Mobile work machine and method for controlling safety function of mobile work machine

Abstract

The invention relates to a mobile work machine (2) having a front loading device (4), a brake system (22) and a central control device (60) by means of which a brake circuit can be controlled and a safety function of the work machine can be operated. In order to carry out a safety function and in order to avoid a collision with an obstacle located in front of the work machine, the following components are present and are connected to the central control device in a signalling manner: a front-field monitoring device (122) having at least one distance sensor (124, 124a, 124b) arranged at the vehicle front end of the work machine, the distance sensor (124, 124a, 124b) being connected to the central control device in a signalling manner; the distance sensor is used for determining the distance (A) between the working machine and the obstacle (18, 18 *); and a front-end loading monitoring device (128) having an adjustment positioning sensor (130) arranged at the front-end loading device. A method for controlling a safety function of such a mobile work machine provides that the distance of the work machine from an obstacle is determined by means of a distance sensor, and a warning signal is output and / or an emergency braking is carried out depending on the distance.

Description

Field of the Invention

[0001] The present invention relates to a mobile (i.e., self-propelled) work machine having: a front loading device with a liftable loading equipment; a hydraulic or pneumatic braking facility having at least one electronically controllable braking circuit; and a central control device by means of which the braking circuit can be at least indirectly controlled and the safety functions of the work machine can be run. The present invention also relates to a method for controlling the safety functions of such a work machine, by means of which a collision with an obstacle located in front of the work machine can be avoided. Background Art

[0002] Mobile work machines, such as tractors, wheel loaders, forklifts, and telescopic forklifts, usually have a front loading device with a liftable loading equipment, such as a loading shovel or loading forks, depending on the type of construction. When picking up goods, the lowered loading equipment is carefully driven forward at a low speed in the case of contact picking up towards, for example, a pile of bulk materials or a pallet stacked with items. When unloading the picked-up goods, first reverse away from the picking-up location with the raised loading equipment and drive forward towards the unloading location, such as the loading surface of a heavy vehicle or a trailer or the loading platform of a rack. It is also possible that an accidental collision occurs between the work machine, especially its loading equipment, and an obstacle such as a heavy vehicle, a trailer, or a rack due to the poor visibility for the driver when the loading equipment is raised. Of course, it is also possible that a person located in the unloading area is accidentally hit. Such collisions can cause damage to the work machine and devices and injuries to people and should therefore be avoided.

[0003] Driver assistance systems for motor vehicles mainly intended for road traffic and their control methods are already well known. In the driver assistance system, data inside and outside the vehicle regarding the vehicle's surrounding environment are at least partially sensed and evaluated. When the evaluation of these data results in a risk of collision with an obstacle located in front of the vehicle, emergency braking of the motor vehicle is initiated and executed.

[0004] Therefore, DE 10 2014 004 110 A1 describes a method for operating an autonomous driving safety system or a driver assistance system of a motor vehicle, which autonomous driving safety system or driver assistance system can act as an emergency braking system. When using the emergency braking function, it is set that when the evaluation of at least partially sensed data inside and outside the vehicle results in an impending collision with a vehicle traveling in front or an obstacle with a fixed relative orientation, emergency braking is initiated and executed.

[0005] A method for automatically performing emergency braking of a motor vehicle is known from DE 10 2017 100 980 A1, in which parameters inside and outside the vehicle are acquired and evaluated. The method is configured such that when a dangerous situation is recognized based on the evaluation of the parameters inside and outside the vehicle, emergency braking is performed. Summary of the Invention

[0006] Based on this background, the object of the present invention is to provide a mobile working machine of the type mentioned at the beginning, which has means for avoiding collisions with obstacles located in front of the working machine. In addition, a method for controlling the safety function of such a working machine should also be described, by means of which collisions with obstacles located in front of the working machine can be avoided.

[0007] The solutions to these tasks are defined in the independent claims. Advantageous designs and improvements are defined in the respectively assigned dependent claims.

[0008] Therefore, the present invention first relates to a working machine having: a front-end loading device having a liftable loading device; a hydraulic or pneumatic braking facility having at least one electronically controllable braking circuit; and a central control device by means of which the braking circuit can be controlled at least indirectly and the safety function of the working machine can be run.

[0009] To solve the tasks related to this device, it is provided that, in order to perform the safety function and thus to avoid collisions with obstacles located in front of the working machine, the following components also exist and are connected to the central control device in terms of signal technology:

[0010] - A front-field monitoring device having at least one distance sensor arranged at the vehicle front end of the working machine for acquiring the distance between the working machine and an obstacle located in front of the working machine, and

[0011] - A front-end loading monitoring device having an adjustment position sensor arranged at the front-end loading device for acquiring the current adjustment position of the loading device.

[0012] Therefore, the present invention is based on a mobile (i.e., self-propelled) working machine, such as a tractor, a wheel loader, a forklift or a telescopic forklift, which has a front-end loading device with a liftable loading device (such as a loading shovel or loading forks), and a hydraulic or pneumatic braking facility having at least one electronically controllable braking circuit. In addition, there is also a central control device by means of which the braking circuit can be controlled at least indirectly and the safety function of the working machine can be run.

[0013] Due to the electronically controllable brake circuit of the braking facility, a feasible solution for electronically triggering an emergency brake is provided as a safety function. With the distance sensor of the front field monitoring device, the distance to an obstacle located in front of the working machine can be determined, so that if the current distance to the obstacle reaches or falls below a critical distance, acoustic and optical warning signals are output and / or the emergency brake is activated and executed. With the adjustment position sensor of the front-end loading monitoring device, the current adjustment position of the loading device can be determined, and from this it can be confirmed whether the loading device is within or outside the detection range of the distance sensor. Depending on the confirmation result, it can then be decided whether to activate or deactivate the relevant safety function for avoiding collisions with obstacles located in front of the working machine.

[0014] Since the traveling speed of the mobile working machine is relatively low and the distances to other vehicles and relatively stationary obstacles in the working environment of the mobile working machine are relatively small, the distance sensor of the front field monitoring device is preferably configured as an ultrasonic sensor. The distance sensor is connected to the electronic control device via an electrical sensor line. However, other types of distance sensors are also feasible, for example as embodiments of infrared sensors, laser sensors or imaging sensors.

[0015] The adjustment position sensor of the front-end loading monitoring device can be configured as a rotation angle sensor, which is arranged at a suitable joint of the front-end loading device and is connected to the electronic control device via an electrical sensor line.

[0016] As an alternative or additionally as a redundancy, the adjustment position sensor of the front-end loading monitoring device can also be configured as a pressure sensor, which is coupled to a suitable adjustment cylinder of the front-end loading device and is connected to the electronic control device via an electrical sensor line.

[0017] When the traveling transmission of the working machine is configured as an electronically controllable CVT transmission, the emergency brake can be supported by continuously increasing the transmission ratio of the traveling transmission. A CVT transmission generally refers to a cone-disk belt transmission whose transmission ratio can be changed steplessly.

[0018] If the traveling transmission of the working machine is configured as an electronically controllable stepped transmission and can be switched to a neutral position that interrupts the power transmission between the drive motor and the drive axle, then the emergency brake of the working machine can also be supported by correspondingly controlling the traveling transmission by canceling the driving force of the drive motor.

[0019] When an electronically controllable disconnect clutch is arranged in the drive train of a work machine and the power transmission between the drive motor and the drive axle can be interrupted by disengaging the disconnect clutch, the emergency braking of the work machine can also be supported by correspondingly controlling the disconnect clutch.

[0020] As described at the beginning, the invention also relates to a method for controlling the safety functions of a mobile work machine, which has a front-end loading device with a liftable loading equipment; the mobile work machine has a hydraulic or pneumatic braking facility with at least one electronically controllable brake circuit; and the mobile work machine has a central control device by means of which the brake circuit can be at least indirectly controlled and the safety functions of the work machine can be run.

[0021] To solve the task associated with this method, it is provided that the distance between the work machine and an obstacle located in front of the work machine is ascertained by means of at least one distance sensor arranged at the front end of the vehicle of the work machine of the front-field monitoring device, and a warning signal is output and / or an emergency braking is carried out depending on the magnitude of the ascertained distance.

[0022] Therefore, this method for controlling the safety functions of a mobile work machine is used to avoid collisions with obstacles located in front of the work machine. The prerequisite is that the mobile work machine has a front-end loading device with a liftable loading equipment and a hydraulic or pneumatic braking facility with at least one electronically controllable brake circuit. By ascertaining in a sensing manner the distance between the work machine and an obstacle located in front of the work machine, a warning signal can be output when reaching or falling below a greater distance from the obstacle, and / or an emergency braking can be initiated and carried out when reaching or falling below a smaller distance from the obstacle.

[0023] To avoid the distance sensor being blocked and the resulting incorrect control of the safety function, according to an improvement of the method, it is provided that the current adjustment position of the loading equipment is ascertained by means of an adjustment position sensor arranged at the front-end loading device of the front-end loading monitoring device, and the safety function is enabled or disabled depending on whether the loading equipment is outside or inside the detection range of the distance sensor.

[0024] For this purpose, the adjustment range of the loading equipment is divided into an upper adjustment range and a lower adjustment range. In the upper adjustment range, the loading equipment is outside the detection range of the distance sensor, and in the lower adjustment range, the loading equipment is inside the detection range of the distance sensor. When the current adjustment position of the loading equipment is in the upper adjustment range, the safety function is enabled, and when the current adjustment position of the loading equipment is in the lower adjustment range, the safety function is disabled. Thus, the blocking of the distance sensor and the resulting incorrect control of the safety function are largely excluded.

[0025] Since the safety function is limited to monitoring the front field of the construction machinery, in a further design of the method, it can be provided that the current driving direction of the working machine is determined by means of at least one acceleration sensor and / or by means of at least one wheel speed sensor, and the safety function is enabled when the working machine is moving forward, while the safety function is deactivated when the working machine is moving backward or in a stationary state.

[0026] In order to warn the driver of the working machine of a possible collision with an obstacle and a possible triggering of an emergency brake, it can also be provided that when the detected distance reaches or falls below a predefined larger first distance boundary value, for example, an acoustic and / or optical warning signal is output in the driver's cab of the working machine.

[0027] When the detected distance reaches or falls below a predefined smaller second distance boundary value, the emergency brake is preferably triggered by means of an electronically controllable brake circuit that actuates the corresponding brake means.

[0028] Since the braking distance of the vehicle is proportional to the square of the driving speed, it is therefore preferable to provide a plurality of distance boundary values for different forward speeds, wherein the distance boundary values are proportional to the square of the forward speed.

[0029] As an alternative thereto, it is also possible to multiply the set distance boundary values by a speed-dependent correction factor K, which is proportional to the square of the forward driving speed.

[0030] According to a further improvement of the method, advantageously, the braking value signal output to the electronic brake control device for emergency braking is determined in a variable manner depending on the forward driving speed, wherein the braking value signal increases as the forward driving speed increases. It is not absolutely necessary for the increase in the output braking value signal to be quadratic, since at higher forward driving speeds, i.e., at a greater distance from the obstacle, the emergency brake is activated earlier.

[0031] In order to support the emergency braking of the working machine, in the case where a trailer vehicle is coupled to the working machine, when the emergency brake is triggered, the electronically controllable trailer control valve that actuates the working machine is actuated so that the trailer also decelerates.

[0032] Furthermore, the emergency braking of the work machine can also be supported in the following ways, that is, when the emergency braking is triggered, the electronically controllable drive motor that drives the work machine is made to operate in an inertial coasting mode, or when the emergency braking is triggered, the transmission ratio of the travel transmission of the work machine, which is configured as an electronically controllable continuously variable transmission (CVT), is continuously and steplessly increased, or when the emergency braking is triggered, the travel transmission of the work machine, which is configured as an electronically controllable stepped transmission, is switched to a neutral position that interrupts the power transmission between the drive motor and at least one drive axle, or when the emergency braking is triggered, the electronically controllable disengaging clutch arranged in the drive train of the work machine is disengaged to interrupt the power transmission between the drive motor and the drive axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be explained in detail below with reference to the embodiments shown in the drawings. Among them:

[0034] Figure 1 shows a mobile work machine with a front-end loading device in a first working position;

[0035] Figure 2 shows the work machine according to Figure 1 in a second working position; and

[0036] Figure 3 shows a schematic diagram of the braking facility of the mobile work machine. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Figure 1 and Figure 2 The mobile work machine 2 shown in

[0038] and Figure 3is schematically drawn therein, and its structure and mode of operation will be further explained below. In addition, the wheel loader 2 also has a front field monitoring device 122, which has at least one distance sensor 124 arranged at the front end of the vehicle of the working machine 2 for obtaining the distance to obstacles 18, 18* located in front of the working machine 2; and also has a front-end loading monitoring device 128, which has an adjustment positioning sensor 130 arranged at the front-end loading device 4 for obtaining the current adjustment positioning of the loading device 12 (here the loading shovel 12). The adjustment positioning sensor 130 can be configured as a rotation angle sensor, which is arranged at the joint 6 of the front-end loading device 4 and is connected to the central electronic control device 60 of the working machine 2 via an electrical sensor line 132. Alternatively, the adjustment positioning sensor 130 can also be configured as a pressure sensor, which is connected to the adjustment cylinder 14 of the front-end loading device 4 and is connected to the central control device 60 via an electrical sensor line 132.

[0039] For the safety function setting to avoid the working machine 2 from colliding with obstacles 18, 18* located in front of the working machine 2, it is to obtain the distance to the obstacles 18, 18* located in front of the working machine 2 by means of the distance sensor 124 of the front field monitoring device 122, and output a warning signal and / or trigger and execute an emergency brake depending on the obtained distance. In addition, it is set that the current adjustment positioning of the loading device 12 (here the loading shovel 12) is detected by means of the adjustment positioning sensor 130 of the front-end loading monitoring device 128, and the safety function is enabled or disabled depending on whether the loading device 12 is outside or within the detection range of the distance sensor 124.

[0040] For this purpose, the adjustment range B of the loading device 12 is divided into an upper adjustment range B o and a lower adjustment range B u , in the upper adjustment range, the loading device 12 is outside the detection range of the distance sensor 124, while in the lower adjustment range, the loading device 12 is within the detection range of the distance sensor 124. When the current adjustment positioning of the loading device 12 is within the upper adjustment range B o , the safety function is enabled, while when the current adjustment positioning of the loading device 12 is within the lower adjustment range B u , the safety function is disabled.

[0041] In Figure 1 , the working machine 2 is drawn in a first working position, in which the working machine 2 drives forward with the lowered loading shovel 12 to the bulk materials 16, such as sand, gravel, corn or grain, piled up in the front field of the working machine 2 for picking up goods. Since the lowered loading shovel 12 is within the lower adjustment range B uwithin and thus within the detection range of the distance sensor 124, where the safety function is deactivated.

[0042] In Figure 2 , the work machine 2 is depicted in a second working position, in which the work machine 2 is ready with the raised loading shovel 12 to unload the previously picked-up bulk material 16 onto the loading surface 20 of the trailer vehicle 18* parked in front of the work machine 2. The trailer vehicle 18* represents the obstacle 18 mentioned above. Since the raised loading shovel 12 is within the upper adjustment range B o within and thus outside the detection range of the distance sensor 124, where the safety function is activated. In order to avoid an undesired collision between the work machine 2 and the trailer vehicle 18* during further forward travel, the safety function, which is also only activated during forward travel, is set such that when the detected distance A between the work machine 2 and the trailer vehicle 18* reaches or falls below a predefined larger first distance boundary value A1, an acoustic and / or optical warning signal is output in the driver's cab of the work machine 2.

[0043] When the work machine 2 approaches the trailer vehicle 18* further, the safety function is set such that when the known distance A reaches or falls below a predefined smaller second distance boundary value A2 (A ≤ A2), an emergency brake is triggered and executed via the electronically controllable brake circuit 106 of the corresponding drive control brake facility 22. The two mentioned distance boundary values A1, A2 can be determined in a variable manner depending on the travel speed v F and can be determined to be larger as the travel speed v F increases, in particular proportional to the square of the travel speed v F (A1 ~ v F 2 , A2 ~ v F 2 ).

[0044] Likewise, the braking value signal output to the electronic brake control device 40 of the brake facility 22 for emergency braking can be determined in a variable manner depending on the forward travel speed v F such that the braking value signal increases as the forward travel speed v F increases. When the brake facility 22 (as shown in Figure 3 ) has an electronically controllable trailer control valve 88, then in the case of the trailer 18* being coupled to the work machine 2, the emergency braking can also be supported and thus the braking of the trailer 18* can be supported by correspondingly actuating the trailer control valve 88.

[0045] In Figure 3The known braking facility 22 of the mobile working machine 2 is shown in the schematic illustration, and the method with the features of the present invention can be used in this braking facility. The working machine 2 has a non-driven front axle 24 with two front wheels 26a, 26b arranged on both sides and a rear axle 28 configured as a drive axle with two rear wheels 30a, 30b arranged on both sides. Wheel speed sensors 32a, 32b, 36a, 36b are respectively arranged on the wheels 26a, 26b, 30a, 30b of the two axles 24, 26, and the wheel speed sensors are connected to the aforementioned electronic braking control device 40 via sensor lines 34a, 34b, 38a, 38b. With the braking control device 40, the driving direction and driving speed v of the working machine 2 can be determined based on the sensor signals of the wheel speed sensors 32a, 32b, 36a, 35b F .

[0046] The braking facility 22 has a hydraulic main braking facility 72 and a hydraulic secondary braking facility 106 as well as the aforementioned pneumatic trailer control valve 88. The hydraulic pressure medium source 42 includes an oil pump 46, and the oil pump can transport hydraulic oil from the hydraulic collection container 44 to the hydraulic pressure medium preparation device 50 via a relay valve 48. In the hydraulic pressure medium preparation device 50, the transported hydraulic oil is purified, cooled and guided into two reserve lines 52, 62. Hydraulic pressure sensors 54, 64 and hydraulic pressure memories 58, 68 are respectively connected to these two reserve lines 52, 62. The two pressure sensors 54, 64 are connected to the central electronic control device 60 of the working machine 2 via electrical sensor lines 56, 66. An operating element 70 configured as a driving direction lever is also connected to the control device 60, and the driving direction of the working vehicle 2, i.e., forward and reverse, can be selected via this operating element

[0047] The main braking facility 72 can be used as a service braking facility and as a steering braking facility, and currently has two braking circuits, which are respectively assigned to one vehicle side. The main braking facility 72 includes a first reserve line 52 with an assigned hydraulic pressure memory 58, two foot brake valves 74a, 74b that can be mechanically operated by the driver of the working machine 2 via the brake pedal respectively, an axle relay valve 76, and two wheel braking lines 78a, 78b. The two foot brake valves 74a, 74b are connected to the reserve line 52 on the input side and to the axle relay valve 76 on the output side. The axle relay valve 76 is also connected to the reserve line 52. The two wheel braking lines 78a, 78b lead from the axle relay valve 76 to the wheel brake cylinders 80a, 80b respectively. The two wheel brake cylinders 80a, 80b are configured as actively acting diaphragm brake cylinders or piston brake cylinders and are arranged at the wheel brakes of the rear wheels 30a, 30b

[0048] In the function as a service brake facility, the brake pedals of the foot brake valves 74a, 74b are mechanically coupled to each other, so that when one of the two brake pedals is depressed, the same braking pressure is synchronously applied to the two wheel brake cylinders 80a, 80b, and thereby the work vehicle 2 is decelerated in a track-stable manner. In the function as a steering brake facility, the brake pedals are mechanically separated, so that when one of the two brake pedals is depressed, the braking pressure is only applied to the assigned wheel brake cylinder 80a; 80b, and thereby supports the turning or reversing maneuver of the work vehicle 2 in the relevant direction.

[0049] The adjustment strokes of the associated valve pistons are detected by adjustment stroke sensors 82a, 82b arranged respectively on the two foot brake valves 74a, 74b and are transmitted via electrical sensor lines 84a, 84b to the central control device 60, where brake value signals can be formed based on the respective adjustment stroke signals. The central control device 60 is connected to the brake control device 40 via a data bus 86 (such as a CAN bus).

[0050] The trailer control valve 88 is connected on the input side via a third reserve line 92 to a compressed air source 90 and via a brake control line 94 to the axle relay valve 76 of the main brake facility 72. In addition, the trailer control valve 88 is connected to the brake control device 40 via an electrical control line 96 and is thus also electronically controllable. In normal operation, the pneumatic reserve pressure applied on the input side is guided through the trailer control valve 88 as required and reduced and is guided on the output side via a fourth reserve line 98 to the "reserve" coupling head (red) 100. In addition, depending on the braking pressure applied in the brake control line 94 and / or the control signal transmitted via the control line 96, a brake control pressure is adjusted in the trailer control valve 88, which is guided via a brake control line 102 to the "brake" coupling head (yellow) 104. When the trailer is coupled, its brake facility operating with compressed air is supplied with the reserve pressure applied on the "reserve" coupling head 100 and is controlled depending on the brake control pressure applied on the "brake" coupling head 104.

[0051] The secondary braking facility 106 is configured to be electronically controllable and at least serve as an auxiliary braking facility, enabling the work vehicle 2 to decelerate safely under the function of the auxiliary braking facility when the main braking facility 72 fails. The secondary braking facility 106 has only one braking circuit and includes a second reserve line 62 with an associated hydraulic pressure accumulator 68, a brake control valve 108, an axle brake line 110 branched into two wheel brake lines 112a, 112b, and two wheel brake cylinders 114a, 114b respectively connected to one of the wheel brake lines 112a, 112b. The two wheel brake cylinders 114a, 114b are configured as actively acting diaphragm brake cylinders or piston brake cylinders and are arranged on the wheel brakes of the front wheels 26a, 26b.

[0052] The brake control valve 108 is configured as a three-position three-way proportional solenoid valve having a pressure medium input end, a pressure medium output end, and a working interface, wherein the working interface can continuously be adjusted between the connection of the pressure medium output end and the pressure medium input end. The pressure medium input end is connected via the second reserve line 62 to the hydraulic pressure medium source 42, the pressure medium output end is connected to an unpressurized hydraulic collection container, and the working interface is connected via the axle brake line 110 to the wheel brake cylinders 114a, 114b. By correspondingly driving the brake control valve 108, the braking pressure acting in the axle brake line 110 and in the wheel brake cylinders 114a, 114b connected to the axle brake line 110 can be adjusted steplessly between a minimum pressure corresponding to the ambient pressure and a maximum pressure corresponding to the reserve pressure applied in the reserve line 62.

[0053] The electromagnet of the brake control valve 108 can be directly driven by the brake control device 40 via the electrical control line 116 of a two-core wire. The working interface of the brake control valve 108 is connected to the pressure medium output end in the de-energized state and is connected to the pressure medium input end in an unthrottled manner in the fully energized state. To detect and monitor the braking pressure introduced into the axle brake line 110 via the brake control valve 108, an electro-hydraulic pressure sensor 118 is connected to the axle brake line 110, and the electro-hydraulic pressure sensor is connected to the brake control device 40 via an electrical sensor line 120. Thus, the secondary braking facility 106 can be controlled in a purely electronic manner. Therefore, the braking pressure in the axle brake line 110 and in the wheel brake cylinders 114a, 114b connected to the axle brake line 110 can be adjusted independently of the main braking facility 72 and depending on the braking value signal, and the braking value signal can be determined in the brake control device 40 according to the sensor signals of the adjustment stroke sensors 82a, 82b or in other ways.

[0054] To perform the safety function, in Figure 3Also shown are two distance sensors 124a, 124b of the front field monitoring device 122, which are preferably configured as ultrasonic sensors, and an adjustment positioning sensor 130 of the front-end loading monitoring device 128. The two distance sensors 124a, 124b are arranged laterally offset at the front end of the vehicle of the working machine 2 and are connected to the central control device 60 via electrical sensor lines 126a, 126b. As Figure 1 and Figure 2 shown, the adjustment positioning sensor 130 is arranged on the front-end loading device 4 and is connected to the central control device 60 via an electrical sensor line 132.

[0055] List of reference numerals (part of the description)

[0056] 2 Mobile working machine, wheel loader

[0057] 4 Front-end loading device

[0058] 6 Frame

[0059] 8 Joint

[0060] 10 Support arm

[0061] 12 Loading equipment, loading shovel

[0062] 14 Adjusting cylinder

[0063] 16 Bulk material

[0064] 18 Obstacle

[0065] 18* Trailer vehicle, obstacle

[0066] 20 Loading surface

[0067] 22 Braking facility

[0068] 24 Front axle

[0069] 26a First front wheel

[0070] 26b Second front wheel

[0071] 28 Rear axle, drive axle

[0072] 30a First rear wheel

[0073] 30b Second rear wheel

[0074] 32a First wheel speed sensor

[0075] 32b Second wheel speed sensor

[0076] 34a First sensor line

[0077] 34b Second sensor line

[0078] 36a Third wheel speed sensor

[0079] 36b Fourth wheel speed sensor

[0080] 38a Third sensor line

[0081] 38b Fourth sensor line

[0082] 40 Brake control device

[0083] 42 Hydraulic pressure medium source

[0084] 44 Collection container

[0085] 46 Oil pump

[0086] 48 Relay valve

[0087] 50 Pressure medium preparation device

[0088] 52 First reserve line

[0089] 54 First pressure sensor

[0090] 56 Fifth sensor line

[0091] 58 First pressure memory

[0092] 60 Central control device

[0093] 62 Second reserve line

[0094] 64 Second pressure sensor

[0095] 66 Sixth sensor line

[0096] 68 Second pressure memory

[0097] 70 Operating element, travel direction lever

[0098] 72 Main braking facility

[0099] 74a First foot brake valve

[0100] 74b Second foot brake valve

[0101] 76 Axle relay valve

[0102] 78a First wheel brake line

[0103] 78b Second wheel brake line

[0104] 80a First wheel brake cylinder

[0105] 80b Second wheel brake cylinder

[0106] 82a First adjustment stroke sensor

[0107] 82b Second adjustment stroke sensor

[0108] 84a Seventh sensor line

[0109] 84b Eighth sensor line

[0110] 86 Data bus, CAN bus

[0111] 88 Trailer control valve

[0112] 90 Compressed air source

[0113] 92 Third reserve line

[0114] 94 First brake control line

[0115] 96 First control line

[0116] 98 Fourth reserve line

[0117] 100 "Reserve" coupling (red)

[0118] 102 Second brake control line

[0119] 104 "Brake" coupling (yellow)

[0120] 106 Secondary brake facility, brake circuit

[0121] 108 Brake control valve

[0122] 110 Axle brake line

[0123] 112a Third wheel brake line

[0124] 112b Fourth wheel brake line

[0125] 114a Third wheel brake cylinder

[0126] 114b Fourth wheel brake cylinder

[0127] 116 Second control line

[0128] 118 Third pressure sensor

[0129] 120 Ninth sensor line

[0130] 122 Front field monitoring device

[0131] 124 First distance sensor, ultrasonic sensor

[0132] 124a Second distance sensor, ultrasonic sensor

[0133] 124b Third distance sensor, ultrasonic sensor

[0134] 126a Tenth sensor line

[0135] 126b Eleventh sensor line

[0136] 128 Front-end loading monitoring device

[0137] 130 Adjustment positioning sensor, rotation angle sensor or pressure sensor

[0138] 132 Twelfth sensor line

[0139] A Detected distance

[0140] A1 First distance boundary value

[0141] A2 Second distance boundary value

[0142] B Adjustment range, swing range

[0143] B o Upper adjustment range, upper swing range

[0144] B u Lower adjustment range, lower swing range

[0145] K Correction coefficient

[0146] v F Travel speed, forward travel speed

Claims

1. A mobile working machine (2), the mobile working machine having: a front-end loading device (4), the front-end loading device having a load-carrying device (12) that can be raised and lowered; a hydraulic or pneumatic braking facility (22), the braking facility having at least one electronically controllable braking circuit (106); and a central control device (60), by means of which the braking circuit (106) can be controlled at least indirectly and the safety functions of the working machine (2) can be run, characterized in that For performing a safety function and thus for avoiding a collision with obstacles (18, 18*) located in front of the work machine (2), there are also the following components present and connected to the central control device (60) in terms of signal technology: - A front field monitoring device (122) having at least one distance sensor (124, 124a, 124b) arranged at the vehicle front end of the work machine (2), the distance sensor being used to determine the distance (A) between the work machine (2) and the obstacles (18, 18*) located in front of the work machine (2), and - A front-end loading monitoring device (128) having an adjustment position sensor (130) arranged at the front-end loading device (4), the adjustment position sensor being used to determine the current adjustment position of the loading device (12).

2. The mobile working machine according to claim 1, characterized in that, At least one distance sensor (124, 124a, 124b) of the front field monitoring device (122) is configured as an ultrasonic sensor and is connected to the electronic control device (60) via electrical sensor lines (126a, 126b).

3. The mobile working machine according to claim 1 or 2, characterized in that, The adjustment position sensor (130) of the front-end loading monitoring device (128) is configured as a rotation angle sensor, is arranged at a suitable joint (8) of the front-end loading device (4), and is connected to the electronic control device (60) via an electrical sensor line (132).

4. The mobile working machine according to any one of claims 1 to 3, characterized in that, The adjustment position sensor (130) of the front-end loading monitoring device (128) is configured as a pressure sensor, is arranged at an adjustment cylinder (14) of the front-end loading device (4), and is connected to the electronic control device (60) via an electrical sensor line (132).

5. The mobile working machine according to any one of claims 1 to 4, characterized in that, The travel transmission of the work machine (2) is configured as an electronically controllable CVT transmission, and the transmission ratio of the CVT transmission can be changed steplessly.

6. The mobile working machine according to any one of claims 1 to 4, characterized in that, The travel transmission of the work machine (2) is configured as an electronically controllable stepped transmission, and the travel transmission can be switched to a neutral position that interrupts the power transmission between the drive motor of the work machine (2) and at least one drive axle (28) of the work machine (2).

7. The mobile working machine according to any one of claims 1 to 6, characterized in that, An electronically controllable disengaging clutch is arranged in the drive train of the work machine (2), and by disengaging the disengaging clutch, the power transmission between the drive motor and at least one drive axle (28) can be interrupted.

8. A method for controlling a safety function of a mobile work machine (2), the mobile work machine having a front-end loading device (4), the front-end loading device having a liftable loading device (12), the mobile work machine having a hydraulic or pneumatic braking facility (22), the braking facility having at least one electronically controllable brake circuit (106), and the mobile work machine having a central control device (60) by means of which the brake circuit (106) can be controlled at least indirectly and the safety function of the work machine (2) can be run, characterized in that The distance (A) between the work machine (2) and the obstacles (18, 18*) located in front of the work machine (2) is determined by at least one distance sensor (124, 124a, 124b) of the front field monitoring device (122) arranged at the vehicle front end of the work machine (2), and a warning signal is output and / or an emergency brake is executed depending on the determined distance (A).

9. The method according to claim 8, characterized in that The current adjustment position of the loading device (12) is determined by means of an adjustment position sensor (130) arranged on the front-end loading device (4) of the front-end loading monitoring device (128), and the safety function is enabled or disabled depending on whether the loading device (12) is outside or within the detection range of the distance sensor (130).

10. The method according to claim 9, wherein The adjustment range (B) of the loading device (12) is divided into an upper adjustment range (B o ), and a lower adjustment range (B u ). In the upper adjustment range, the loading device (12) is outside the detection range of the distance sensor (130). In the lower adjustment range, the loading device (12) is within the detection range of the distance sensor (130). And when the current adjustment position of the loading device (12) is within the upper adjustment range (B o ), the safety function is enabled. While when the current adjustment position of the loading device (12) is within the lower adjustment range (B u ), the safety function is disabled.

11. The method according to any one of claims 8 to 10, characterized in that, The current travel direction of the work machine (2) is determined by means of at least one acceleration sensor and / or at least one wheel speed sensor (32a, 32b, 36a, 35b), and the safety function is enabled when the work machine (2) is traveling forward, and disabled when the work machine is traveling backward or at a standstill.

12. The method according to any one of claims 8 to 11, characterized in that, When the detected distance (A) reaches or falls below a predefined larger first distance limit value (A1), an acoustic and / or optical warning signal is output.

13. The method according to any one of claims 8 to 12, characterized in that, When the detected distance (A) reaches or falls below a predefined smaller second distance limit value (A2), an emergency brake is triggered by actuating the electronically controllable brake circuit (106) of the brake facility (22).

14. The method according to claims 12 and 13, characterized in that, Set multiple distance boundary values (A1, A2) for different forward driving speeds (v F ), where the distance boundary values (A1, A2) are proportional to the square of the forward driving speed (v F ).

15. The method according to claims 12 and 13, characterized in that, Multiply the set distance boundary values (A1, A2) by a speed-dependent correction factor (K), where the correction factor (K) is proportional to the square of the forward driving speed (v F ). (K ~ v F ²).

16. The method according to any one of claims 13 to 15, characterized in that, depend on the forward driving speed (v) in a variable manner F ), a braking value signal output to an electronic braking control device (40) for emergency braking is determined, wherein the braking value signal increases as the forward driving speed (v F ) increases.

17. The method according to any one of claims 8 to 16, characterized in that In the case where a trailer vehicle (23) is coupled to the work machine (2), when an emergency brake is triggered, the electronically controllable trailer control valve (88) of the work machine (2) is actuated so that the trailer vehicle decelerates.

18. The method according to any one of claims 8 to 17, characterized in that When an emergency brake is triggered, the electronically controllable drive motor of the work machine (2) is actuated so that the drive motor operates in a coasting mode.

19. The method according to any one of claims 8 to 17, characterized in that, When an emergency brake is triggered, the transmission ratio of the travel transmission of the work machine (2), which is configured as an electronically controllable continuously variable transmission (CVT), is continuously increased steplessly.

20. The method according to any one of claims 8 to 17, characterized in that When an emergency brake is triggered, the travel transmission of the work machine (2), which is configured as an electronically controllable stepped transmission, is switched to a neutral position in which the power transmission between the drive motor and at least one drive axle (28) is interrupted.

21. The method according to any one of claims 8 to 17, characterized in that When an emergency brake is triggered, the electronically controllable disconnect clutch arranged in the drive train of the work machine (2) is disengaged, thereby interrupting the power transmission between the drive motor and the drive axle (28).

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