JP3881978B2 - Method and apparatus for maneuvering an industrial truck - Google Patents

Description

  The present invention relates to a method and apparatus for maneuvering an industrial truck.

  German Patent No. 43 03 342 is capable of maneuvering independently of each other, and is equipped with several vehicle shafts each connected to a servo motor, maneuvering for carrying end loads and side loads on a forklift. Revealed the device. A high-speed electric motor that is very slowed down through a set of gears is equipped as a servo motor. Each maneuvering computer generates a control signal for the servo motor.

  International Publication No. 93/02906 revealed a vehicle equipped with steerable front and rear wheels with multiple control modes. The instruction issued to convert from one control mode to another is to convert each such wheel in groups. As a result, it is possible to convert from one maneuvering mode to the next maneuvering mode during movement.

  German Patent No. 39 42 494 discloses a rear wheel steering device for a four wheel steering vehicle. In order to correct the linear movement, a measuring device that detects front wheel steering force, front wheel lateral force, and lateral acceleration of the vehicle was deployed. The correction of the wheel position is done in such a way that these forces and lateral acceleration are substantially zero.

  British Patent No. 2 232 941 A revealed a control device for a motor vehicle. In this power vehicle, the rear wheels are calculated according to the steering angle of the front wheels and the vehicle speed. In order to consider the speed, the rotational speed of the front and rear wheels is measured. The steering angle lock for the rear wheels is controlled according to the speed quotient.

  German Patent No. 39 11 453 A1 discloses a rear wheel control device that urges the rear wheel of a vehicle by a spring to bring the rear wheel into a natural position suitable for steering. The rear wheel steering mechanism adjusts the rear wheels against this resistance.

EP 0 512 591 revealed a rear wheel steering device that controls either the left or right rear wheel according to the steering angle lock of the front wheel.
German patent 43 03 342 International Publication No. 93/20906 German Patent No. 39 42 494 British Patent No. 2 232 941 A German Patent No. 39 11 453 A1 European Patent No. 0 512 591

  An object of the present invention is to provide an industrial truck equipped with a maneuvering device that allows reliable and safe operation in different maneuvering operation modes.

  According to the invention, this object is achieved by the features of claim 1. Useful forms constitute the content of the dependent claims.

The method relates to an industrial truck equipped with three or more steerable wheels that are moved in different maneuvering modes of operation by at least one maneuvering controller. An example of such a maneuvering mode is normal movement, in which all wheels are oriented at an angle of 0 ° with respect to the longitudinal direction of the vehicle in order to maneuver an industrial truck. Only the wheels of the book are controlled. On the contrary, in a modified normal movement, for example, all wheels are still oriented in an angle of 0 ° with respect to the longitudinal direction of the vehicle, but all-wheel maneuvering is performed. Further, the industrial truck is provided with a movement control device that controls driving according to a preset value. Maneuvering control devices and movement control devices belong to the control of industrial trucks. The control device can be provided as a plurality of control units that are physically separated, or can be provided integrally in one control unit. Further, a control unit such as a steering control device can perform higher rank control. In accordance with the present invention, each maneuver mode of operation comprises at least one set of movement parameters associated therewith. The movement control device controls the driving and / or braking of the industrial truck using a set associated with the actual maneuvering operation mode, which is the current maneuvering operation mode . An advantage of the present invention is that only those travel parameters that ensure safe driving performance are automatically supplied to industrial truck operators in a cost-effective manner. By selecting a set of travel parameters to reduce the risk of accidents, vehicle controllability and thus safety are improved. This solution can be implemented in an existing controller, so there is no additional cost.

  In a preferred continuous form of the method according to the invention, each set of movement parameters includes a maximum speed as the movement parameter. Preferably, the maximum acceleration is additionally provided as a movement parameter. In another advantageous form, the set of travel parameters additionally includes values for deceleration, in particular values for reverse brake and / or coasting brake. It is also preferred to provide parameters for the steering wheel gear ratio and emergency stop tilt.

  Limits by movement parameters on the maximum values of speed, acceleration and / or deceleration serve the purpose of preventing overloading or unstable positions of industrial trucks in certain maneuvering modes of operation.

  In some maneuvering modes of operation, the wheels have a basic position where the industrial truck turns substantially appropriately. Each set of movement parameters regulates the maximum speed of the drive, preferably to a speed of about 4 km / h. By controlling the speed, the centrifugal force acting on the driver and the load are surely prevented from being excessive. In this maneuvering operation mode, acceleration is restricted to 5 and delay is restricted to 3 in steps 0-9.

  The object of the present invention is also achieved by an apparatus for maneuvering an industrial truck having a maneuvering control unit and a movement control unit. The steering control unit and the movement control unit are preferably interconnected via a data bus so that data and control signals can be exchanged. In the device of the present invention, the steering control unit transmits a signal to the movement control unit, and this signal is received by the movement control unit, so that which steering operation mode and, in turn, which movement parameter, to control the drive. Informs the movement controller whether the set is supplied. In other words, it means that the movement control unit functions independently of the actual steering operation mode.

  In a preferred form, a steering wheel control device for the drive wheels generates a signal for the movement control device. In one preferred form, the CAN bus is provided as a data bus.

Otherwise, in another maneuvering mode where the basic settings of all wheels intersect at an angle of 90 ° with the longitudinal direction of the vehicle, each set of movement parameters has a maximum acceleration value. In the maneuvering mode, also known as cross-line movement, the driven wheels are located far from the center, so a significant amount of inertia occurs during excessive acceleration, which causes the vehicle body to bend and twist. there is a possibility. In order to avoid these, the maximum acceleration during the movement of the intersection line is regulated. It is preferable to increase the steering gear ratio to prevent the vehicle's sensitive response to the steering wheel lock.
Hereinafter, the method of the present invention will be described in more detail with reference to the drawings.

  By selecting a set of travel parameters to reduce the risk of accidents, vehicle controllability and thus safety are improved. This solution can be implemented in an existing controller, so there is no additional cost.

  FIGS. 1 a-1 e schematically show a view of an industrial truck 10 with a drive wheel 12 in a vehicle body 14. Furthermore, steerable load bearing wheels 16, 18 are provided on the load bearing arms 20, 22.

  FIG. 1a shows a normal movement in the basic position while the drive wheels and load bearing wheels are in a state of surrounding an angle of 0 ° with respect to the longitudinal direction A of the vehicle. Maneuvering is performed exclusively via the drive wheels during normal travel. The steering angle is limited here to ± 95 °, or a continuous steering of 360 ° is performed.

  FIG. 1b shows a slightly modified basic position of normal movement which is not different from the basic position of normal movement in FIG. 1a. However, in normal movement, four-wheel steering is performed in the arrangement indicated by the double-headed arrow. Here, in order to achieve the highest possible mobility in a very narrow space, the steering angles of the drive wheels and load bearing wheels are respectively adjusted according to the steering angle lock. Here, the steering angle lock is ± 95 ° or 360 ° continuous steering is executed.

  FIG. 1c shows the basic position of crossing line movement while the drive wheels and load bearing wheels are positioned transversely intersecting at an angle of 90 ° with respect to the longitudinal direction of the vehicle. As indicated by the double-headed arrow, the maneuver is performed via a load-bearing wheel equipped with a maneuvering control device, which takes into account the direction of movement and the current wheel position and moves the wheel position in the left or right direction. Distinguish whether or not to make changes. Left and right directions respectively refer to the line of sight from the driver's location towards the load being picked up, i.e. from the vehicle body to the load bearing arm.

  FIG. 1d shows the basic position of the wheel performing diagonal movement in the right direction. All wheels are turned to the right at an angle of 45 ° with respect to the “normal movement” basic position. As indicated by the double-headed arrow, the four-wheel steering is executed by making a difference in the steering angle between the driving wheel and the load-bearing wheel according to the steering angle lock. In connection with diagonal movement to the right, there is a further maneuver mode of operation that turns all wheels to the left at an angle of 45 ° in the basic setting.

  Although not shown, there is also a parallel movement in which the wheels are aligned with the longitudinal direction of the vehicle at the basic position. Four-wheel maneuvering is performed during parallel movement as well as during modified normal movement. Here, however, the maneuver is performed so that all three wheels are moved at the same maneuver angle. The translation operation mode allows the vehicle to move in the diagonal and crossing directions without changing the longitudinal axis of the vehicle.

  FIG. 1e shows a maneuver mode of operation that allows a turn in minimal space. The drive wheels are arranged transverse to the longitudinal direction of the vehicle, and the load bearing wheels are arranged so that the industrial truck moves around a center of rotation M provided between the wheels. In this case, the control wheel is in a stopped state.

  FIG. 2 is a block diagram showing the flow of control. The control of an industrial truck equipped with two load bearing wheels and one drive wheel comprises three independent steering control devices 24, 26, 28. The steering control devices 24 to 28 are provided for each wheel. The steering angle set point is calculated in the central control unit 30. The control unit 30 is given an actual steered wheel position 32 determined by a set point sensor system 34. Advantageously, this control is integrated into one of the steering control devices.

  Furthermore, the control unit 30 is given an accelerator pedal position 36 via a potentiometer 38. Such data is processed in the movement controller 40 according to the actual set of movement parameters 42.

  In this example, the set of travel parameters is not pre-determined by the central control unit 30, but the driving wheel steering controller 28 supplies a so-called CAN telegram 44 assigned by the CAN bus 46. However, it is possible for the control unit 28 to function as the master control unit of other control units, and possibly also as a movement control unit, so that the task of the control unit 30 can be taken. In this case, the CAN bus means a control area network bus. A message for the actual maneuvering operation mode arrives at the movement control device 40 via the data line 48. Next, the movement control device 40 selects each set of movement parameters in response to the message for this actual maneuvering operation mode.

  The movement parameters include movement speed, acceleration, reverse brake, and coasting brake. It can be seen that the one or more movement parameters are not the same in different sets of movement parameters. Similarly, several maneuvering modes of operation can use the same set of travel parameters. The maneuvering operation mode “change direction within the minimum space” limits the speed of movement to about 4 km / h, and consequently limits the centrifugal force generated against the driver and the load. At the same time, in the crossing line movement operation mode, the acceleration and movement speed of the industrial truck is restricted to about 8.5 km / h. A maximum movement speed of about 12 km / h is possible with normal movement.

  As an example, a set of movement parameters for the steering operation modes of circular movement, normal movement, modified normal movement, cross line movement, parallel movement, and diagonal movement will be shown below as examples. Each set of parameters has the following quantities: acceleration, coasting brake, reverse brake, travel speed, emergency stop tilt, steering wheel gear ratio. The emergency stop tilt and the control wheel gear ratio are two different decelerations, while the absolute amount, ie km / h, is pre-determined for the maximum travel speed within the travel parameters. Further, the steering wheel gear ratio is given as a correction gear ratio and a movement parameter. Similar to the emergency stop inclination, acceleration and delay by coasting brake and reverse brake are given as parameters in the range of 0 to 9 stages. The display with parameters has the advantage that values can be determined in advance and can be set independently for each drive, battery, etc. The emergency stop inclination is a movement parameter that represents the strength of braking in an emergency.

  As an example, a set of parameters for different maneuvering operation modes is shown.

The basic settings of the wheels for various maneuvering modes are shown. The block diagram of a control part is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Industrial truck 12 Drive wheel 14 Vehicle main body 16,18 Load-bearing wheel 20,22 Load-bearing arm 24,26,28 Steering control apparatus 30 Central control unit 40 Movement control apparatus

Claims (6)

A method for maneuvering an industrial truck, comprising a control unit comprising at least a maneuvering control device and a movement control device, wherein the maneuvering control device has different maneuvering operation modes for three or four steerable wheels. These steered wheels are controlled starting from the base position,
Each steering operation mode is associated with a set of mobile parameters including a value of at least the maximum speed and the maximum acceleration and maximum deceleration,
A method of controlling driving and braking of the industrial truck using the set of movement parameters associated with an actual maneuvering operation mode in which the movement controller is a current maneuvering operation mode.
The wheel has a in one basic position of the steering operating mode, as a result, the method according to claim 1, in accordance with the respective set of movement parameter for regulating the maximum speed, are appropriately diverted . 3. The method of claim 2 , wherein the maximum speed is regulated to about 4 km / h. The movement parameter has a maximum acceleration to a specific maneuvering operation mode, in the basic position of the particular steering mode of operation, that all the wheels intersect at an angle of 90 ° to the longitudinal direction of the vehicle The method of claim 1, characterized in that:
An apparatus for maneuvering an industrial truck, comprising a control unit including at least a steering control device and a movement control device, wherein the steering control device has different steering operation modes for three or four steerable wheels. These steered wheels are controlled starting from the base position,
Each steering operation mode is associated with a set of mobile parameters including a value of at least the maximum speed and the maximum acceleration and maximum deceleration,
Controlling the driving and braking of the industrial truck using the set of movement parameters associated with the actual maneuvering mode in which the movement controller is the current maneuvering mode;
The steering control device and the movement control device are interconnected by a data bus, the steering control device supplies a signal, and the signal is received by the movement control device. Informing the movement control device whether or not 6. The device of claim 5 , wherein a steering control device that directs a single drive wheel generates a signal for the movement control device .

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