Self-propelled road construction machine, in particular road roller, and methods for driving and steering a road construction machine

Abstract

Self-propelled road construction machine, in particular road roller, - with a drive unit (60), - with a steering device (62), - with a control unit (30) for the drive system (60) and the steering system (62), and - wherein a control element (8) for driving speed and steering generates the control signals for the driving drive (60) and the steering device (62) depending on the direction of the control movement acting on the control element, characterized in that at least in manual operation of the control (30) sensors detect the magnitude and direction of the force exerted on the control element (8) and that the control (30) generates a control signal for acceleration, deceleration, or emergency stop, as well as for steering, depending on the detected angle relative to the direction of travel and the magnitude of the force.

Description

[0001] The invention relates to a self-propelled road construction machine, in particular a road roller according to the preamble of claim 1, and to a method for driving and steering a road construction machine according to the preamble of claim 9.

[0002] A road construction machine of this type is known from EP 1 573 134 A1 (published as WO 2004 / 059 088 A1). The road roller operates, for example, behind a paver that paves and pre-compacts asphalt material. The road roller repeatedly passes over the surfaces paved by the paver to achieve final compaction and evenness. During this process, the direction of travel is frequently changed. The proportion of forward and reverse travel is generally approximately equal. To operate the road roller safely, the key controls, such as the direction sensor (steering wheel, joystick) and the drive lever for selecting the direction of travel and speed, must be clearly assigned to the direction of travel for the operator.

[0003] From EP 1 573 134 A1 it is also known to integrate the control element for driving speed and steering into a rotating driver's seat, wherein the direction of movement of the control element corresponds to the direction of travel of the road construction machine in each seat rotation position.

[0004] The invention is based on the object of improving the control options of a self-propelled road construction machine, in particular a road roller, and of a method for driving and steering a road construction machine and thereby increasing operational safety.

[0005] The features of claim 1 and claim 9 serve to solve this problem.

[0006] The invention advantageously provides that, at least during manual operation of the control, sensors detect the magnitude and direction of the force exerted on the operating element, and that the control generates a control signal for acceleration, deceleration, or an emergency stop, as well as for the steering, depending on the detected angle relative to the direction of travel and the magnitude of the force.

[0007] This has the advantage that, in manual mode, acceleration can be controlled by the driver's force. This allows for more sensitive control. Depending on the force applied, it can detect whether high or low acceleration, low deceleration, high deceleration, or even an emergency stop is desired.

[0008] In a preferred embodiment, it is provided that the controller generates a control signal for a low acceleration in the direction of travel when a first force threshold value is exceeded in a first angular range relative to the direction of travel, and generates a control signal for a higher acceleration when a second force threshold value is exceeded in a second angular range which is preferably narrower relative to the first angular range.

[0009] Furthermore, if the first force threshold value in the first angular range is undershot up to a third force threshold value in the remaining angular range outside the first angular range, the controller can generate a control signal for a slight deceleration.

[0010] In addition, if the third force threshold is exceeded up to a fourth force threshold in the remaining angular range outside the first angular range, the controller can generate a control signal for a high deceleration.

[0011] Finally, if the fourth force threshold is exceeded in the remaining angular range outside the first angular range, the controller can generate a control signal for an emergency stop.

[0012] When a desired operating speed of the road roller is reached, the control system can switch to automatic operation upon a first switching command, in which the current control signals for the drive and steering are automatically kept constant.

[0013] The driver can accelerate or decelerate by applying force to the control element, e.g., a joystick-like control lever. The direction and magnitude of the force are evaluated in relation to the direction of travel. Upon reaching the desired speed, the driver confirms this by pressing a button. The machine now travels at a constant speed until acceleration or deceleration is initiated by applying force to the control element.

[0014] It is preferably provided that the control switches from automatic operation to manual operation when the level of the detected force on the control element exceeds a predetermined fifth force threshold value in the first angular range.

[0015] Preferably, the control element is integrated into a rotating driver's seat.

[0016] The direction of movement of the control element in each seat rotation position corresponds to the direction of travel of the road construction machine.

[0017] In the control element, the control signals for the direction of travel and the steering can be continuously corrected depending on the angle of rotation of the current seat rotation position.

[0018] In the following, an embodiment of the invention is explained in more detail with reference to the drawings.

[0019] They show: Fig. 1 a schematic representation of a road construction machine according to the invention with an operating element with force evaluation, Fig. 2 the effects of operating the control element in an embodiment with a rotating driver’s seat, Fig. 3 a control element according to the state of the art, and Fig. 4 the direction of movement of the control element in the case of a rotating driver’s seat.

[0020] In Fig. Figure 1 schematically shows a road roller 1 with two roller drums 2, 3, at least one of which is steerable. The roller drums 2, 3 are connected to each other via a chassis 4, on which a driver's cab for an operator is arranged.

[0021] A rotating driver's seat 5 with an integrated control unit for driving is arranged in the driver's cab. The control unit preferably has an operating lever 8, the functions of which are to be determined in detail in conjunction with Fig. 3 will be explained.

[0022] Although the schematic representation in Fig. 1 shows an embodiment in which the driver's seat is rotatable, it is understood that the invention is also applicable to road rollers without a rotatable driver's seat.

[0023] The evaluation of the control force exerted on the control element 8 is carried out in two dimensions with the help of force sensors 28, 29, as shown for example in Fig. 3 are shown.

[0024] The two-dimensional evaluation of the control force makes it possible to detect the magnitude and direction of the force exerted on the control element 8, wherein a controller 30 generates a control signal for acceleration, deceleration or emergency stop, as well as for the steering, depending on the detected angle relative to the direction of travel and the magnitude of the force.

[0025] The direction of the force is always evaluated parallel to the direction of travel. Even with a rotating driver's seat, it is possible to always evaluate the direction of force parallel to the direction of travel. This only requires angular information regarding the seat rotation position relative to the vehicle's steering axis.

[0026] In Fig. 1 shows a schematic representation of how the detected force in the direction of travel is evaluated. The schematic representation in Fig. Figure 1 shows the angle- and force-dependent evaluation of the force exerted on the control element 8. Viewed in the forward direction, for example, two force thresholds 40, 42 are initially provided. When exceeded, a slight acceleration is initially triggered in a first angular range 44, followed by a higher acceleration in an angular range 46 that is preferably narrower than the first angular range 44. The slight acceleration is indicated by a "+" in the angular range 44, and the high acceleration is indicated by a "++" in the angular range 46. It is understood that the angular ranges 44 and 46 can also be of equal size.

[0027] The angular ranges are angularly limited, wherein preferably a larger angular segment for evaluating the control force can be set for the angular range 44 than for the second angular range 46. The second angular range 46 for high acceleration can, for example, have an angular range of less than ± 45° relative to the direction of travel, preferably approximately ± 35°, thus covering, for example, a total angular range of 50° to 80°.

[0028] The angular range 44 of low acceleration comprises a total angular range of preferably over 90°, for example 80° to approximately 150°.

[0029] If the control force is applied in a direction that lies outside the specified force threshold 40 in the narrower angular range 46, a change to a higher acceleration takes place.

[0030] If the evaluation of the force exerted on the control element 8 results in a fall below the first force threshold 40, a low delay is set. The field with the low delay in the entire angle range 44, 48 is in Fig. 1 marked with “-”.

[0031] In the remaining angular range 48 outside the first angular range 44, a low deceleration is set as long as a third force threshold 54 is not exceeded. If this threshold is exceeded, a high deceleration "--" is set.

[0032] The force thresholds 42 and 54 can be equal in magnitude.

[0033] If a fourth force threshold value 56 is exceeded in the remaining angular range 48 outside the first angular range 44, an emergency stop “---” is initiated.

[0034] In automatic mode, it can be provided in the first angle range 44 that forces on the operating element 8 above a specified force threshold value 52 necessarily switch the automatic mode to manual mode.

[0035] In manual mode, the driver accelerates or decelerates the operating speed by applying force to control element 8. Upon reaching the desired operating speed, the driver can confirm this by pressing a button. The road roller then travels at a constant speed until acceleration or deceleration is triggered by applying force to control element 8.

[0036] Fig. 2 and Fig. 3 show the prior art according to EP 1572 134. In the illustrated case, the control element 8 is deflected in the direction of arrow 20 and remains in this position - the machine travels in the direction of the arrow. A movement of the control lever 8 in the direction of arrow 18 leads to a steering movement of the drum - the machine travels to the left. If the driver's seat is rotated by 90° while driving, the control element 8 is adjusted such that its deflection direction continues to correspond to the direction of travel. The direction of movement of the control element 8 for the steering also corresponds to the direction of movement of the road roller 1. The same applies to the rotation of the driver's seat 5 by 180°. The driver's seat 5 can still be freely rotated beyond 180°.

[0037] Fig. Figure 3 illustrates the control element 8 with its components, operating functions, and the device for transmitting the rotational movement of the driver's seat 5 to the control unit. The control element 8 has switching devices 12 for the rear-wheel steering or crab steering, switching devices 14 for switching the vibration on and off, switching devices 16 for unlocking the driving lock, as well as switching devices 18 with two degrees of freedom for specifying the steering direction and a switching device 20 for the direction of travel. To make it easier for the operator to distinguish between steering movement and driving movement during the control element deflection, the steering movement is actuated against a spring force to the neutral position, and the driving deflection is actuated against a friction force. Preferably, the essential operating functions mentioned are integrated into the control element 8. The housing 22 is firmly connected to the driver's seat 5.A deflection of the operating lever 8 in the direction of driving or steering leads to a deflection of the respective gate for the driving or steering movement, not shown in the drawing.

[0038] The deflection of the control element 8 for steering and driving is detected by two potentiometers 32 (x-direction) and 34 (y-direction) in the universal joint 28 (pivot point of the control lever 8). A third potentiometer 36 is mounted below the swivel wheel 26 on its axis of rotation and measures the angle of rotation of the swivel wheel 26 relative to the housing 22 and thus the seat position. The potentiometers 32 and 34 are connected to the housing 22 in a rotationally fixed manner, i.e., a rotation of the driver's seat 5 changes the assignment of the respective potentiometers 32 and 34 to the drive lever deflection. For example, in the initial seat position, the steering deflection of the control lever is detected by the potentiometer 34 from 8% to 100%. The force sensors 29, 30 detect the forces acting on the control element 8 two-dimensionally.

[0039] Fig.4 also explains the direction of movement of the control element 8, whereby the arrow represents the direction for forward travel for all seating positions.

Claims

[1] Self-propelled road construction machine, in particular road roller, - with a drive (60), - with a steering device (62), - with a control (30) for the drive (60) and the steering device (62), and - wherein an operating element (8) for driving speed and steering generates the actuating signals for the drive (60) and the steering device (62) depending on the direction of actuating movement acting on the operating element, characterized by that at least during manual operation of the control (30) sensors detect the level and direction of the force exerted on the operating element (8) and that the control (30) generates a control signal for acceleration, deceleration, or an emergency stop, as well as for the steering, depending on the detected angle relative to the direction of travel and the level of the force. [2] Device according to claim 1, characterized bythat the controller (30) generates a control signal for a low acceleration (+) in the direction of travel when a first force threshold value (40) is exceeded in a first angular range (44) relative to the direction of travel, and generates a control signal for a higher acceleration (+) when a second force threshold value (42) is exceeded in a second angular range (46) which is preferably narrower relative to the first angular range (44). [3] Device according to claim 2, characterized by that the controller (30) generates a control signal for a slight (-) deceleration when the first force threshold value (40) in the first angular range (44) is undershot up to a third force threshold value (54) in the remaining angular range (48) outside the first angular range (44). [4] Device according to claim 2 or 3, characterized bythat the controller (30) generates a control signal for a high deceleration (--) when the third force threshold value (54) is exceeded up to a fourth force threshold value (56) in the remaining angular range (48) outside the first angular range (44). [5] Device according to one of claims 1 to 4, characterized by that the controller (30) generates a control signal for an emergency stop (---) when the fourth force threshold value (56) is exceeded in the remaining angular range (48) outside the first angular range (44). [6] Device according to one of claims 1 to 5, characterized by that the control (30) switches to automatic operation upon reaching a desired operating speed in response to a switching command, in which the current control signals for the drive (60) and the steering are automatically kept constant. [7] Device according to claim 6, characterized bythat the control (30) switches over from automatic operation to manual operation when the level of the detected force on the operating element (8) exceeds a predetermined fifth force threshold value (52) in the first angular range (44). [8] Device according to one of claims 1 to 7, characterized by that the control element (8) is integrated into a rotatable driver's seat (5) and that in the control element (8) the control signals for the direction of travel and the steering can be continuously corrected depending on the angle of rotation of the current seat rotation position. [9] Method for driving and steering a road construction machine, in particular a road roller, with an operating element (8) for driving operation, characterized bythat the level and direction of the force exerted on the control element (8) are detected during manual operation, and that a control signal for acceleration, deceleration, or an emergency stop, as well as for steering, is generated depending on the detected angle relative to the direction of travel and the level of the force. [10] Method according to claim 9, characterized by that when a first force threshold value (40) is exceeded in a first angular range (44) relative to the direction of travel, a control signal for a low acceleration (+) is generated and when a second force threshold value (42) is exceeded in a second angular range (46) which is preferably narrower relative to the first angular range (44), a control signal for a higher acceleration (++) is generated. [11] Method according to claim 10, characterized bythat when the first force threshold value (40) in the first angular range (44) is undershot up to a third force threshold value (54) in the remaining angular range (48) outside the first angular range (44), a control signal for a slight deceleration (-) is generated. [12] Method according to claim 10 or 11, characterized by that when the third force threshold value (54) is exceeded in the remaining angular range (48) outside the first angular range (44) up to a fourth force threshold value (56), a control signal for a high deceleration (--) is generated. [13] Method according to one of claims 9 to 12, characterized by that when the fourth force threshold value (56) is exceeded in the remaining angular range (48) outside the first angular range (44), a control signal for an emergency stop (---) is generated. [14] Method according to one of claims 9 to 13, characterized bythat when a desired operating speed is reached, an automatic mode can be activated in which the current control signals for the drive (60) and the steering are automatically kept constant. [15] Method according to claim 14, characterized by that in automatic mode, the system automatically switches to manual mode when the level of the detected force on the operating element (8) exceeds a predetermined fifth force threshold value (52) in the first angular range (44).

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