DE102005021415A1 - Method for damping of longitudinal oscillations of fluids in vehicle transporting containers entails feeding of antiphase control signal to influencing unit corresponding to antiphase moment to influence engine or braking torque - Google Patents

Abstract

The method for damping of longitudinal oscillations of fluids in vehicle transporting containers (12) entails the feeding of an antiphase control signal to an influencing unit (18) corresponding to an antiphase moment, and influencing a current engine torque or braking torque of an engine and/or brake system (20) by the influencing unit in dependence upon the antiphase moment in such a way that the longitudinal oscillation is damped. An independent claim is included for a device for damping of longitudinal oscillations of fluids in vehicle transporting containers by the aforesaid method.

Description

The The invention relates to a method and a device for damping of Longitudinal vibrations of liquids in vehicle transport containers and / or from these induced vehicle longitudinal vibrations according to the generic term of the claims 1 or 5.

It It is well-known that tankers when in transit are in the tank located liquid due to inertia forces in motion device and in this regard unwanted vibrations occur that are transmitted to the vehicle. Unless the through these vibrations transmitted to the vehicle forces comparatively are big, This will be done by the driver at least perceived as unpleasant. In addition, the vehicle safety thereby impaired become.

to Avoidance or at least reduction of such liquid vibrations or liquid-related Vehicle vibration is known, the liquid container in their interior with splash walls equip, which limit the mobility of the liquid in the tank and so dampening on the resulting fluid vibrations Act. It is customary the baffles in Along- and transverse direction of the container to arrange, reducing the volume of the container in two or more equal, separated parts is separated.

There the movement of the liquid mass priority longitudinal of the vehicle due to the acceleration and deceleration movements thereof is usually done in the direction of movement of the vehicle only one or two baffles, but transverse to the direction several baffles arranged. The forces generated by the movement of the liquid act on the transverse surge walls so on the container walls, that the transport container in the longitudinal direction the attachment point of the longitudinal bulkheads maximum deformed, that is, that the tensile and compressive forces here are the largest.

The through these forces can arise voltages be so high that it leads to material fatigue as well Cracks on the container walls the places of the baffle plate attachment and thus to lick the container comes. It is known to overcome these technical problems by putting the critical posts through extra stiffeners outside and inside the container reinforced are.

Regarding Liquid containers for vehicles, For example, tanks, boilers or water tanks, it is also common to provide bulkheads, which caused by the fluid movements, reduce forces acting on the container walls. This is also done with the use of bulkhead walls by means of a limitation of the motor ability the liquid, for example, by subdivision of the per se significant mass of liquid in smaller, mutually delimited masses, their hydrodynamic personnel taken from the bulkheads become.

A such for cylindrical tank container suitable baffle is perpendicular to vehicle longitudinal axis arranged and consists of several, in a plane next to each other and spaced radially with each other, and to the center of the container tapering in width profiled, so to its center line angled or curved plates. The plates are like each other in shape as well as in shape in their dimensions and profiling. Their arrangement is usually such, that according to the direction of flow the liquid either exclusively the concave profiled or only the convex profiled surfaces of the Plates can be applied are. The plates are attached on the one hand to the inner wall of the Tank container and the other hand at one in the tank center arranged inner ring.

at such a partially filled Tank container flows the liquid, for example, in a vehicle deceleration triggered by vehicle braking, at the arched End faces of the Tank container high, swings back under strong vortex formation and hits on the plates of the baffle on where the currents due to the profiling the baffle are broken, deflected and swirled as well a part of the flow energy in heat energy is converted.

The Special profiling of the panels is also causal for the ever after flow direction different resistance coefficients, so that resonance phenomena be avoided and ensured by the vibration overlay damping is what an off-center Arrangement of the baffle in the tank container is supported.

A certain partitioning effect is provided for with a tank wagon and in the patent specification DE 1 059 490 C can be achieved described device. According to this technical solution, the baffle plate, which is also arranged perpendicularly to the vehicle longitudinal axis, is formed by two flat segments fastened to the boiler in the upper and lower regions of the container cross section and a middle profiled segment, which forms the connecting flat segments with each other.

consisting from several perpendicular, at a distance to each other and respectively at an angle of 180 ° of Full circle of 360 ° offset from each other arranged V-shaped Elbows, points the profiled segment covered Through openings on, by which upon impact of the liquid, in particular at only partially filled Boiler, longitudinal force components the Schwellbleches be set off, the opposite to each other are and cancel as far as possible. At the same time the flowing liquid distracted and their kinetic energy by the impact on the Kesselmantel consumed.

The As already mentioned, the devices described above are in particular intended for cylindrical liquid containers, which is stable in itself, that is represent self-supporting, form and torsion-resistant tubes. adversely however, that these devices are longitudinal vibrations of the vehicle not completely can prevent. These Vibrations are for the driver very uncomfortable and for the driving safety of the vehicle not conducive. A disadvantage on the stand Furthermore, the technique is an inherently high material and assembly costs for the devices for fluid calming. In addition, the effect of vibration damping in previously known Devices also from the degree of filling the liquid container is dependent. Another disadvantage of the disclosed devices lies in the fact that that the damping effects the baffles described at all only at a predetermined degree of filling the liquid container effective become.

Therefore the invention has the object, a method and a Device to imagine the longitudinal vibrations of liquids in vehicle transport containers, especially in partially filled Effectively dampen the condition of the same.

The solution This object is apparent from the features of the independent claims 1 and 5 while advantageous embodiments and developments of the invention the Subclaims removable are.

Of the Invention is based on the knowledge that by generating and causing one to be generated by the liquid in the vehicle container Vehicle vibration antiphase vehicle vibration the fluid-related Neutralize vehicle acceleration at least in the vehicle longitudinal direction leaves.

• – Erfassen von Längsschwingungen der Flüssigkeit bzw. des Fahrzeugs durch ein Schwingungserfassungsmittel und Zuführen eines Schwingungserfassungssignals an eine Berechnungseinheit,
• – Erfassen der Fahrzeuggeschwindigkeit durch ein Geschwindigkeitserfassungsmittel und Zuführen eines Geschwindigkeitserfassungssignals an die Berechnungseinheit,
• – Berechnen eines zu der erfassten Längsschwingung sich gegenphasig verhaltenden Motordrehmoments oder Bremsmoments als Gegenphasenmoment in Abhängigkeit von der erfassten Längsschwingung und Fahrzeuggeschwindigkeit in der Berechnungseinheit,
• – Zuführen eines dem Gegenphasenmoment entsprechenden Gegenphasensteuersignals an eine Beeinflussungseinheit und
• – Beeinflussen eines aktuellen Motordrehmoments oder des Bremsmoments eines Motor- und/oder Bremssystems des Fahrzeugs durch die Beeinflussungseinheit in Abhängigkeit vom Gegenphasenmoment derart, dass die Längsschwingung gedämpft wird.

The object mentioned is therefore achieved, according to the features of the main claim, firstly by a method for damping longitudinal vibrations of liquids in vehicle transport containers or vehicle induced acceleration induced thereby, the method comprising the following method steps:

• Detecting longitudinal vibrations of the liquid or of the vehicle by a vibration detection means and supplying a vibration detection signal to a calculation unit,
• Detecting the vehicle speed by a speed detection means and supplying a speed detection signal to the calculation unit,
• Calculating an engine torque or braking torque that acts in antiphase relative to the detected longitudinal vibration as a counter-phase torque as a function of the detected longitudinal vibration and vehicle speed in the calculation unit,
• - Applying a counter-phase torque corresponding to the antiphase control signal to an influencing unit and
• - Influencing a current engine torque or the braking torque of an engine and / or braking system of the vehicle by the influencing unit in response to the antiphase torque such that the longitudinal vibration is damped.

With Help of electronically controlled engine and / or brake systems and these associated sensors can detect these vibrations and be dampened by an antiphase, restrained moment. The engine and / or braking system is a vehicle propulsion engine and a brake, preferably a non-wearing permanent service brake.

There it is at the vibrations generated by the movement of the liquid in the vehicle is low-frequency harmonic oscillations, can these by appropriate algorithms in a related control device be recognized very well.

The Frequency of such vibrations is mainly dependent on the viscosity of the transported Liquid. By existing in new vehicles CAN bus network, ie an in-vehicle electronic communication system, can be a corresponding functionality is not only in the engine control unit, but also implement in other control and / or regulating devices (e.g., transmission control or brake control).

By a targeted damping of the excited by the liquid movement vehicle Schwin Not only the driving safety and comfort can be improved, but it can also reduce foaming of the liquid in the transport tank or completely avoided.

Preferably is the current engine torque during fluid-induced acceleration of Vehicle reduced and the liquid condition Delay increased again to a driver's desired torque. This affects the engine torque in terms of vehicle longitudinal acceleration not additive but antiphase to the fluid movement caused longitudinal vehicle acceleration, causing a longitudinal vibration the liquid in the transport container quickly and reliable muted which is natural at the same time the disturbing Vehicle longitudinal vibration eliminated.

According to one Another variant is the engine and / or braking system of the vehicle at the liquid condition longitudinal acceleration the vehicle an additional Braking torque switched on. This process is understood to mean that that of the driver and / or an engine control unit for a current driving situation provided engine torque is reduced by a braking torque amount will be to the desired damping effect to achieve. For this purpose, for example, the already mentioned wear-free continuous service brake (Retarder) operated in antiphase become. The strenght a related matter Braking intervention, whether on the engine by an engine braking effect or through a retarder, based on the height of the longitudinal acceleration of the vehicle or the liquid in the transport tank. For example, in a liquid-related delay the currently requested by the driver and / or the engine control unit Motor torque for damping the oscillation in opposite phase by such a calculated amount elevated.

According to one In another aspect, the invention also relates to a device for damping of longitudinal vibrations of liquids in vehicle transport containers and / or induced by these vehicle longitudinal vibrations. This device essentially comprises a vibration detecting means for detecting of longitudinal vibrations the liquid or the vehicle, a speed detection means for detecting the vehicle speed, a calculation unit for calculating one to the detected longitudinal vibration antiphase behaving engine torque or braking torque as Antiphase torque in dependence from the detected longitudinal vibration and vehicle speed, and for generating the antiphase torque corresponding antiphase control signal for an influencing unit, which is designed such that this is a current engine torque or braking torque depending influenced by the antiphase torque so that the longitudinal vibration is damped.

through Such a device are fluid-induced longitudinal vibrations For example, a tanker quickly and reliably damped. This increases on the one hand, the driving safety of the vehicle and also the driver an improved ride comfort provided.

Preferably the influencing unit is designed such that it the current engine torque at a fluid-related acceleration the vehicle reduced and with a liquid-related delay of Vehicle again increased to a driver's desired torque.

With Help of electronically controlled engine and / or brake systems or related control and / or control devices can these fluid-related Vibrations of the vehicle easily detected and by an antiphase subdued moment become.

Preferably the influencing unit is designed such that it Engine and / or braking system during the fluid-induced acceleration the vehicle an additional braking torque aufschaltet. This happens, for example, by activating a Engine brake or by a service brake. Also a combination of these Both devices may be useful.

According to one Another embodiment of the invention is the influencing unit as a wear-free Continuous service brake formed. This can be used as a so-called primary retarder or as a secondary retarder be educated.

To In another variant, the influencing unit is designed such that that this is the engine torque at the liquid delay of the Vehicle over increase the current engine torque can.

The Frequency of liquid-induced vehicle longitudinal vibration is as already mentioned mainly dependent on the viscosity the transported liquid. By existing in new vehicle types CAN bus composite can be a corresponding device-related function not only in the engine control unit, but also in other control and / or regulating devices in the vehicle, as in the transmission or brake control device, realize.

Preferably, a speed detecting means serves as a vibration detecting means. al Alternatively or in addition thereto, further sensor means, such as acceleration sensors, which are designed to detect longitudinal vibrations of liquids can be used.

The Invention leaves itself with reference to an embodiment further explain. For this purpose, the description is accompanied by a drawing. In this shows

1 a simplified schematic structure of a system for damping longitudinal vibrations of a vehicle, which are generated by a liquid in a transport container of a vehicle, and

2 a diagram in which the time course of a liquid-induced vibration of the vehicle speed and an antiphase oscillating engine torque are shown.

1 shows a simplified schematic structure of a system for damping longitudinal vibrations of a vehicle, which is generated by a liquid in a transport container of a vehicle.

This system initially comprises a vibration detection means 10 for detecting longitudinal vibrations of a liquid in a vehicle transport container 12 a vehicle, such as a tanker truck.

In addition, this system includes a speed detection means 14 for detecting the current vehicle speed V and a calculation unit 16 for calculating an engine torque M which is in antiphase relative to the detected longitudinal vibration as a counter-phase torque as a function of the detected longitudinal vibration and vehicle speed, and for generating an antiphase control signal which corresponds to an antiphase torque and which is an influencing unit 18 can be supplied.

The calculation unit 16 is via electrical lines with the vibration detection means 10 , the speed detecting means 14 and the influencing unit 18 electrically connected. The influencing unit 18 is designed such that this is a current torque of an engine and / or brake system 20 depending on the antiphase torque so influenced that the longitudinal vibration of the vehicle or the liquid in the tank 12 is dampened. The engine and brake system 20 includes a vehicle drive motor and optionally a braking device acting on the vehicle. This braking device is preferably a wear-free continuous service brake, so for example a retarder

2 shows a diagram in which the time course of a caused by a liquid-induced vibration in a vehicle transport tank ne ne of the actual vehicle speed V or change the vehicle speed against a per se desired vehicle speed G and an antiphase oscillating motor torque M are shown.

This Motor torque M is here with reference to a dashed line simplified only with the time course of that amount of change shown, due to the vibration damping control according to the invention is deducted from that engine torque, which is an engine control unit due the performance requirement by the driver and other driving conditions for the current date has provided.

The desired by the driver Vehicle speed G becomes constant in the present example accepted. The fluid movement-related change V of this vehicle speed G on the other hand has a sinusoidal course, the acceleration phases B and delay phases A has.

Until a time t ₀ no damping measures are taken to influence the fluid-induced change V in the vehicle speed G. From the time t ₀ , however, an inventive damping of the longitudinal vibration of the liquid is performed. It is through the engine and brake system 20 a through the calculation unit 16 (please refer 1 ) calculated and set engine torque M or braking torque generated, the course of which is out of phase with the course of the change V of the measured vehicle speed G.

The motor torque set in this example therefore corresponds to a reduction of or equal to that engine torque that is conventionally set by the engine control unit due to the current driving situation and the current power demand by the driver. Due to the shifted by 180 ° course between the liquid-induced change V of the vehicle speed G and the set engine torque M, the amplitude of the longitudinal vibration of the liquid and thus the vibration in the longitudinal axis of the vehicle is attenuated, as in the diagram within the damping periods t ₁ and t _{2 is} clearly visible.

This damping is continued until at the end of the period t ₂ this oscillation as completely eliminated. For this purpose, therefore, the engine torque M is reduced during acceleration of the vehicle, while decelerating the vehicle, the engine torque is increased again to the driver's desired torque. Thus, the engine torque does not additive but antiphase and thus dampening the caused by the liquid vehicle longitudinal vibration.

With Help of the device and the method according to the invention can be in combination with known devices for fluid calming in a liquid tank a tanker vehicle significantly better damping values than conventional achieve. In addition, the invention allows, partially or completely, at least on technically complex damping devices in such a liquid tank to renounce. As such, all components for a device according to the invention already present in modern tank vehicles, reduced the realization of such an advantageous damping system almost completely on the implementation of related software, for example in a related matter Vehicle control unit.

10

Vibration detecting means

12

Vehicle transport containers

14

Speed detecting means

16

calculation unit

18

influencing unit

20

Engine- and / or braking system

A

deceleration phase

B

acceleration phase

G

vehicle speed

M

amount of change the engine torque; braking torque

V

modification the vehicle speed,

actual vehicle speed

t ₀

time Beginning of the damping measure

t ₁

first Damping period

t ₂

second Damping period

Claims (10)

Method for damping longitudinal vibrations of liquids in vehicle transport containers ( 12 ) and / or of vehicle-induced oscillations induced thereby, characterized by the steps: - detecting the vehicle speed (V) by a speed detecting means ( 14 ) and supplying a speed detection signal to the calculation unit ( 16 ) and / or detecting longitudinal vibrations of the liquid or the vehicle by a vibration detection means ( 10 ) and supplying a vibration detection signal to a calculation unit ( 16 ), - Calculating an antiphase relative to the detected longitudinal vibration engine torque (M) or braking torque as a counter-phase torque as a function of the detected longitudinal vibration and vehicle speed in the calculation unit ( 16 ), - supplying a counter phase control signal corresponding to the antiphase torque to an influencing unit ( 18 ) and - influencing a current engine torque or a braking torque of an engine and / or brake system ( 20 ) of the vehicle by the influencing unit ( 18 ) in response to the antiphase torque such that the longitudinal vibration is damped. Method according to claim 1, characterized in that that the current engine torque during liquid-induced acceleration (B) of the vehicle is reduced and during liquid-induced deceleration (A) is increased again to a driver's desired torque. Method according to claim 1, characterized in that that the engine torque (M) at a deceleration (A) of the vehicle on the current engine torque increased becomes. Method according to one of claims 1 or 2, characterized in that the engine and / or braking system ( 20 ) of the vehicle at the fluid-related acceleration (B) an additional braking torque is switched on. Device for damping longitudinal vibrations of liquids in vehicle transport containers ( 12 ) and / or vehicle induced oscillations induced thereby, characterized by a speed detection means ( 14 ) for detecting the vehicle speed (G) and / or a vibration detection means ( 10 ) for detecting longitudinal vibrations of the liquid or of the vehicle, a calculation unit ( 16 ) for calculating an antiphase motor torque (M) or braking torque as antiphase torque as a function of the detected longitudinal vibration and vehicle speed (G), and for generating an antiphase torque corresponding antiphase torque signal for an influencing unit ( 18 ), which is designed such that it influences a current motor torque or braking torque in dependence on the antiphase torque in such a way that the longitudinal vibration is damped. Apparatus according to claim 5, characterized in that the influencing unit ( 18 ) Is designed such that these the current engine torque at an acceleration (B) of the driving reduce and at a deceleration (A) can increase again to a driver's desired torque. Device according to one of claims 5 or 6, characterized in that the influencing unit ( 18 ) is designed such that this the engine and / or braking system ( 20 ) of the vehicle at the acceleration (B) can apply an additional braking torque. Device according to claim 7, characterized in that the engine and / or brake system ( 20 ) has a wear-resistant continuous service brake. Device according to one of claims 5 to 8, characterized in that the influencing unit ( 18 ) is configured such that it can increase the engine torque at the deceleration (B) of the vehicle over the current engine torque. Device according to one of claims 5 to 9, characterized in that the vibration detection means ( 10 ) is designed as a pressure sensor or as an acceleration sensor.