) Management Co., Ltd
Priority date: 2020-07-07
Filing date: 2021-07-07
Publication date: 2022-01-13
Also published as: IT202000016444A1; EP4179159A1

Abstract

Aid method for adjusting the orientation of a tool (TO) with respect to a reference (H, Z) for a working or agricultural vehicle (WL), the method comprising a first step (Step 1) of simultaneously checking that in a first condition (CK1) the speed of the prime mover is lower than a predetermined rotation speed threshold, in a second condition (CK2) the vehicle speed is lower than a predetermined vehicle speed threshold, in a third condition (CK3) an intensity of the command given by means of a control lever is lower than a predetermined intensity threshold, and only when all the conditions (CK1, CK2, CK3) are verified, a second step (Step 2) to show, through a man/machine interface, an angular phase shift (α, β) of the tool with respect to the reference (Z, H).

Description

METHOD FOR AIDING THE ORIENTATION AND ADJUSTING OF A WORK TOOL AND WORK VEHICLE FOR PERFORMING THE METHOD

★ ★ ★

5

FIELD OF THE INVENTION

The present invention relates to the field of work vehicles and agricultural machinery and in particular to the system for aiding the orientation adjusting of a tool such as a 10 fork or shovel.

STATE OF THE ART

US2016312434A1 shows a work machine in which a sensor detects the inclination of the shovel with respect to the 15 relative arm to determine the inclination of the shovel with respect to the horizontal plane and when the angle that is formed is less than a predetermined threshold, the control automatically positions horizontally the shovel.

If, on the other hand, the operator wants to exactly define 20 the position of the shovel, this is very difficult, because often the shovel is not visible from the operator's position .

This problem is even more evident in the mechanical shovels (Loader machine), where the visibility of the shovel or fork 25 is very pour from the driving position of the vehicle.

In addition, the system shown in US2016312434A1 may be inconvenient, as the operator may wish to impose an angle of + /- 1, 2, 3 degrees from the horizontal plane, but the system shown in US2016312434A1 would not allow to achieve 30 this configuration by intervening in an undesired way by forcing the shovel or fork in a horizontal position.

Often, the operator must lean forward to be able to see the position of the shovel, other times, he must get off the vehicle in order to view the correct positioning of the shovel, which does not necessarily have to be perfectly horizontal, therefore it is difficult to implement an automatic control if the control itself does not know the operator's intentions.

It is further worth highlighting that modern work machines are equipped with an instrument panel crowded with controls and warning lights. Often these lights are reproduced via a digital display that shows a lot of information. The applicant initially hypothesized to dedicate a portion of the display to constantly show the position of the shovel or fork with respect to the longitudinal axis of the vehicle. This solution has been discarded because the display appears too crowded and difficult to understand, especially when the operator is focused on the machine operations. In fact, it must be taken into account that the work machines are extremely dangerous, therefore it is important or even essential to avoid distractions for the operator with an excess of information reproduced on the instrument panel.

If not specifically excluded in the detailed description that follows, what is described in this chapter is to be considered as an integral part of the detailed description.

SUMMARY OF THE INVENTION

The purpose of the present invention is to make the orientation of a shovel or fork of a work or agricultural vehicle simpler and more comfortable, avoiding as far as possible to avoid an excess of information to the operator. The basic idea of the present invention is to monitor some operating conditions which indicate the willing of the operator to want to finely adjust the position of the shovel or fork and when these conditions are satisfied, then it is shown on a display or by means of luminous points, the angle formed by the fork or shovel with respect to the longitudinal axis of the vehicle. When these conditions are not further verified, the above information is inhibited.

In other words, the information about the angle of the shovel or fork with respect to the longitudinal axis of the vehicle is shown only while the aforementioned operating conditions are met and therefore is hidden when these operating conditions are not met.

For convenience, in the following of this description we speak of "help function", meaning the functionality of aiding the operator to adjust a desired orientation of the shovel or fork with respect to the longitudinal axis of the vehicle or other settable reference.

For convenience, "reference" means a "reference system".

When the aid function is active, the display indicates positive and negative angles of the fork or shovel with respect to the longitudinal axis of the vehicle or other reference .

According to a preferred variant of the invention, the vehicle can be equipped with a sensor for inclining the longitudinal axis of the vehicle with respect to a horizontal plane.

The sensor can be of a different nature, for example a mercury sensor, or an at least monoaxial gyroscope. In this case, the operator can obtain the representation of the angle formed by the shovel or fork with respect to the aforementioned horizontal plane rather than with respect to the longitudinal axis of the vehicle. A button on the dashboard, or a setting menu identifiable by the display allows to select the reference for comparing the angle formed by the shovel or fork to display.

A plurality of sensors, known per se, allow to obtain the angular position of the shovel or fork with respect to the reference. For example, angle sensors allow to identify the inclinations of each kinematic element that connects the fork or shovel to the vehicle chassis in a mobile way.

It is worth highlighting that the position of the actuator is different if the shovel is associated with the arm rather than the fork. This implies that the angle calculation system must be able to know the type of tool connected to the arm of the work vehicle.

This recognition can be automatic or it can be given manually by the operator by means of a specific button or by means of a setting menu identifiable by means of the display which allows to select the tool currently connected to the vehicle arm.

Generally, the actuation speed of the hydraulic actuators of a work machine depends on the speed of the prime mover, because the flow rate of the hydraulic pump that feeds the hydraulic actuators depends on the rotation speed of the prime mover. The accelerator lever, therefore, is often used to speed up the response of the actuation of a vehicle hydraulic actuator.

A first operating condition monitored for the present purposes is the rotation speed of the prime mover.

A second operating condition monitors the vehicle speed, which must be lower than a predetermined vehicle speed threshold.

A third monitored operating condition is the intensity of the tool orientation command, generally imparted by tilting a control lever, which must be less than a command intensity threshold . According to the present invention, the simultaneous verification of the above three operating conditions indicates the intention of the operator to carry out a fine adjustment of the tool. The term "tool" generally identifies a shovel or a fork. According to a further preferred embodiment of the invention, a fourth operating condition is monitored, namely the angle, positive or negative, of the tool with respect to the reference. If this angle is within a predetermined range, this indicates that the operator tries to fine tune the orientation of the tool in order to place it parallel to the reference, i.e. with zero shift angle.

When this further operating condition is satisfied, then, in addition to showing the angle of the tool with respect to the reference, a further visual and/or acoustic signal is produced, for example, the indication of the angle flashes and/or a sound is played.

The angular interval in which this additional functionality is activated is therefore "straddling" the reference.

The angular range in which this additional functionality is activated is therefore "straddling" the reference, be it the longitudinal axis of the vehicle or the horizontal plane, "straddling" means that the angular interval includes the angle of parallelism of the shovel or pitchfork with the reference. Preferably, straddling means that the angular interval is centered on the horizontal plane.

According to a preferred embodiment of the invention, the system object of the present invention detects the intention of a fine adjustment of the tool position when

The rotation speed of the prime mover is below a predetermined threshold, and when at least one of the following additional conditions is verified: - The vehicle speed is below a predetermined threshold

- the command actuation intensity of the tool is below a predetermined intensity threshold.

Furthermore, when the tool orientation is in a predetermined angular range straddling the reference orientation, then the system enables a visual and/or acoustic signal, for example similar to that of the parking sensors with an intermittent buzzer that becomes continue when reaching the condition of parallelism with respect to the reference.

Generally, the tool orientation control lever is a joystick which identifies a natural or release position and an inclination forward and backward. The intensity of the control may depend on the inclination of the joystick lever with respect to the natural position.

According to a preferred embodiment of the invention which combines with any of the variants described above, the system also takes into account the position of the arm, i.e. those positions where the tool is poorly visible. For example, it can be foreseen that when the arm is raised beyond a certain angle, the system inhibits the functionality of fine adjustment aid for the angular position of the fork or loader.

It is clear that as the operating conditions to be satisfied increase, the system tends more to inhibit the display of the angle formed by the tool with respect to the reference, thus limiting the risk of distraction for the operator.

The present invention also relates to a loader and preferably a wheel loader. The dependent claims describe preferred variants of the invention, forming an integral part of this description.

BRIEF DESCRIPTION OF THE FIGURES

Further objects and advantages of the present invention will become clear from the following detailed description of an embodiment thereof (and of its variants) and from the annexed drawings given purely for explanatory and non limiting purposes, in which: Figure 1 shows an example of a working vehicle configured according to the present invention;

Figures 2 - 3 show flow diagrams relating to corresponding examples of preferred implementations of the present invention,

Figure 4 shows a display indicating a phase angle between a tool and a reference;

Figure 5 shows the display of Figure 4, which shows the selection procedure of the tool currently connected to the arm.

The same numbers and the same reference letters in the figures identify the same elements or components or functions .

In the context of this description, the term "second" component does not imply the presence of a "first" component. These terms are indeed used as labels to improve clarity, having no ordinal meaning unless it is clear from the text that there is a precise order to be fulfilled.

The elements and characteristics illustrated in the various preferred embodiments, including the drawings, can be combined with each other without, however, leaving the scope of the protection of the present application as described below. Detailed description of preferred embodiments

According to the present invention, a work vehicle WL such as a mechanical loader, preferably wheeled (wheel loader) comprises a frame F, a prime mover E which rotates a hydraulic pump which allows to pressurize a hydraulic circuit which allows to control one or several actuators A1,

A2 for the movement of an arm B, having a first end hinged to the frame and a second end to support a tool T, such as a shovel or forks etc .. Obviously, each tool has its own load TO axis. The load axis, known per se, is the one that allows the loader to load material, while for a fork, it allows to get on a pallet platform. The vehicle is associated with its own longitudinal axis Z, which is horizontal when the vehicle is supported by a horizontal plane H.

Obviously, if the vehicle is arranged on an uphill or downhill slope or simply on uneven ground, the longitudinal axis may not be horizontal.

Therefore, the longitudinal axis of the vehicle defines a first reference.

The vehicle can be equipped with sensors that allow to know a horizontal orientation H regardless of the orientation in space of the vehicle and therefore of the relative longitudinal axis.

Gyroscopic sensors allow to know the horizontal orientation. Each node or hinge of the arm is associated with another sensor, directly or indirectly which allows to know an angular position with respect to the vehicle, for example with respect to the longitudinal axis of the vehicle.

The vehicle is equipped with a processing unit capable of calculating the angular position of the tool with respect to the reference based on the angle of each node or hinge. These are known techniques.

In the case of the vehicle in figure 1, the arm is defined by a single component, therefore only two angular sensors are necessary to know the angular position of the tool with respect to the reference. The same result can be obtained by measuring the excursion of the hydraulic actuators. In any case, for the purposes of understanding the present invention, their purpose is to return a relative angular position, respectively between the vehicle and the arm and between the arm and the tool in order to be able to calculate the angular position a, b of the axis TO with respect to the reference respectively Z, H, i.e. longitudinal axis and horizontal plane.

Other sensors generally present in vehicles are

A prime mover speed sensor, that is the prime mover rotational speed; generally it is the so-called phonic wheel;

- A vehicle speed sensor which is generally associated with a transmission shaft having a fixed transmission ratio with a vehicular wheel;

- An angle sensor associated with the lever that controls the tool actuator A2 and in particular the angle formed by the tool with respect to the arm; generally it is a joystick .

According to the present invention the following steps are carried out

+ a first step, Step 1, to verify at the same time that:

CK1 the speed of the prime mover is lower than a predetermined rotation speed threshold,

- CK2 the vehicle speed is below a predetermined vehicle speed threshold,

- CK3 an intensity of the actuation command given by means of a control lever is lower than a predetermined intensity threshold, and only when all conditions CK1, CK2, CK3 are verified at the same time is it executed

+ a second step, Step 2, to show, through a man / machine interface, an angular phase shift , b of the tool T with respect to the reference Z, H.

Figures 4 and 5 show a display, preferably a touchscreen that allows to view the angle of the tool TO axis with respect to the reference Z, H. In particular, the display is arranged to indicate a positive or negative numerical value corresponding to the angular phase shift of the tool, that is of the relative TO axis, with respect to the reference or a set of pilot lights accompanied by labels arranged to indicate said angular phase shift.

The man/machine interface includes an intermittent acoustic signal whose frequency is greater the lower the modulus of the angular phase shift of the tool with respect to the reference and in which said sound is continuous when said angular phase shift is zero.

Obviously, other combinations of sounds, frequencies, etc. can be identified to help the operator recognize the approach of the parallelism condition of the tool with respect to the reference. Preferably, the intermittent sound is enabled only when the angular phase shift is less than a predetermined threshold CK4 or when a special command is enabled via the man/machine interface .

The reference can be selected to coincide with the longitudinal axis Z of the vehicle or with a horizontal plane H through the man/machine interface. For example, through the display it is possible to enter a special menu to make customizations, including the reference system to which it is desired to be helped to identify the tool parallelism.

Preferably, the first step, Step 1, further comprises checking CK5 that the arm is below a predetermined height.

In some circumstances it is particularly advantageous when the front of the vehicle obstructs the operator's vision of the tool.

According to a preferred variant of the invention, it is possible, Step 3, to preliminarily set the type of tool TO connected to the arm B, such as a shovel or a fork, and a consequent, Step 4, to modify the calculation of the angular displacement in function of the type of tool selected.

This setting can be manual by means of the man / machine interface means, but it could also be automatic, for example by means of a suitable magnetic sensor located on the second end of the arm.

Figure 5 shows an example of a list of tools that can be selected manually using the aforementioned touchscreen For this purpose, with the acquisition of a new tool, it may be necessary to carry out a preliminary calibration procedure, Step 5, comprising

- adding a new tool to a list of tools,

- adjustment of said first and/or second actuator until a configuration is identified in which said tool results in a zero phase shift angle with respect to the reference,

- recording of said zero phase shift condition to identify the constraints of the kinematic chain defined by the arm and the tool as a whole.

This procedure corresponds to imposing a constraint between the angles of the kinematic mechanism useful for the algorithm for calculating the angular position of the tool with respect to the reference.

Figure 2 schematically shows the first step, Step 1, with the main checks CK1 - CK3 and the optional checks CK4, CK5. Figure 3 shows in dashed form the further preliminary and optional steps 3 - 5.

According to the present invention, the working or agricultural vehicle comprises an arm B having a first end hinged to the vehicle and a second end hinged to the tool, a prime mover E, a hydraulic pump (not shown) suitable for being guided in rotation by the prime mover and feeding at least a first actuator A1 adapted to adjust an angular position of the arm with respect to the vehicle, and a second actuator A2 adapted to adjust an angular position of a tool with respect to the arm, processing means configured to check at the same time that:

- CK2 the vehicle speed is below a predetermined vehicle speed threshold,

CK3 an intensity of the command given to control the second actuator, by means of the control lever, is lower than a predetermined intensity threshold, and only when all the conditions CK1, CK2, CK3 are verified, the processing means are configured to show, through a human / machine interface, an angular phase shift , b of the tool with respect to the reference Z, H. display. The present invention can be advantageously carried out by means of a computer program which comprises coding means for the realization of 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 which comprise a recorded message, said computer readable means comprising program coding means for carrying out one or more method steps , when this program is run on a computer. The vehicle can be equipped with a single processing unit that also controls the prime mover or it can be equipped with a first processing unit that controls the prime mover and a second processing unit that, specifically, monitors the position of all the levers and controls in the vehicle cabin and controls the operation of the on-board organs, such as the hydraulic valves of the hydraulic circuit, the displacement of the hydraulic pump driven by the prime mover to power the hydraulic circuit that allows the operation of the various actuators.

Implementing variations to the non-limiting example described are possible, without however departing from the scope of protection of the present invention, including all the equivalent realizations for a person skilled in the art, to the content of the claims.

From the above description, the person skilled in the art is able to realize the object of the invention without introducing further construction details.

Claims

1. Method for aiding the orientation adjusting of a tool(TO) with respect to a reference (H, Z) for a work or agricultural vehicle (WL), the vehicle including

. an arm (B) having a first end hinged to the vehicle and a second end hinged to the tool,

. a prime mover,

. a hydraulic pump adapted to be driven in rotation by the prime mover and to feed at least a first actuator (Al) adapted to adjust an angular position of the arm (B) with respect to the vehicle and . a second actuator (A2) adapted to adjust an angular position of the tool with respect to the reference, the method including

+ a first step (Step 1) of verifying at the same time that:

- (CK1) the speed of the prime mover is lower than a predetermined rotation speed threshold,

- (CK2) the vehicle speed is lower than a predetermined vehicle speed threshold,

- (CK3) an intensity of the control command of the second actuator (A2) given by means of a lever is lower than a predetermined intensity threshold, and only when all conditions (CK1, CK2, CK3) are verified 26

+ a second step (Step 2) to show, through a man/machine interface, an angular phase shift (, b) of the tool with respect to the reference (Z, H).

2. Method according to claim 1, wherein said man/machine interface includes a display arranged to indicate a positive or negative numerical value corresponding to the angular phase shift of the tool with respect to the reference or a set of lights associated to labels arranged to indicate said angular phase shift and/or wherein said reference coincides with a longitudinal axis (Z) of the vehicle or with a horizontal plane (H).

3. Method according to claim 1 or 2, wherein said man/machine interface includes an intermittent acoustic signal whose frequency is greater the lower the modulus of the angular phase displacement of the tool with respect to the reference and wherein said sound is continuous when said angular phase shift is zero.

4. Method according to claim 3, wherein said intermittent sound is enabled only when (CK4) said angular phase shift is less than a predetermined threshold or when a specific command is enabled by means of said man/machine interface.

5. Method according to any one of claims 1 - 4, wherein the reference can be selected to coincide with the longitudinal 27 axis (Z) of the vehicle or with a horizontal plane (H) by means of said man/machine interface.

6. Method according to any one of the preceding claims, wherein said first step further comprises (CK5) verifying that the arm is below a predetermined height.

7. Method according to any one of the preceding claims, further comprising a third step (Step 3) of selecting, by means of said man/machine interface, the type of tool (TO) connected to the arm (B), such as a shovel or a fork, and a consequent fourth step (Step 4) of modifying the calculation of the angular shift according to the type of tool selected.

8. Method according to claim 7, further comprising a preliminary calibration procedure (Step 5) comprising adding a new tool to a list of tools,

- adjustment of said first and/or second actuator until a configuration is identified wherein said tool results in a zero phase shift angle with respect to the reference,

9. Computer program comprising program coding means adapted to perform all steps (1 - 5) of any one of claims 1 to 8, 28 when said program is run on a computer.

10. Computer readable means comprising a recorded program, said computer readable means comprising program coding means adapted to carry out all steps (1 - 5) of any one of claims 1 to 8, when said program is run on a computer.

11. Work or agricultural vehicle comprising

. a prime mover,

. a hydraulic pump adapted to be driven in rotation by the prime mover and to feed at least a first actuator (Al) adapted to adjust an angular position of the arm with respect to the vehicle, and a second actuator (A2) adapted to adjust an angular position of a tool with respect to the arm,

- processing means configured to verify simultaneously that:

(CK1) the speed of the prime mover is lower than a predetermined rotation speed threshold,

(CK2) the vehicle speed is lower than a predetermined vehicle speed threshold,

(CK3) an intensity of the command given by means of a control lever is lower than a predetermined intensity 29 threshold, and only when all the conditions (CK1, CK2, CK3) are verified, the processing means are configured to show an angular phase shift (, b) of the tool with respect to the reference (Z, H) through a man/machine interface.