Operating device

Abstract

Operating device for controlling at least one state variable of an agricultural or industrial vehicle (28), comprising at least one operating lever (12), an actuating device (22), at least one sensor (16), and a control unit (14), wherein the operating lever (12) can be actuated by one hand of an operator, wherein a state variable of the vehicle (28) can be adjusted with the operating lever (12), wherein the at least one operating lever (12) can be actuated with a force by the actuating device (22), wherein a quantity representing a state variable of the vehicle (28) can be detected with the at least one sensor (16) and transmitted to the control unit (14), wherein a state variable of the current operating state of the vehicle (28) can be determined with the control unit (14), and wherein the actuating device (22) can be controlled by the control unit (14) depending on the currently existing operating state of the vehicle (28).that the at least one control lever (12) can be acted upon with a modified, predefinable force in order to make an unsafe operating state of the commercial vehicle (28) or an unsafe operating state of at least one working function (30) perceptible to the operator, wherein the control lever (12) is designed in the form of a joystick with which a working function (30) or a state variable of the commercial vehicle (28) or a working function or a state variable of a work device adapted to the commercial vehicle (28) can be adjusted, wherein a loader and / or a loader tool can be controlled with the joystick, characterized in that at least one lower and / or one upper tilt angle value of the loader tool can be predefinable, at which a predefinable maximum force acts on the joystick.

Description

[0001] The present invention relates to an operating device for controlling at least one state variable of an agricultural or industrial vehicle. An operating lever of the device can be actuated by one hand. The operating lever allows for the adjustment of a state variable of the vehicle. Furthermore, the present invention relates to a method for controlling at least one state variable of an agricultural or industrial vehicle.

[0002] Such control devices have long been known in the art. They can be used, for example, to adjust the speed, steering, a work function, or the transmission setting of a commercial vehicle. A joystick, in particular, is used as a control lever to operate a loader attachment. Commercial vehicles in this context include, in particular, agricultural vehicles such as tractors, harvesters, combine harvesters, forage harvesters, and self-propelled sprayers, but also industrial vehicles such as construction vehicles, bulldozers, leveling machines, backhoe loaders, loaders, dump trucks, cranes, and telescopic handlers.

[0003] Force feedback, also known as force recirculation, is a well-known technique in simulator technology, where it typically serves to realistically represent the forces acting on control elements that occur during the operation of a real machine and must be applied or overcome by the operator. This involves an actuator or control device that can apply a force to at least one control lever. Thus, the control lever, which in this case only generates an electrical signal indicating its operating state, can be actuated with at least one corresponding force by the actuator, so that the control lever exhibits operating characteristics typical for that type of control lever.

[0004] In many vehicles, the controls are typically mechanically connected to the machine part they control, for example, the steering wheel via the steering shaft to the steering linkage. If such a mechanical connection is eliminated due to electronic control of the respective component, the corresponding feedback to the operator regarding the states of the machine part and the simulated machine / vehicle is lost. In such a case, technology known from simulator engineering is used by applying forces to the control lever via an actuator, which is controlled by a suitable control unit, in such a way that a typical operating characteristic for the control lever can be generated. This simulates the most realistic possible operation of the respective function controlled by the control lever for the operator.

[0005] Further assistance in operating a commercial vehicle is provided to the operator visually or, if necessary, audibly through warning indicators. These primarily consist of warning lights that indicate a critical condition of the vehicle, such as an excessively high temperature of the engine oil or coolant exceeding a predefined upper limit.

[0006] Furthermore, DE 10 2005 000 633 A1 discloses a forklift truck in which vibrations can be generated at the joystick of the forklift truck's hydraulic system by means of a feedback device. The haptic feedback generated at the joystick by the feedback device allows for safe and direct feedback of vehicle states and / or vehicle information during operation of the forklift truck, for example, a lifting height set by an operator at the joystick that reduces the vehicle's stability.

[0007] The present invention is based on the objective of specifying and further developing an operating device of the type mentioned at the outset, by which an operator of a commercial vehicle is given further support in operating the commercial vehicle, and by which an operator is also made aware of a critical or non-optimal operating condition of the commercial vehicle in an improved manner.

[0008] The problem is solved according to the invention by the teaching of claim 1. Further advantageous embodiments and developments of the invention are set forth in the dependent claims.

[0009] According to the invention, an operating device of the type mentioned above comprises at least one operating lever, an actuating device, at least one sensor, and a control unit. The operating lever can be operated by one hand. A state variable of the commercial vehicle can be adjusted using the operating lever. The actuating device or actuator can apply a force to the at least one operating lever. A quantity representing a state variable of the commercial vehicle can be detected by the at least one sensor and transmitted to the control unit. The control unit can determine a state variable of the current operating state of the commercial vehicle.Depending on the current operating state of the commercial vehicle, the control unit can actuate the actuator in such a way that at least one control lever can be subjected to a modified, predefinable force, thereby making an unsafe operating state of the commercial vehicle or an unsafe operating state of at least one working function perceptible to the operator. The control lever is designed as a joystick, with which a working function or a state variable of the commercial vehicle, or a working function or a state variable of a work implement adapted to the commercial vehicle, can be set. A loader and / or a loader attachment can be controlled with the joystick. At least one lower and / or one upper tilt angle value of the loader attachment can be predefinable, at which a predefinable maximum force acts on the joystick.The changed force could, for example, be a constant or a variable force.

[0010] According to the invention, it has first been recognized that the operation of a commercial vehicle can be simplified and optimized, in particular, if the operator is not only shown an unsafe or suboptimal operating condition by visual display instruments. Commercial vehicles typically have a tachometer to display the speed of the internal combustion engine. If the internal combustion engine is continuously operated at an increased speed that exceeds the maximum speed intended for continuous operation, a conventional commercial vehicle provides no further indication, apart from increased engine noise, which may not always be audible in a relatively well-soundproofed cabin. This can lead to engine damage and therefore to a prolonged downtime of the commercial vehicle and consequently high consequential costs.According to the invention, it is therefore provided that, in addition to an acoustic and / or visual warning device, the operator is also made aware of such an operating condition of the commercial vehicle in a tactile manner. This is particularly advantageous when the operator must react immediately in some way due to the situation, for example, to prevent an overload of a component of the commercial vehicle or an accident involving the commercial vehicle.

[0011] The control unit can use the sensor signal to calculate the direction or position in which the operating lever should be moved to achieve the desired purpose. Generally, the trend of the effects caused by changing a state variable is known. The position and / or direction of movement of the operating lever that would result in a safe operating state is determined. The actuator is then controlled according to the result of a comparison between the calculated, favorable direction and / or position of movement and / or position and the actual direction and / or position of movement of the operating lever.

[0012] The control unit preferably receives information about the position of the control lever – detected by a control lever position sensor – which can be taken into account when calculating the desired or undesired direction of movement or position of the control lever. However, in some applications, taking the position of the control lever into account is not necessary. It is also conceivable that the control unit derives information about the position of the control lever and / or its direction of movement from the sensor signal or its changes.

[0013] The actuating device can be operated in two fundamentally different ways. On the one hand, it can generate an adjustment resistance or an amplitude and / or frequency of the mechanical excitation of the operating lever, which is proportional to the difference between the current position of the operating lever and a calculated, optimal position of the operating lever, or which depends continuously and preferably monotonically on this difference in some other way. Thus, if the operating lever is in a particularly unfavorable position, it is very difficult to move it into an even less favorable position, or it vibrates quite strongly and / or rapidly. In the opposite direction, however, it can be moved easily, or the vibrations subside or disappear. On the other hand, it is possible that the actuating device only becomes effective when the aforementioned difference exceeds a certain threshold value.The actuator can produce a stepwise increasing adjustment resistance, or the amplitude and / or frequency of the mechanical excitation can be changed in steps. In this embodiment, the adjustment resistance or the amplitude and / or frequency of the mechanical excitation of the input element thus increases in at least one step. An advantage lies in the simpler technical implementation, since in the simplest case the actuator only needs to be switchable on and off.

[0014] Depending on the current operating state of the commercial vehicle, the control unit could also control the actuator in such a way that at least one operating lever can be actuated with a changed, predefinable force, in order to make the operator aware of a non-optimal operating state of the commercial vehicle or a non-optimal operating state of at least one working function.

[0015] According to a preferred embodiment of the present invention, the operating characteristics of the control lever are modifiable by applying a predetermined, variable force to the control lever. For example, the control lever could be subjected to a force such that it can only be operated by the operator with increased effort. In other words, in this embodiment, the force applied to the control lever by the actuating device during normal operation of the commercial vehicle is increased by a constant value (offset) if the vehicle is not operating in an optimal or safe condition.

[0016] The control lever could, for example, be designed as a hand throttle lever, allowing adjustment of the engine speed of the commercial vehicle's internal combustion engine or the vehicle's speed. Alternatively, the control lever could be designed as a hydraulic control lever. In this case, the hydraulic control lever would be used to set or operate a hydraulic function. One such function could be the height adjustment of a tractor's three-point implement linkage. This is an example of a commercial vehicle function where the two lifting cylinders of the three-point implement linkage are controlled according to the lever's operation.Another example could be the control of corresponding hydraulic cylinders on a loader, a loader vehicle, or an optional loader attachment adaptable to a tractor, where the loader's hydraulic cylinders are controlled depending on the operation of the control lever. Furthermore, it is conceivable to design the control lever in the form of a gearshift lever. Such a gearshift lever would be used to select a gear position.

[0017] The force acting on the joystick could depend on the lifting height of the loader or the loader attachment. It can be advantageous for the force acting on the joystick to increase with increasing height of the loader or loader attachment. This is particularly relevant for safety reasons, especially when dealing with a ballasted vehicle and a raised loader attachment. This is especially important for telescopic handlers, as in addition to the lifting height and tilt angle of the loader attachment, the length of the loader arm or boom can also be changed, for example, by extending or retracting it. This increases the risk of the telescopic handler becoming unbalanced. The same applies to cranes.

[0018] Preferably, at least one height value – preferably a lower and / or an upper one – of the loader / loading attachment can be preset, at which a preset maximum force is applied to the joystick. This signals to the operator that the loader attachment is approaching or has reached its maximum or minimum height. The at least one height value could be storable and / or modifiable by the operator, allowing the operator to configure the control device depending on the specific task at hand.

[0019] At least one tilt angle value could also be saved and / or changed by an operator.

[0020] It is also conceivable to design the operating lever as a push-button switch or toggle switch. Such a push-button switch or toggle switch could also be used to control a function or state of the commercial vehicle, or a function or state of an implement adapted to the commercial vehicle. In the case of a push-button switch, the function controlled by the switch could be activated or deactivated (e.g., mechanical front-wheel drive on / off, power take-off on / off). In the case of a toggle switch, the function controlled by the switch could be toggled between at least two different states (transmission reverser forward / reverse).

[0021] The at least one sensor detects a quantity that represents a state variable of the commercial vehicle.A state variable of the commercial vehicle could be, for example, the speed, the acceleration, the direction of travel, the currently set steering angle, the deviation from a predetermined direction of travel, the spatial position of the commercial vehicle, the yaw motion or yaw moment, the determination of an obstacle, the rotational speed of an engine or transmission shaft, the rotational speed of at least one wheel, the torque transmitted by a shaft, the torque delivered by a drive unit, the power or load of a drive unit, the energy consumption or fuel consumption of a consumer, the slip of the commercial vehicle over the ground, an axle load, the pressure or volume flow or volume flow change of a hydraulic fluid, the extension travel of a cylinder, the driving condition, the tractive force of the commercial vehicle and / or the force acting on the commercial vehicle of a trailer and / or an implement.A force acting on the commercial vehicle can be, in particular, a tensile force, a lateral force, and / or a support force. Accordingly, at least one sensor could be provided with which a quantity can be detected that enables the determination of the speed, acceleration, direction of travel, the currently set steering angle, the deviation from a predetermined direction of travel, the spatial position of the commercial vehicle (relative to a reference system), and / or the identification of an obstacle.The sensor could also detect a quantity that enables the determination of the rotational speed of an engine or transmission shaft, the rotational speed of at least one wheel, the torque transmitted by a shaft, the torque delivered by a drive unit, the power or load of a drive unit, the energy consumption or fuel consumption of a consumer, the slippage of the commercial vehicle over the ground, an axle load, the pressure or volume flow or change in volume flow of a hydraulic fluid, the extension stroke of a cylinder, the tractive force acting on the commercial vehicle by a trailer and / or an implement, the driving condition and / or the tractive force of the commercial vehicle. The sensor will typically be designed to detect or record such a quantity.An (electrical) signal, dependent on the detected quantity, is then generated and transmitted to the control unit. Depending on the vehicle's current operating state, the control unit can then generate a signal or signal sequence to control at least one actuator accordingly.

[0022] Specifically, the positioning device has at least one actuator. The actuator could be electrically, pneumatically, or hydraulically actuated. Thus, depending on its actuation, the actuator can apply a variable force to the operating lever. The positioning device could also have a further actuator, which, for example, is in the form of a spring and applies a constant force or force characteristic to the operating lever.

[0023] An optimal operating condition of a commercial vehicle exists, in particular, when the vehicle exhibits minimized fuel consumption and / or when the driving speed or efficiency of the vehicle, or individual components thereof, is optimally adapted to the current operating mode. In other words, individual components or the entire vehicle are adjusted so that their efficiency is optimized or adapted to the current operating mode. A current operating mode could, for example, be plowing with a tractor to which a plow is attached. Another current operating condition could involve sowing seeds if a seed drill is attached to the tractor.Optimal operating conditions are also sought when the material processed or handled by the commercial vehicle, and possibly with an implement adapted to the vehicle, exhibits optimal throughput or turnover. An example of this could be a tractor with a round baler adapted to it. In optimal operating conditions, the round baler is operated in such a way that the hay picked up by the baler is processed at maximum conveying speed (maximum throughput) without causing a blockage.

[0024] A safe operating condition of the commercial vehicle exists, in particular, when the engine load, the vehicle's inclination relative to the horizontal, the yaw moment, the vehicle's ballast (including any attached implement), the prevailing torque load in the drivetrain, the rotational speed of components in the drivetrain, and / or the vehicle's speed (including when cornering) do not exceed a corresponding predefined limit. Other safety-relevant parameters include, for example, the aforementioned engine oil temperature, the temperature of the coolant in the vehicle's internal combustion engine, and the pressure of a hydraulic braking system. Accordingly, a safe operating condition of the commercial vehicle exists when the corresponding predefined limits are neither exceeded nor fallen below.A safe operating condition of the commercial vehicle exists even if there is no obstacle in its driving area or operating area. In other words, an unsafe operating condition exists if the relevant predefined limit values ​​are exceeded or not reached, and / or if there is an obstacle in the driving area or operating area of ​​the commercial vehicle.

[0025] The operating device according to the invention is particularly helpful for the safe operation of the commercial vehicle with regard to state variables that cannot be directly observed by the operator. This could be especially relevant for trailers attached to the commercial vehicle (e.g., a sprayer with an extended spray boom), which, for example, can roll and / or yaw due to uneven ground and thereby bring the vehicle and trailer combination into a dangerous state. In such a case, the control lever (which sets the vehicle speed) could be subjected to a force such that the operator is prompted to deflect the control lever to reduce the speed of the combination.

[0026] The actuator could be controlled by the control unit in such a way that the actuator applies a substantially constant force to the operating lever. Such a procedure could particularly apply to the state of the operating lever when it is in the neutral position and not being operated by a user.

[0027] Alternatively or additionally, the actuator could apply a predefined force profile to the control lever. This predefined force profile could exhibit a continuous analytical function depending on the actuation path or deflection of the control lever, or the state variable being controlled. This analytical function could change over time, thereby taking into account changes in the operating state of the commercial vehicle.

[0028] Particularly when the commercial vehicle approaches an unsafe operating condition, or when the operator misuses a work function or vehicle function, the actuating device could be designed to apply a time-varying force to the control lever, whether it is in the neutral position or in any other position. This is especially helpful in operating conditions where the current state variable or critical variable cannot be directly perceived by the operator. This could, for example, apply to the torque transmitted from a tractor via the power take-off (PTO) shaft to an implement attached to the tractor, which exceeds a predefined limit.Accordingly, the operating lever could be subjected to a force that varies over time by the actuating device, causing the operating lever to perform a kind of vibrating movement and thereby alerting the operator to a critical operating condition in a tactile manner.

[0029] In general, and according to a particularly preferred embodiment, the operating lever is subjected to a predefinable, modified force if an operating condition deviating from the optimal operating condition exists. Optimal operating conditions are specifically enumerated in the cases of claim 14, although this enumeration is not exhaustive and accordingly a multitude of further optimal operating conditions may exist. Also in general, and according to a particularly preferred embodiment, the operating lever is subjected to a predefinable, modified force if an operating condition deviating from the safe operating condition exists. Safe operating conditions are specifically enumerated in the cases of claim 15, although this enumeration is not exhaustive and accordingly a multitude of further safe operating conditions may exist.

[0030] The following section discusses relatively specific situations in which the operating lever is subjected to a predetermined, modified force.

[0031] This is the case, among other things, when the current operating state or a current state variable of the commercial vehicle or a working function of the commercial vehicle exceeds or falls below a predefined limit. This could, for example, involve a hydraulic fluid pressure exceeding a maximum value, which is used to control a hydraulic cylinder of a loader, where the loader might be adapted to a tractor. Such a situation could, for example, indicate an overload when lifting the loader bucket.

[0032] The operating lever could then be subjected to a predetermined, modified force if the rotational speed of a shaft and / or the rotational speed of a shaft of a working device deviates from a predetermined rotational speed.

[0033] The control lever could also be subjected to a predetermined, variable force if the vehicle's speed deviates from a predefined speed. If the vehicle is performing a work function that requires it to move at a substantially constant speed (e.g., sowing seeds), the operator could be alerted to this by changing the force applied to the control lever.

[0034] Preferably, the operating lever can be subjected to a predefinable, variable force, which depends on the condition of the road surface or the substrate. This could be used to reduce or avoid the "bonanza effect." For this purpose, depending on the current movement of the commercial vehicle, which is detected by a corresponding motion and / or acceleration sensor, the force is applied to the operating lever in such a way that a self-reinforcing oscillation of the commercial vehicle or its working function is largely prevented when the operator's hand moves during operation of the operating lever due to the movement of the commercial vehicle.

[0035] In a preferred embodiment, the operating lever in its neutral position can be subjected to a predetermined high force by the actuating device, at least in a specific operating state of the commercial vehicle. The operator can deflect the operating lever from its neutral position once with a correspondingly high force to transition the commercial vehicle and / or a working function of the commercial vehicle from a locked state to an operating state. This creates a so-called force lock for the function controlled by the operating lever. The operator must initially exert a relatively high force to activate the function. Once the function is activated, it is advantageous not to subject the operating lever to the predetermined high force again, or to only do so if the operating lever has not been actuated for an extended period.Similarly, an acknowledgment of the vehicle's start-up or a shift acknowledgment for a transmission shift could be implemented; that is, the control actually desired by the operator is acknowledged by overcoming the high force.

[0036] Furthermore, it could be provided that the control lever can be subjected to a predefined force to make the operator aware that a change to a state variable of the commercial vehicle or a work function, commanded by the control lever, has now been completed. Particularly when the control lever operates a transmission shift, but the control lever is not mechanically connected to the transmission shift point because, for example, it is controlled by an electromagnetic actuator, this can give the operator realistic feedback after the shifting operation has been carried out.When the transmission has been engaged in the newly commanded shift state via the control lever, a predetermined force impulse (of low magnitude) can be exerted on the control lever, which is comparable to the force impulse exerted on a control lever mechanically connected to the transmission shift point by the shifting process of the transmission shift point.

[0037] Similarly, the control lever could be subjected to a predetermined force to make the operator aware that a specific state of a work implement adapted to the commercial vehicle exists. This could be the case, for example, if a work implement is engaged and only reaches its operating speed after a time delay. When this occurs, the control lever could also be subjected to a force impulse.

[0038] Preferably, the amount of force that can be applied to the operating lever is individually adjustable by the operator. This allows, for example, each operator to set and, if necessary, save a customized operating characteristic for the lever. This enables a personalized setting of the operating lever characteristics and can thus prevent operating errors and / or allow for individual ergonomic operation.

[0039] In a preferred embodiment, the operating lever can be programmed with a predefinable operating characteristic such that an operator can easily find a desired setting, a deflection position, or a deflection range of the operating lever – which may be adjustable by the operator. Such a desired setting could be the working depth of the lifting mechanism of a three-point implement attachment if the lifting mechanism height is adjusted using the operating lever. If the working depth of the lifting mechanism is being adjusted, a "locking" action of the operating lever could be provided, which can be achieved by applying a corresponding force to the operating lever via the actuating device. Similarly, an adjustable "stop" of the operating lever could be provided, which may be predefinable or adjustable by the operator, enabling the user to find a specific picking and / or unloading height for a front loader.This could also be helpful in finding a specific tilt angle of the bucket or an upper limit of the excavation height (due to a low ceiling height in buildings or a low clearance height of gates).

[0040] According to a preferred embodiment of the present invention, the control lever can be subjected to a force such that an operator avoids an unfavorable setting range of an operating state of a working function or state variable of the commercial vehicle – e.g., the natural frequency of the tires at certain rotational speeds. The engine speed-dependent natural frequency of the engine mount and / or the natural frequency of the vehicle body could also exhibit an unfavorable setting range and could therefore signal the operator to avoid this setting in a comparable manner by applying a corresponding force to the control lever.

[0041] In a further embodiment, an operating lever can be subjected to a predetermined force, which is essentially dependent on the state of another operating element of the commercial vehicle. This allows, for example, the simulation of mutual interlocking between several operating elements, such as a parking lock that can be activated in a tractor with one operating lever and an adjustment lever for the transmission of that tractor, which can be controlled with another operating lever. This advantageously eliminates the need for the previously required mechanical coupling of the two operating levers.

[0042] It could be provided that the force exerted by the actuator on the control lever can be overridden and / or deactivated by the operator. Overriding the force exerted on the control lever by the operator should generally be possible, because the operator should not only feel that they have control over the operation of the vehicle. Rather, for safety reasons, the vehicle should also be operable by the operator even if the control lever is subjected to an incorrect force. This could be the case if a sensor detects a value incorrectly or the detected value is misinterpreted, even if this occurs with only a slight probability.

[0043] As already mentioned, in addition to applying a predetermined force to the control lever, a visual and / or audible signal could be generated. This is particularly useful if a safe operating state of the commercial vehicle and / or a work function is abandoned. In this case, for example, a light source integrated into the control lever could be activated, possibly with increasing brightness as the level of danger increases. Additionally or alternatively, an audible signal in the form of a warning tone (possibly with increasing volume) could be generated and communicated to the operator. Thus, it could be provided that an operator can be warned of a safety risk tactilely and visually at the control lever, as well as audibly via a loudspeaker in the cab, preferably concerning a function controlled by the lever.

[0044] The utility vehicle, which has an operating device according to the invention, could be a self-propelled work machine or a tractor used in agriculture, construction, or forestry. In particular, the utility vehicle could be in the form of a tractor, a harvester, a combine harvester, a forage harvester, a construction machine, and / or a forestry machine. Accordingly, the function controlled by the operating lever of the operating device could be a characteristic working function of the respective utility vehicle.

[0045] There are now various ways to advantageously elaborate and further develop the teaching of the present invention. For this purpose, reference should be made, on the one hand, to the claims subordinate to claim 1 and, on the other hand, to the following explanation of preferred embodiments of the invention with reference to the drawing. In conjunction with the explanation of the preferred embodiments of the invention with reference to the drawing, generally preferred embodiments and further developments of the teaching are also explained. The drawing shows each of these in a schematic representation. Fig. 1 an embodiment of an operating device according to the invention, Fig. 2 an embodiment of an agricultural vehicle with an operating device according to the invention, Fig. 3a an agricultural vehicle with a loader in which the loader bucket is not to be raised above a predetermined height, Fig. 3b a diagram of the force exerted on the control lever as a function of the height of the loader bucket, Fig. 4a an agricultural vehicle with a loader, in which the loader bucket is to be used in a predetermined height range, Fig. 4b a diagram of the force exerted on the control lever as a function of the height of the loader bucket, Fig. 5a an agricultural vehicle with a loader in which the tilting angle of the loader bucket is to remain within a predefinable angular range and Fig. 5b a diagram of the force exerted on the control lever as a function of the tilting angle of the loader bucket.

[0046] In the figures, identical or similar components are marked with the same reference symbols.

[0047] Fig. Figure 1 shows an embodiment of an operating device 10 according to the invention. Fig. The operating device 10 shown in Figure 1 comprises an operating lever 12, a control unit 14, and a sensor 16. The operating lever 12 is designed in the form of a joystick and can be deflected in two directions 18 and 20 that are essentially perpendicular to each other, as well as combinations thereof. The Fig. The control device shown in 10 controls a front loader of a vehicle in Fig. The two shown are agricultural utility vehicles designed in the form of a tractor. The front loader is made of Fig. 2 is hydraulically controlled. Therefore, the control lever 12 is ultimately designed as a hydraulic control lever. Accordingly, when the control lever 12 is deflected in direction 20, the loader bucket is raised or lowered. When the control lever is actuated in direction 18, the loader bucket is tilted at an angle relative to the horizontal. Thus, the control lever 12 sets or controls a state variable of the commercial vehicle or the front loader adapted to it. The operating device 10 further comprises an actuating device 22, which has two actuators 24 and 26. The two actuators 24 and 26 are electrically controlled components and operate according to the moving-coil principle. One actuator, 24, applies a push or pull force to the control lever 12, which is essentially directed in direction 20.The other actuator 26 applies a push or pull force to the operating lever, which is essentially directed in direction 18. Actuators 24 and 26 are equipped with sensors (not shown) that can determine the current position of the operating lever 12 and transmit this information to the control unit 14. Sensor 16 detects an angular signal of the angle between the horizontal and the boom of the front loader (in ). Fig. (1 not shown). With appropriate calibration, the current height of the loader bucket can be determined from this angle signal. The sensor 16 detects this angle signal and generates an electrical signal, which is transmitted to the control unit 14. The control unit 14 uses the angle signal to determine the current height of the loader bucket.

[0048] According to the invention, the control unit 14, depending on the current state of the front loader, controls the positioning device 22 and thus the actuators 24, 26 in such a way that the operating lever 12 can be actuated with a modified, predefinable force. This allows a Fig. 1. The operator (not shown) may be made aware of a less than optimal or unsafe operating condition of the commercial vehicle or tractor in conjunction with the front loader. Accordingly, the operating characteristics of the control lever 12 can be changed by applying a predefinable variable force to the control lever 12 via the actuating device 22.

[0049] Fig. Figure 2 shows an agricultural vehicle, namely a tractor 28, which has the operating device 10 according to the invention. Fig. 1. The tractor 28 is fitted with a front loader 30, which has a boom 32 and a loader bucket 34. The boom 32 of the front loader 30 can be raised or lowered by means of the double-acting hydraulic cylinder 36.

[0050] Several sensors are arranged on the tractor 28 and the front loader 30, although not all sensors are required to carry out the present invention. Sensor 38 can determine the extension stroke of the piston rod of the hydraulic cylinder 36. Sensor 40 measures the change in the volume flow of the hydraulic fluid supplied to and from the hydraulic cylinder 36. Sensor 42 measures the pressure of the hydraulic fluid in the piston chamber of the hydraulic cylinder 36. Sensor 44 detects the vehicle speed over the ground. Sensor 46 detects the rotational speed of the left front wheel 48. Sensors are also provided for the other three wheels, but these are located in a different configuration. Fig. 2 are not shown. Sensor 50 detects the set steering angle of the front wheel 48. Sensor 52 detects the acceleration of the tractor 28. Sensor 54 detects the force exerted by a device adapted to the tractor 28. Fig. 2. Implement not shown transmits power to the tractor 28. The torque transmitted to the rear drive can be detected with the sensor 56. Furthermore, a GPS receiver 58 is provided, with which GPS position signals can be received, from which the control unit 14 can determine the current position of the tractor 28. All sensors are connected to the control unit 14 via electrical connections. The actuator 22 is also connected to the... Fig. 2 actuators not shown are connected to the control unit 14. Although in Fig. 2 not shown, further sensors (such as those listed in claims 6 and 7) may be provided with which further quantities can be detected and from which a corresponding state variable of the commercial vehicle or a working function or from which a state variable of a working device adapted to the commercial vehicle can be derived or determined.

[0051] With the in the Fig. 3a, Fig. 4a and Fig. 5a indicated representations and the associated diagrams of the Fig. 3b, Fig. 4b and Fig. Section 5b shows only some embodiments of an operating device according to the invention, illustrating the force exerted on the control lever 12 as a function of the respective setting. A multitude of further embodiments are conceivable in which an operating device according to the invention could be used to control at least one state variable of an agricultural or industrial vehicle. Such embodiments are listed in particular in claims 13 to 29.

[0052] Fig. Figure 3a shows a tractor 28 with a front loader 30. The front loader 30 comprises a boom 32 and a boom tool, which is designed in the form of a loader bucket 34. The boom 32 is in a raised position. The maximum distance from the loader bucket 34 to the ground 60 specified for a particular application is indicated by the double arrow h. This distance (the height) can be determined using the [reference to be added]. Fig. 3a sensor 38 not shown for determining the extension path of the hydraulic cylinder 36 (see Fig. 2) and with the tilt angle sensor 62 to determine the tilt angle of the loader bucket 34. Fig. Figure 3b shows a schematic diagram in which the force exerted on the control lever 12 is plotted as a function of the current height of the loader bucket 34.

[0053] The deflection of the control lever 12 typically causes the corresponding front loader function to be switched on or off (in the sense of binary logic). For example, deflecting the control lever 12 forward raises the boom. It could be intended that, depending on a larger deflection angle of the control lever 12, the boom 32 is raised faster than with a smaller deflection angle. Accordingly, the control device could take this fact into account and exert a greater force on the control lever 12 if the control lever 12 is deflected through a larger angle.

[0054] The diagram shows the Fig. Figure 3b shows that the force curve exerted by the actuator 24 on the control lever 12 increases with increasing height of the loader bucket 34. The force curve exhibits an analytical function that is continuously and monotonically increasing in the range between a height of 0 and h. As the height of the loader bucket 34 approaches the value h, the actuator 24 exerts a greater force opposing the deflection of the control lever 12 than is the case when the loader bucket 34 is at a lower height. This signals to the operator of the control lever 12 that the loader bucket 34 is approaching its maximum height h for the current application. If the boom 32 and thus the loader bucket 34 were to be deflected further beyond the height h, which is quite conceivable given the design of the front loader 30, the control lever 12 would be subjected to an essentially constant force, as shown for values ​​greater than h in the diagram. Fig. Figure 3b shows that the operator can change the value of the height h depending on their specific application and save it accordingly.

[0055] In the embodiment according to Fig. 4a is the tractor 28 with the front loader 30 from the Fig. 2 and Fig. Figure 3a shows the boom 32 in an upper position, marked O. The boom 32 can be in a lower position, marked U, as indicated by the dashed line. In this embodiment, these two positions, O and U, represent the appropriate lifting and unloading heights for specific front loader operations.

[0056] Fig. Figure 4b shows a schematic diagram in which the force exerted on the control lever 12 is plotted as a function of the current height of the loader bucket 34. The force curve shown in this diagram indicates that the force exerted on the control lever 12 by the actuator 24 is continuous in a range between U and O and increases monotonically with increasing height of the loader bucket 34. The force exerted on the control lever 12 is less in this range than in a range below U or above O. This gives the operator the impression that when deflecting the control lever 12 within a height range of the loader bucket 34 between the predetermined values ​​O or U, the lever is being deflected against an end stop. The operator perceives a greater restoring force on the control lever 12 as the height of the boom 32 approaches the value O. The diagram from Fig. Figure 4b also shows that if the loader bucket 34 is located outside the range U to O, a greater restoring force is exerted on the control lever 12. Accordingly, it is possible for an operator to override this active force feedback measure and thus always retain control of the vehicle or implement, but this could lead to an unsafe operating state. In this embodiment as well, an operator can specify and save different values ​​for the two positions U and O in the system (for example, via a keyboard input not shown in the figures or by means of a corresponding menu using a display unit).

[0057] Fig. 5a also shows the tractor 28 from Fig. 4a with the front loader 30. In Fig. Figure 5a indicates that the loader bucket 34 can be tilted by a tilt angle range A specified by the operator for a specific application. Accordingly, the operating lever 12 is subjected to a force which is shown in the diagram of the Fig. 5b is shown. It is comparable to the diagram from Fig. 4b is shown in the diagram according to Fig. 5b The force applied to the control lever 12 when the loader bucket 34 is within the tilt angle range A is less than when it is outside this range. Within the tilt angle range A, the control lever 12 is subjected to an increasing force as the tilt angle of the loader bucket 34 approaches the lower tilt angle A1 or the upper tilt angle A2. This alerts the operator that the loader bucket 34 is approaching the lower or upper tilt angle A1 or A2. This also assists inexperienced operators in particular when operating the front loader 30. Furthermore, it is also possible to adjust the tilt angle of the loader bucket 34 beyond the lower or upper tilt angles A1 and A2.In this case, the operator must exert at least a correspondingly high force on the operating lever 12 if the tilt angle of the loader bucket 34 is outside the tilt angle range A.

[0058] The in the Fig. The embodiments shown in Figures 3a to 5a relate solely to the control of a joystick-style operating lever 12, which controls a front loader 30. Similarly, another function of the utility vehicle or tractor 28 could be controlled, for example, the three-point linkage, the transmission control, or the hand throttle setting. The same applies to a work implement possibly adapted to the utility vehicle, such as a mower or a round baler.

[0059] Finally, it should be emphasized that the exemplary embodiments discussed above serve only to describe the claimed teaching, but do not limit it to these exemplary embodiments.

Claims

[1] Operating device for controlling at least one state variable of an agricultural or industrial vehicle (28), comprising at least one operating lever (12), an actuating device (22), at least one sensor (16) and a control unit (14), wherein the operating lever (12) can be actuated by one hand of an operator, wherein a state variable of the vehicle (28) can be adjusted with the operating lever (12), wherein the at least one operating lever (12) can be actuated with a force by the actuating device (22), wherein a quantity representing a state variable of the vehicle (28) can be detected with the at least one sensor (16) and transmitted to the control unit (14), wherein a state variable of the current operating state of the vehicle (28) can be determined with the control unit (14), wherein the actuating device (22) can be controlled with the control unit (14) depending on the currently existing operating state of the vehicle (28),that the at least one control lever (12) can be acted upon with a modified, predefinable force in order to make an unsafe operating state of the commercial vehicle (28) or an unsafe operating state of at least one working function (30) perceptible to the operator, wherein the control lever (12) is designed in the form of a joystick with which a working function (30) or a state variable of the commercial vehicle (28) or a working function or a state variable of a work device adapted to the commercial vehicle (28) can be adjusted, wherein a loader and / or a loader tool can be controlled with the joystick, . characterized by , that at least one lower and / or one upper tilt angle value of the loader tool can be specified, at which a specified maximum force acts on the joystick. [2] Operating device according to claim 1, wherein the at least one tilt angle value can be stored and / or changed by an operator. [3] Control device according to claim 1 or 2, wherein the control device (14) can be used to control the actuating device (22) depending on the current operating state of the commercial vehicle (28) in such a way that the at least one control lever (12) can be actuated with a changed predefinable force in order to make the operator aware of a non-optimal operating state of the commercial vehicle (28) or of a non-optimal operating state of at least one working function (30). [4] Operating device according to one of claims 1 to 3, wherein the operating characteristic of the operating lever (12) can be changed by applying a predetermined altered force to the operating lever (12). [5] Operating device according to any one of claims 1 to 4, - wherein the control lever (12) is designed in the form of a hand throttle lever with which the engine speed or the speed of the commercial vehicle (28) can be adjusted and / or - wherein the operating lever (12) is designed in the form of a hydraulic control lever with which a hydraulic function or working function (30) can be adjusted and / or - wherein the operating lever (12) is designed in the form of a gearshift lever, with which a shift state of a transmission can be set. [6] Control device according to one of claims 1 to 5, wherein the force acting on the joystick depends on the lifting height of the loader or the loader tool and wherein preferably the force acting on the joystick increases with increasing height of the loader / loader tool. [7] Operating device according to one of claims 1 to 6, wherein at least one - preferably a lower and / or an upper - height value of the loader / loading tool can be preset, at which a preset maximum force acts on the joystick, and wherein preferably the at least one height value can be stored and / or changed by an operator. [8] Operating device according to one of claims 1 to 7, wherein the operating lever (12) is designed in the form of a push-button switch or changeover switch with which a working function or a state variable of the commercial vehicle (28) or a working function or a state variable of a work device adapted to the commercial vehicle (28) can be activated, deactivated and / or switched. [9] Operating device according to one of claims 1 to 8, wherein the sensor (16) can detect a quantity which enables the determination - the speed, - the acceleration, - the direction of travel, - of the currently set steering angle, - deviation from a predetermined direction of travel, - the spatial position of the commercial vehicle (28), - the yaw movement or yaw moment and / or - enables the determination of an obstacle. [10] Operating device according to one of claims 1 to 9, wherein the sensor (16) can detect a quantity which enables the determination - the rotational speed of a motor or transmission shaft, - the rotational speed of at least one wheel (48), - the torque transmitted by a shaft, - the torque delivered by a drive unit, - the performance or utilization of a drive unit, - the energy consumption or fuel consumption of a consumer, - the slippage of the commercial vehicle (28) over the ground, - an axle load, - the pressure or volume flow or volume flow rate change of a hydraulic fluid, - of the extension path of a cylinder (36), - the force acting on the commercial vehicle (28) of a trailer and / or an implement, in particular a tractive force, a lateral force and / or a support force, - the driving condition and / or - the tractive power of the commercial vehicle (28) enables. [11] Operating device according to one of claims 1 to 10, wherein the actuating device (22) has an actuator (24, 26) which can be actuated electrically, pneumatically or hydraulically. [12] Operating device according to one of claims 1 to 11, wherein an optimal operating state exists when - the commercial vehicle (28) has minimized fuel consumption and / or - if the driving speed or efficiency of the commercial vehicle (28) is optimally adapted to its current operating mode and / or - if the goods processed / handled with the commercial vehicle (28) and, if applicable, with a work device adapted to the commercial vehicle have an optimal throughput / turnover. [13] Operating device according to one of claims 1 to 12, wherein a safe operating state of the commercial vehicle (28) exists when - the engine load, - the inclination of the commercial vehicle (28) relative to the horizontal, - the ballasting of the commercial vehicle (28) with a work device possibly adapted to it, - the prevailing torque load in the drivetrain or the rotational speed of rotating components in the drivetrain and / or - the speed or yaw moment of the commercial vehicle (28) does not exceed a corresponding predeterminable limit. [14] Control device according to one of claims 1 to 13, wherein a safe operating condition of the commercial vehicle (28) exists when there is no obstacle in the driving area or area of ​​operation of the commercial vehicle (28). [15] Operating device according to one of claims 1 to 14, wherein the actuating device (22) applies a substantially constant force to the operating lever (12). [16] Control device according to one of claims 1 to 15, wherein the actuating device (22) applies a predetermined force profile to the control lever (12), wherein the force profile has a continuous analytical - possibly time-varying - function depending on the actuation path of the control lever (12) or the state variable to be controlled. [17] Control device according to one of claims 1 to 16, wherein the actuating device (22) applies a time-varying force to the control lever (12) which is in the neutral position or in any position, in particular in the event of misuse of the commercial vehicle (28) and / or a working function. [18] Operating device according to one of claims 1 to 17, wherein the operating lever (12) is acted upon with a predefinable, modified force if an operating condition deviating from the optimal operating condition - in particular according to claim 14 - exists. [19] Operating device according to one of claims 1 to 18, wherein the operating lever (12) is acted upon with a predefinable, modified force if an operating condition deviating from the safe operating condition - in particular according to claim 15 - exists. [20] Operating device according to one of claims 1 to 19, wherein the operating lever (12) is acted upon with a predefinable, modified force if the currently existing operating state or a currently existing state variable of the commercial vehicle (28) or a working function of the commercial vehicle exceeds or falls below a predefinite limit value. [21] Operating device according to one of claims 1 to 20, wherein the operating lever (12) is acted upon with a predefinable, modified force if the rotational speed of a shaft and / or a shaft of a working device deviates from a predefinite rotational speed. [22] Control device according to one of claims 1 to 21, wherein the control lever (12) is subjected to a predetermined, modified force if the speed of the commercial vehicle (28) deviates from a predetermined speed. [23] Operating device according to one of claims 1 to 22, wherein the operating lever (12) can be acted upon with a predefinable, variable force which depends on the nature of the roadway or the subsoil (60). [24] Operating device according to one of claims 1 to 23, wherein the operating lever (12) in its neutral position can be actuated by the actuating device with a predefinable high force and wherein the operating lever (12) can be deflected once from its neutral position by the operator with a correspondingly high force in order to transfer the commercial vehicle (28) and / or a working function (30) of the commercial vehicle (28) from a secured state to an operating state. [25] Control device according to one of claims 1 to 24, wherein the control lever (12) can be acted upon with a predefinable force to make the operator aware that a change of a state variable of the commercial vehicle (28) or of a working function (30) commanded by the control lever (12) has now been stopped. [26] Operating device according to one of claims 1 to 25, wherein the operating lever (12) can be acted upon with a predefinable force to make the operator aware that a certain state of a work device (30) adapted to the commercial vehicle (28) exists. [27] Operating device according to one of claims 1 to 26, wherein the level of force with which the operating lever (12) can be acted upon is individually adjustable by the operator, whereby each operator can set an individually adapted operating characteristic of the operating lever (12). [28] Operating device according to one of claims 1 to 27, wherein a predefinable operating characteristic can be imprinted on the operating lever (12) in such a way that an operator can find a desired setting, a deflection position or a deflection range of the operating lever (12). [29] Control device according to one of claims 1 to 28, wherein the control lever (12) can be acted upon with a force such that an operator avoids an unfavorable setting range of an operating state of a working function (30) or state variable of the commercial vehicle (28). [30] Control device according to one of claims 1 to 29, wherein an operating lever (12) can be acted upon with a predefinable force which is essentially dependent on the state of another control element of the commercial vehicle (28). [31] Operating device according to one of claims 1 to 30, wherein the force exerted by the actuating device (22) on the operating lever (12) can be overridden and / or switched off by the operator. [32] Operating device according to one of claims 1 to 31, wherein in addition to applying a predetermined force to the operating lever (12) a visual and / or acoustic signal can be generated. [33] Control device according to one of claims 1 to 32, wherein the commercial vehicle (28) is designed in the form of a self-propelled work machine or a tractor in the agricultural, construction or forestry sector, in particular in the form of a tractor, a combine harvester, a forage harvester, a construction machine and / or a forestry machine. [34] Agricultural or industrial utility vehicle, in particular tractor, which has an operating device (10) according to any one of claims 1 to 33.

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