WO2018178004A1

WO2018178004A1 - Method for operating an autonomous underground vehicle

Info

Publication number: WO2018178004A1
Application number: PCT/EP2018/057630
Authority: WO
Inventors: Dirk Brandenstein; Bernd WÜLLER; Christoph Funke; Thomas Deimel
Original assignee: Ghh Fahrzeuge Gmbh
Priority date: 2017-03-28
Filing date: 2018-03-26
Publication date: 2018-10-04
Also published as: DE102017106629A1

Abstract

The invention relates to a method for operating an autonomous underground vehicle (1), said underground vehicle (1) comprising: a lifting device (2) with at least one tool (3); a driving assembly (4) for moving the underground vehicle (1); a drive assembly (5) for driving the lifting device (2) and the driving assembly (4), said drive assembly (5) having a fluid transmission (6) and a diesel engine (7); and a control assembly (8) for actuating the drive assembly (5). The method is characterised in that the underground vehicle (1) comprises an input assembly (9) for a vehicle user (10) to specify both a driving speed of the underground vehicle (1) and a task to be carried out by the lifting device (2), and that the control assembly (8) controls the diesel engine (7) on the basis of a driving speed and task specified in each case by the vehicle user (10) by means of the input assembly (9). The invention also relates to a corresponding autonomous underground vehicle (1).

Description

Method for operating a self-propelled underground vehicle

The invention relates to a method for operating a self-propelled sub-vehicle with the features of the preamble of claim 1 and a self-propelled underground vehicle having the features of the preamble of claim 15.

From the state of the art, a large number of self-propelled underground vehicles are known, which are used in mining and tunneling for different types of work. Such self-propelled underground vehicles may, for example, be loaders, underground dump trucks, concrete mixers, mining vehicles, drilling rigs, tethering machines, tunneling machines, etc. The self-propelled underground vehicles in question here have a diesel engine in particular as an aggregate.

This diesel engine provides the power for both the movement of the downhole vehicle and the working of the hoist of the downhole vehicle with the implement or implements, the number and type of which depends on the particular type of downhole vehicle. A flow gearbox serves to translate the rotary motion emitted by the diesel engine into the movement of the downhole vehicle and the working activity of the hoist. In the known from the prior art - for example from DE 32 21 762 AI - known self-propelled underground vehicles, however, is a separate control element for substantially immediate adjustment of the engine power of the diesel engine - corresponding to an accelerator pedal in a car - on the one hand and a control element for actuating the On the other hand. The result is that to provide sufficient power for the operation of the hoist vehicle users must first increase the engine power of the diesel engine, which leads to a significant increase in the speed of the diesel engine for the first moment without significant load and only then actuates the hoist, through the resulting load, the speed of the diesel engine is depressed again until the required torque achieved. If the hoist operated too early in relation to the increase in engine power, there is a risk of "stalling" of the diesel engine.

A disadvantage of this approach of the prior art is that these frequent fluctuations in the speed of the diesel engine cause the diesel engine is regularly operated at an operating point, which has a worse than the desired efficiency. Firstly, this leads to unnecessarily high fuel consumption and to the generation of additional waste heat, the cooling of which in turn may require additional energy. Second, the variations in the speed of the diesel engine also increase the wear of the diesel engine. In the case of a diesel engine, regular fluctuations in the load of the diesel engine-that is, the torque delivered by the diesel engine-are considerably less serious for wear than these fluctuations in engine speed.

Based on this prior art, therefore, the object of the invention is to further develop and improve the known from the prior art self-propelled underground vehicle and the known method for operating the self-propelled underground vehicle that the operation both in terms of fuel consumption and in terms of wear becomes more economical.

Relative to a method for operating a self-propelled underground vehicle having the features of the preamble of claim 1, this object is solved by the features of the characterizing part of claim 1. Relative to a self-propelled underground vehicle having the features of the preamble of claim 15, this object is solved by the features of the characterizing part of claim 15. Essential for the invention is the realization that instead of an immediate adjustment of the engine power by the vehicle user, such as by pressing a pedal, rather a desired driving speed of the underground vehicle and a desired work activity of the hoist can be specified by the vehicle user and then based on the engine power can be set automatically. On the one hand, this would make it easier for the user of the vehicle to operate, since he would no longer be self-employed Diesel engine must regulate and on the other hand allow to avoid the fluctuations in the speed of the diesel engine or at least to reduce, especially since the regularly used in an underground vehicle flow gearbox is well suited for operation of the diesel engine at a substantially constant speed thanks to its stepless. It is also not clear when an immediate adjustment of engine performance by the vehicle user could be useful or necessary.

The proposed method is for operating a self-propelled underground day vehicle, wherein the downhole vehicle comprises a hoist with at least one implement, a driving arrangement for moving the underground vehicle and a drive arrangement for driving the hoist and the drive assembly, wherein the drive arrangement comprises a flow gear and a diesel engine. Next, according to the proposed method, the self-propelled underground vehicle on a control arrangement for driving the drive assembly - in particular so for driving the flow gear and the diesel engine - on.

The proposed method is characterized in that the sub-vehicle has an input arrangement for predetermining by a vehicle user both a travel speed of the underground vehicle and a working activity of the hoist to be executed. This driving speed is the speed with which the underground vehicle is to move or move. This input device can have arbitrary and possibly completely separate input devices for presetting the vehicle speed on the one hand and for specifying the work activity of the hoist to be executed on the other hand. The work to be performed may in particular be a working movement of an implement of the hoist.

The proposed method is further characterized in that the control arrangement regulates the diesel engine based on a respective predetermined by the vehicle user through the input device driving speed and work activity. In this way, the vehicle user is deprived of the possibility of directly setting the speed of the diesel engine and thereby opening up the possibility of having the diesel engine even with different combinations of ner predetermined driving speed and a given work activity with lower fluctuations in the speed to operate.

In principle, this control of the diesel engine can be configured as desired. A preferred embodiment is characterized in that the control arrangement determines a target speed of the diesel engine and controls the diesel engine to this target speed. Likewise, it is preferred that the control arrangement regulates the diesel engine by the variable supply of fuel and in particular regulates the diesel engine to the setpoint speed. Accordingly, then forms the amount of fuel supplied to the manipulated variable for the control. Further, it is preferred that the control arrangement sets a ratio of the flow gear so that at the target speed, the driving assembly moves the underground vehicle at the predetermined driving speed. It may be that, until reaching the predetermined driving speed, the ratio of the flow gear is adjusted so that the driving assembly temporarily moves the underground vehicle with a correspondingly lower or greater driving speed than the predetermined driving speed. There may in principle be circumstances under which a certain predetermined driving speed can not be achieved, such as in the presence of too high a gradient on the route.

In principle, the self-propelled underground vehicle may be any self-propelled underground vehicle. So it can either be a rail-guided or a rail-independent underground vehicle. As already stated, it can be, in particular, a loader loader, an underground dump truck, a concrete mixer, a conspirator vehicle, a drilling rig, a tethering device or a tunneling machine.

A further preferred embodiment is characterized in that the work activity predetermined by the vehicle user through the input arrangement comprises a predetermined lifting speed of the work activity. In other words, not only the work activity per se - such as a specific movement or operation of the implement - is given, but also the speed at which this work is to be performed. Regularly, the inherent work activity will require more power when running at higher speed. Here it can be further that the Lifting speed defines an execution time for completion of the specified work activity. In that regard, conversely, the execution time defines the stroke speed. According to a preferred embodiment, it is provided that the control arrangement determines a required operating power based on the predetermined driving speed and based on the predetermined operating activity that the control arrangement determines an operating point of the diesel engine based on the determined operating power, which operating point by a rotational speed and a load characteristic of the diesel engine is defined and at which operating point of the diesel engine provides at least the required operating power and that the control arrangement adjusts the diesel engine to the specific operating point. The required operating power is thus at least as high as the combined power required for moving the underground vehicle at the predetermined driving speed, in particular for accelerating the underground vehicle to the predetermined driving speed, and which is required for the work to be carried out. The load characteristic of the diesel engine is a characteristic known per se, which at a respective setting of the supply of fuel to the diesel engine, which is associated with the characteristic curve, above the rotational speed of the diesel engine removes the torque delivered by the diesel engine. The output at the respective operating point of the diesel engine is proportional to the product of speed and torque. Preferably, the particular required operating power is also based on the predetermined lifting speed. The relationship between the lifting speed and power has already been mentioned above.

A preferred embodiment is characterized in that the downhole vehicle has a hydraulic Lenkvor- direction driven by the drive arrangement for directing the Untertagefahrzeus and driven by the drive assembly cooling device for cooling the flow gear. Hydraulic transmissions generate comparatively much heat loss through friction, whereby active cooling is expedient. The cooling device can also be used for cooling other apparatus and devices. Preferably, the flow gearing is adapted to variably transfer the power provided by the diesel engine to the drive assembly, the hoist and possibly to the steering device and the cooling device. This allows the fluid transmission to preferentially transmit the power provided by the diesel engine to the steering device so that the steering device can always be sufficiently powered by the fluid transmission regardless of the given driving speed and work activity.

It may be that the hoist has only one implement. Likewise, it may be that the hoist comprises a plurality of implements, for which the input arrangement by the vehicle user specifies a respective work to be performed. It is therefore possible to specify different work activities for each different work equipment. Then, the control arrangement may preferably determine the required operating performance also based on the respective given work activities of the plurality of work tools.

Furthermore, it may be that the control arrangement also determines the required operating power based on a respective power for operating the steering device and for operating the cooling device. These require for their operation also a - not negligible - performance and can therefore be considered advantageous in the required operating performance.

A further preferred embodiment is characterized in that in a data memory of the underground vehicle, a set of load characteristics, which are preferably each characterized by a load characteristic associated adjustment of the supply of fuel to the diesel engine, are deposited for the diesel engine and that the operating points along the deposited Load curves each fuel consumption is assigned. The fuel consumption can be specified in particular per unit of time. Alternatively or additionally, it may be that the operating points along the stored load characteristics in each case an efficiency is assigned. In this way, different operating points can be compared in terms of their efficiency. It may also be that the control arrangement for determining the operating point of the diesel engine from the amount of the stored load characteristics that Load characteristic at which the operating point has the lowest fuel consumption - in particular per unit time - at the specific operating power. Alternatively, the control arrangement may select the load characteristic in which the operating point has the highest efficiency at the particular operating power. Since there are regularly several possible operating points on different load characteristics to provide a required operating performance, in this way simply the most economical operating point can be selected. According to a preferred embodiment, it is provided that the flow gearbox is a hydrostatic gearbox, which hydrostatic gearbox variably, preferably steplessly, converts a power output by the diesel engine into a volumetric flow of a hydraulic fluid of the hydrostatic gearbox. In particular, therefore, the size of the volume flow is variable.

A preferred embodiment is characterized in that the control arrangement determines a required minimum speed of the diesel engine based on the predetermined work activity. For certain work activities of certain tools of the hoist, it may be that a certain volume flow for performing this work is required, for which volume flow in turn a certain speed of the diesel engine - just the above minimum speed - is required. This is due to the fact that the volume flow can not be achieved by the conditions of the flow gear, when the output power from the diesel engine is indeed high enough, but the speed is too low, although then the torque is correspondingly higher. Consequently, the requirement of this minimum speed may then be in addition to and in addition to the requirement of sufficient operating performance described above. Preferably, the Regelan- order determines the required minimum speed also based on the given stroke speed. The required volume flow can also depend on how quickly the work is to be carried out. Likewise, it is preferred that the control arrangement determines the target speed so that it corresponds at least to the minimum speed. It may be that the control arrangement based on the predetermined lifting speed a minimum

Volume flow of the flow rate of the flow gearbox determines and the Minimum speed determined based on the minimum volume flow. Correspondingly, the minimum speed is the lowest speed at which the flow gearbox driven by the diesel engine can provide the minimum volume flow.

There may be situations in which the underground vehicle performs neither a travel movement nor a working activity of the hoist. Then the diesel engine can also be operated at idle. Therefore, a further preferred embodiment is characterized in that the control arrangement sets to a standstill signal, the target speed to a predetermined idle speed. The standstill signal may be an arbitrary signal in principle, which indicates such an idle situation. It is further preferred that the control arrangement sets the setpoint speed to a predetermined idling speed in the event of the absence of specification of a positive driving speed and the absence of specification of a working activity. It may be, for example, that the standstill signal is triggered upon actuation of a parking brake of the underground vehicle and / or opening a driver's cab door of the underground vehicle. For both the actuation of the parking brake and the opening of the driver's cab door are at least strong indications that no operation by the vehicle user will occur.

There is regularly a speed or a speed range in which a respective diesel engine can be operated particularly efficiently. This speed or this speed range then corresponds - in absolute terms - to the full-load characteristic curve of the rotary motor - that is to say with unthrottled supply of fuel - a particularly efficient operating point. But also on the other load characteristics of the diesel engine - ie with different throttled supply of fuel - is regularly the same speed or the same speed range comparatively particularly efficient in the context of the respective load characteristic. Consequently, it is expedient to counteract fluctuations in the required power that by varying the fuel supply as a manipulated variable (ie by changing the respective valid load characteristic), the output torque is changed, while the changes in speed are minimized. Such as particularly efficiently identified speed of the diesel engine can also be referred to as a preferred speed. Accordingly, it is provided according to a preferred embodiment that the control arrangement tion sets the target speed to a predetermined preferred speed, in particular when the preferred speed corresponds to at least the minimum speed. It is then necessary that the required volume flow at the preferred speed can be provided for the given work activity. Preferably, the control arrangement sets the target speed to the predetermined preferred speed, if further a positive driving speed or a working activity is predetermined. Because if neither a (non-zero) driving speed nor the execution of a work activity has been specified, the power delivered at the preferred speed will be regularly too high and rather offer an operation of the diesel engine at idle. Also preferably, the control arrangement sets the target speed to the specific preferred speed, if further provides an operating point of the diesel engine at the preferred speed, the required operating power. It may be that the required operating power can not be provided at the preferred speed, but only at a higher speed. In particular, it is preferred that the control arrangement adjusts the diesel engine to the operating point with the preferred speed and the load characteristic curve, which provides the required operating power and has the lowest fuel consumption, in particular per unit time. Regularly, but not always, this will be the load curve with the lowest setting of the supply of fuel to the diesel engine - among the load characteristics under consideration.

A preferred embodiment is characterized in that the preferred speed is above a torque maximum speed of a full load characteristic of the diesel engine. In this case, the maximum torque rotational speed is that rotational speed at which the maximum torque is output by the diesel engine on the full load characteristic curve-that is to say with essentially unrestricted supply of fuel. Preferably, the preferred speed is above a torque maximum speed substantially all of the characteristics of the diesel engine. By the preferred speed is above the torque maximum speed, it is given a lower torque, which is preferred then applies to all load characteristics. This has the effect that when operating at the preferred speed to a - moderate - increase in the required torque, the speed is automatically reduced and the diesel engine outputs a higher torque. The diesel engine is not stifled automatically in such a situation. A further preferred embodiment is characterized in that the preferred speed is less than 110% of the maximum torque speed of the full load characteristic. In other words, the preferred speed is less than 10% above the maximum torque speed. In this way, both a comparatively high torque and a comparatively high efficiency at the preferred speed is guaranteed. Accordingly, it is preferably provided that the torque at the preferred speed on the full load characteristic curve is at least 90%, in particular at least 95%, of the torque at the maximum torque rpm on the full load characteristic curve.

According to a preferred embodiment, it is provided that the drive arrangement can move the downhole vehicle at a maximum speed that is variable up to a maximum speed, and that the ratio range of the fluid transmission allows the downhole vehicle to travel at any speed up to the maximum speed, essentially at the preferred speed of the diesel engine to move. It is further preferred that the transmission range of the fluid transmission, in particular also the torque at the preferred speed on the full load characteristic curve, makes it possible to accelerate the underground vehicle from standstill up to the maximum speed. In this way, it is ensured that all speed requirements for the underground vehicle and all speed changes can be satisfied without the diesel engine having to be operated with a substantial deviation from the preferred speed.

A preferred embodiment is further characterized in that the driving arrangement comprises a hydraulic motor which can be acted upon by the hydraulic fluid for moving the underground vehicle. The proposed self-propelled underground vehicle has a hoist with at least one implement, a drive assembly for moving the underground vehicle, a drive assembly for driving the hoist and the drive assembly, which drive assembly comprises a flow gear and a diesel engine and a control arrangement for driving the drive assembly. The proposed self-propelled underground vehicle is characterized in that it has an input arrangement for predetermining by a vehicle user both a travel speed of the underground vehicle and a working activity of the hoist to be executed.

The proposed self-propelled underground vehicle is further characterized in that the control arrangement is adapted to regulate the diesel engine based on a respective predetermined by the vehicle user through the input device driving speed and work activity.

Preferred embodiments of the proposed self-propelled underground vehicle correspond to the preferred embodiments of the proposed method for operating a self-propelled underground vehicle and vice versa.

Further advantageous and preferred embodiments, features and properties will become apparent from the following specific description with reference to the figures. The only one embodiment reproducing drawing shows Fig. 1 is a schematic view of a proposed self-propelled underground vehicle and

FIG. 2 shows a schematic illustration of load characteristics of the diesel engine of the self-propelled underground vehicle of FIG. 1.

In the in Fig. 1 self-propelled underground vehicle 1 is specifically a loader la with a hoist 2, which hoist 2 in the present case has a blade 3a as a working device 3. Likewise, the underground vehicle 1 has a driving arrangement 4 with which the underground vehicle 1 can be moved at a speed that is at most Vmax. Specifically, the drive assembly 4 is a hydraulic fluid which can be acted upon by hydraulic fluid. Likewise, the underground vehicle 1, a flow gear 6 and a diesel engine 7, which are part of a drive assembly 5 of the underground vehicle 1. The flow gear 6 is presently a continuously variable hydrostatic transmission. Next, the underground vehicle 1, a control arrangement 8 for driving the flow gear 6 and the diesel engine 7 and an input device 9. This is a control panel, with which a vehicle user 10 both a driving speed and a work to be performed of the blade 3a, z. B. a lifting movement, can pretend. A direct control of the diesel engine 7 by the vehicle user 10 as known from the prior art, for. B. by pressing a foot pedal for adjusting a diesel engine 7 supplied amount of fuel, however, is not provided. On the basis of the vehicle speed specified by the vehicle user 10 and the work to be performed by the hoist 2 - in this case the bucket 3a as work implement - the control arrangement 8 determines a setpoint speed 11 of the diesel engine 7, which setpoint speed 11 is here specifically 1550 rpm and in the Fig. 2 is marked. Here also an execution time is specified by the vehicle user 10, within which the execution of the work is to be completed.

By adjusting the amount of fuel supplied to the diesel engine 7, the control assembly 8 controls the diesel engine 7 to this target speed 11. In this case, each such setting corresponds to one of the load characteristics 13a, b, c shown in FIG. 2, wherein the respective load characteristics the torque 21st represent over the speed 14. These load characteristics 13a, b, c are also stored in a data memory 18 of the underground vehicle 1 together with an efficiency curve over the rotational speed 14 for each load characteristic 13a, b, c, so that for each operating point 12, the efficiency at this operating point 12 can be determined. The uppermost load characteristic 13a forms the full-load characteristic curve 15 with unthrottled supply of fuel, with the two other load characteristics 13b, c correspondingly lower supply of fuel. For the full-load characteristic curve 15, the power curve 15a is also above the rotational speed 14 in FIG. 2 shown. In the present example, such a throttled supply of fuel takes place, which is why the operating point 12 corresponds to the point on the load curve 13b at the setpoint speed 11.

In addition to the hoist 2 and the drive assembly drives the drive assembly 5 and a hydraulic steering device 16 and a cooling device 17, both from the downhole vehicle 1, for cooling the fluid transmission 6.

The regulation of the diesel engine 7 by the control arrangement 8 takes place in detail as follows:

In a first step, it is checked whether a standstill signal is present and whether a non-zero driving speed or a work activity has ever been specified. Such a standstill signal can be triggered for example by actuation of a - not shown here - parking brake of the underground vehicle 1. In such a case, it can be assumed that the underground vehicle 1 is in a state of rest. Thus, if such a standstill signal or there is neither a specification of a positive driving speed or a work, then the target speed 11 is set to an idle speed 19 - and according to the diesel engine 7 regulated to this - which is present example at 700 U / min , So there is only little power delivered, whereby the fuel consumption is low and the generation of waste heat is minimized. If there is no standstill signal and a driving speed or a working activity is specified, a required operating power is determined, which for the execution of the work activity in the specified execution time or lifting speed, for the movement of the underground vehicle 1 and for the operation of the steering device 16 and the cooling device 17 is required as a whole. In this case, the current driving speed of the underground vehicle 1 can also be taken into account, since an acceleration requirement and thus a power requirement can result from a comparison with the predefined driving speed. Likewise, the required for the execution of the work in the specified execution time minimum volume flow of the flow gear 6 is determined and determines a minimum speed of the diesel engine 7.

A predetermined preferred speed 20, which corresponds here to 1550 rpm, is stored in the data memory 18. It is a speed 14 determined in advance in relation to the special diesel engine 7, which has been determined. Specifically, this preferred speed 20 is slightly above that speed - here referred to as the maximum torque speed 22 - in which the torque 21 of the full load curve 15 is maximum. This torque maximum speed 22 is here 1450 rpm and leads to a torque 21 of 1400 Nm on the full load characteristic 15. At the preferred speed 20 of 1550 rpm on the full load characteristic curve 15, however, the torque 21 is 1370 Nm.

First, it is checked whether the above-specified required operating power - which is 150 kW here by way of example - can be provided at the preferred speed 20. This is the case when the power output at the preferred speed 20 on the full load characteristic 15, which power is shown as the power curve 15a in FIG. 2 here 220 kW, at least this required operating performance corresponds, so what is the case here. The required operating power can be provided even at the preferred speed 20 with limited supply of fuel and thus with lower load than the full load characteristic 15.

Second, it is checked whether this preferred speed 20 is at least as high as the above-determined minimum speed, which in the present embodiment is also to be answered in the affirmative. Then, the target speed 11 is set to this preferred speed 20. By the control arrangement 8, the diesel engine 7 is then operated at the load characteristic 13b below the full load characteristic 15, since - as already stated - the output power at the target speed 11 on the full load curve 15 would far exceed the required operating line.

In principle, there are then several possible operating points 12 on which the diesel engine 7 could be operated to deliver the required operating power. However, the operation comparatively close to the torque maximum and thus with relatively low speed 14 leads to lower energy consumption than the operation with a lower torque 21 and higher speed 14. Likewise, the control arrangement 8 reacts to fluctuations in the required operating power preferably by adjusting the load characteristic 13a, b , c, the diesel engine 7 in contrast to the change in the rotational speed 14. Likewise, the flow gear 6 is due to its wide range of translation in Zu- In cooperation with the driving arrangement 4, it is possible to move the underground vehicle 1 essentially at this preferred speed 20 in the entire area up to the maximum speed and to accelerate it to an arbitrary speed in this area.

If the preferred speed 20 is smaller than the minimum speed, then the setpoint speed 11 would be set to this minimum speed and, mutatis mutandis, the appropriate load characteristic 13a, b, c will be determined to deliver the required operating power.

Claims

claims

1. A method for operating a self-propelled underground vehicle (1), which underground vehicle (1) a hoist (2) with at least one implement (3), a driving arrangement (4) for moving the underground vehicle (1), a drive arrangement (5) for driving the hoisting gear (2) and the driving arrangement (4), which drive arrangement (5) has a flow transmission (6) and a diesel engine (7) and a control arrangement

(8) for driving the drive assembly (5), characterized in that the downhole vehicle (1) is an input device

(9) for presetting by a vehicle user (10) both a traveling speed of the downhole vehicle (1) and a work operation to be performed by the hoist (2), and in that the control arrangement (8) is based on a respective one of the vehicle user (10) through the input device (9) predetermined driving speed and work activity controls the diesel engine (7).

2. The method according to claim 1, characterized in that the control arrangement (8) determines a setpoint speed (11) of the diesel engine (7) and the diesel engine (7) to this target speed (11) controls, preferably, that the control arrangement (8) the variable supply of fuel regulates the diesel engine (7), in particular regulates the diesel engine (7) to the setpoint speed (11), more particularly that the control arrangement (8) sets a ratio of the fluid transmission (6) such that at the setpoint speed ( 11) the driving assembly (4) moves the underground vehicle (1) at the predetermined driving speed.

3. The method according to claim 1 or 2, characterized in that the by the vehicle user (10) by the input device (9) predetermined work activity includes a predetermined stroke speed of the work, preferably, which stroke speed defines a execution time for the completion of the specified work activity.

4. The method according to any one of claims 1 to 3, characterized in that the control arrangement (8) based on a required operating performance determined on the predetermined driving speed and based on the predetermined work, preferably also based on the predetermined lifting speed, determines that the control arrangement (8) based on the specific operating performance determines an operating point (12) of the diesel engine, which operating point by a speed (14) and a load characteristic (13a, b, c) of the diesel engine (7) is defined and at which operating point the diesel engine (7) provides at least the required operating power and that the control arrangement (8) adjusts the diesel engine (7) to the specific operating point.

5. The method according to any one of claims 1 to 4, characterized in that the downhole vehicle (1) one of the drive assembly (5) driven hydraulic steering device (16) for directing the Untertage- fahrzeus (1) and one of the drive assembly (5) powered cooling device (17) for cooling the fluid transmission (6), preferably that the lifting mechanism (2) comprises a plurality of working devices (3) for which the input device (9) by the vehicle user (10) specifies a respective work activity to be performed, in particular, that the control arrangement (8) also provides the required operating power based on a respective power for operating the steering device (16) and for operating the cooling device (17), more particularly based on the respective predetermined work activities of the plurality of working devices (3), certainly.

6. The method according to claim 5, characterized in that in a data memory (18) of the underground vehicle (1) has a set of load characteristics (13a, b, c), which preferably each one of the load characteristic (13a, b, c) associated setting the supply of fuel to the diesel engine (7) are marked, are deposited for the diesel engine (7) and that the operating points (12) along the stored load characteristics (13a, b, c) each have a fuel consumption, in particular per unit time, assigned in particular that the control arrangement (8) for determining the operating point (12) of the diesel engine (7) from the set of stored load characteristics (13a, b, c) selects that load characteristic (13a, b, c) at which the operating point (12 ) has the lowest fuel consumption, especially per unit time, at the particular operating power.

7. The method according to any one of claims 1 to 6, characterized in that it is in the flow gear (6) is a hydrostatic transmission, which hydrostatic transmission from the diesel engine (7) output power variably, preferably continuously, in a flow of hydraulic fluid of the hydrostatic transmission converts.

8. The method according to any one of claims 1 to 7, characterized in that the control arrangement (8) determines a required minimum speed of the diesel engine (7) based on the predetermined work activity, in particular based on the predetermined lifting speed, preferably that the Control arrangement (8) the target speed (11) determined so that it corresponds to at least the minimum speed, preferably, that the control arrangement (8) based on the predetermined lifting speed determines a minimum volume flow of the flow rate of the flow gear (6) and the minimum Speed determined based on the minimum volume flow.

9. The method according to claim 8, characterized in that the control arrangement (8) to a standstill signal, preferably to a standstill signal in the absence of specification of a positive driving speed and lack of specification of a working activity, the target speed to a predetermined idle speed (19 ), in particular, that the stop signal is triggered upon actuation of a parking brake of the underground vehicle (1) and / or opening a driver's cab door of the underground vehicle (1).

10. The method according to any one of claims 1 to 9, characterized in that the control arrangement (8) sets the target speed (11) to a predetermined preferred speed (20), in particular, when the preferred speed (20) at least the Minimum speed corresponds, preferably, and when a positive driving speed or a working activity is predetermined, more preferably, and when an operating point (12) of the diesel engine (7) at the preferred speed (20) provides the required operating power, further in particular the control arrangement (8) sets the diesel engine to the operating point (12) with the preferred speed (20) and the load characteristic line (13a, b, c) which provide the required drive performance and the lowest fuel consumption, more preferably per unit of time, has.

11. The method according to claim 10, characterized in that the preferred speed (20) above a maximum torque speed (22) of a full load characteristic (15) of the diesel engine (7), preferably, that the preferred speed (20) above a Torque maximum speed (22) substantially all load characteristics (13a, b, c) of the diesel engine is located.

12. The method according to claim 11, characterized in that the preferred speed (20) is less than 110% of the maximum torque speed (22) of the full load characteristic (15), preferably that the torque (21) at the preferred speed (20). on the full load characteristic (15) is at least 95%, in particular at least 90%, of the torque (21) at the maximum torque speed (22) on the full load characteristic (15).

13. The method according to any one of claims 10 to 12, characterized in that the driving assembly (4) can move the downhole vehicle (1) with a variable speed up to a maximum speed and that the transmission range of the fluid transmission (6) allows, substantially at the preferred speed (22) of the diesel engine (7) to move the underground vehicle (1) at an arbitrary driving speed up to the maximum speed.

14. The method according to claim 13, characterized in that the driving arrangement (4) has a hydraulic fluid acted upon by the hydraulic motor for moving the underground vehicle (1).

15. A self-propelled underground vehicle (1) comprising a hoist (2) with at least one implement (3), comprising a drive arrangement (4) for moving the underground vehicle (1), comprising a drive arrangement (5) for driving the hoist (2) and the Driving arrangement (4), which drive arrangement (5) comprises a flow gearbox (6) and a diesel engine (7) and comprising a control arrangement (8) for activating the drive arrangement (5), characterized in that the downhole vehicle (1) has an input arrangement (9 ) for predetermining by a vehicle user (10) both a vehicle speed of the vehicle and that the control arrangement (8) is adapted to regulate the diesel engine (7) based on a vehicle speed (10) given by the vehicle user (10) through the input device ,