SE537144C2 - Estimation of an inertia for a condition in a vehicle - Google Patents

Abstract

537 144 Summary A procedure and a system for estimating a fidelity / for a condition in a vehicle are presented, wherein the vehicle comprises at least one regulator arranged to regulate at least one actual state value Sacr against at least one respective corresponding reference value S „f. According to the present invention, the system comprises: a determining unit arranged to determine at least one actual capture sequence Strans actfor said at least one actual state value Sact against said at least one respective corresponding reference value Sref; a comparison unit arranged to perform at least one comparison of the at least one actual capture sequence Strans act with at least one respective corresponding related capture sequence Strans_exp; and an estimating unit arranged to estimate said inertia / based on said at least one comparison.

Description

Technical invention The present invention relates to a method for estimating an inertia / for a condition in a system according to the preamble of claim 1. The present invention also relates to an estimation system arranged for estimating an inertia / for a state in a system according to the preamble of claim 38, and a computer program and a computer program product, which implement the method according to the invention.

Background The following background description is a description of the background to the present invention, which does not have to be prior art.

Control systems comprising one or more controllers are currently used for controlling a large number of different types of systems, for example in a vehicle. The control often includes that a state is controlled against a reference value for the state.

Many of the systems to be controlled by such control systems have an inertia /, such as a mass inertia, a thermal inertia K or a moment of inertia J. By inertia is meant and in this document a resistance to change, for example to a change in motion or to a change in temperature , which means that changes do not take place momentarily, that is to say that the change takes place over a period of time.

A cruise control system Or an example of a vehicle system comprising an inertia / related to a vehicle mass in, in which one or more regulators are used to regulate an actual speed vaa for the vehicle. An engine system is another example of a system with a fidelity / related to a torque moment J for the engine in the vehicle, in which one or more regulators are used to regulate an actual speed waa for the engine.

Another example Or a temperature control system with a thermal inertia K, where an actual temperature Tact for a limited volume is regulated by using one or more controllers. Another example is a system for acceleration limitation for a vehicle with an inertia I related to a vehicle mass m, through which an actual acceleration clact for vehicles is regulated by the one or more regulators. In a system for braking a vehicle with an inertia I related to the vehicle mass m, the actual speed vact for the vehicle is regulated by the one or more regulators.

Another system Or a system for PTO at the Open driveline in a vehicle, where the engine speed of an engine in the vehicle is regulated, but where the inertia I is also related6 to equipment connected to the PTO in the vehicle. Such equipment may, for example, include pumps, cranes or other equipment operated via the vehicle's power take-off.

Control systems use, and are therefore dependent on access to, a number of parameters to be able to control various functions in a correct and efficient way. Examples of such parameters, on which the control systems base their control functions, include the vehicle mass iii, the moment of inertia J of the engine, the thermal inertia K of a limited volume and a total moment of inertia _hot for engine and power take-off.

In this document, the background and invention will be described to a relatively large extent as being implemented in a vehicle. However, the present invention is generally applicable to substantially all systems in which a state of inertia is to be regulated to a reference value, as will be appreciated by one skilled in the art.

A weight in has a system, such as a vehicle weight, where the vehicle can be constituted by a vehicle day, constitutes an important parameter in many functions in a vehicle's control system. The weight of the vehicle affects the vehicle considerably in many situations, which is why it is very important to be able to correctly estimate this weight. The weight of the vehicle typically varies in models of the vehicle, which are used for various coatings and controls in the vehicle.

For a vehicle which can transport large loads, such as buses, which can transport a starting number of people, or trucks, which can transport different types of loads with large weights, the weight can vary considerably. For example, an unladen truck weighs considerably less than the same truck when it is maximally loaded. An empty bus also has considerably less mass than the same bus when it is full of passengers. For a passenger car, for example, the variations for the mass are smaller than for vehicles intended to transport large loads, but even here the difference between an empty and a fully loaded passenger car, where the fully loaded passenger car can also include a coupled and loaded slap, can be relatively large in relation to the legal weight of the car.

The mass of the vehicle affects a driving resistance for the vehicle, which makes the weight of the vehicle an important parameter, for example for automatic gear selection. Automatic gear selection is done, for example, in an automatic geared manual gearbox, for which it is important to be able to determine a current gear resistance and thus which gear to select in a current case. The moment of inertia J for the motor is also an important parameter in shaft selection. 3 537 144 How a topography for a road section affects the vehicle also strongly depends on the weight of the vehicle, the viii saga of the vehicle's mass, since the weight is decisive for how much the vehicle is accelerated or decelerated by a downhill or uphill slope. The weight of the vehicle is therefore an important parameter even in speedometers which take into account the topography of a road section, called Look-Ahead speed bumpers, where the size of a desired engine torque at one time depends on how the next section of road section topography will affect the vehicle speed. Of course, the weight of the vehicle and the moment of inertia J for the engine are important parameters even at conventional speed.

The thermal inertia K is an important parameter regarding essentially all types of temperature control, which affect, for example, driver and passenger comfort, as well as safety in a vehicle. Bide drivers of a vehicle and passengers, for example in a bus, should avoid large and sharp and unrestrained temperature variations. In addition, in terms of safety, it is important that one of the driver's Desired cab temperature hills, in which, for example, high temperature can affect a fatigue has the driver. For cold rooms, for example in vehicles where the cargo is to be stored and / or transported at a certain temperature, for example food transports, the thermal inertia K is also determined to obtain a correct estimate so that an accurate temperature control can be provided.

For vehicles where a power take-off can be provided, it is important that the equipment connected to the power take-off in the vehicle can be driven by the power take-off, the viii saying that an engine in the vehicle can maintain a substantially constant speed during the power take-off. BRIEF DESCRIPTION OF THE INVENTION Hereinafter, previous solutions and problems with these will be described primarily for estimating vehicle weight. The person skilled in the art realizes that similar problems exist for previous estimates of mass for systems other than vehicles, as well as for the moment of inertia J for the engine, for the thermal inertia K and for the total moment of inertia Jtot required to drive equipment connected to the power take-off. all the inertia / which are estimated by the present invention.

There are today several methods which are applied to estimate the vehicle mass iii, that is to say the weight of the vehicle. Such a method uses information from an air suspension system in the vehicle. The air suspension system applies axle pressure to all axles that have air suspension, and reports this load to a control unit, which based on these loads can calculate the mass of the vehicle. This method works well if all axles are air-sprung. However, the method works unsatisfactorily, or not at all, if one or more axles lack air suspension. This method is, for example, particularly problematic in vehicle roofs including slaps or trailers, which do not report axle load. This can occur relatively often as more or less unknown slips are often connected to the vehicle roof when using the vehicle. This method is also problematic during operation of the vehicle, as the axle pressures vary as the vehicle crosses irregularities in the roadway, which can lead to the weight estimate being incorrect due to the varying axle pressures.

Other known methods for mass estimation consist of acceleration-based mass estimates. These use the fact that one can shave the mass from a force the engine supplies to the vehicle and an acceleration this force results in. The force from 537 144 the engine is known in the vehicle, but for these methods the acceleration needs to be measured or estimated.

According to one method, the acceleration is estimated by performing a derivation of the vehicle speed. This method works well at high accelerations, it viii saga on low gears at relatively low speeds, but it is a disadvantage of the method that it is affected by the wind glut, which is necessary for the derivation, since the water glut is an unknown parameter for the system.

According to another method, the acceleration is estimated using an accelerometer. The accelerometer-based method has the advantage that the acceleration is fed directly. However, only a limited number of today's vehicles include an accelerometer, which means that this method is not generally applicable to all vehicles.

The current accelerometer-based method also suffers from the noise meter signal being noisy, which reduces the accuracy of the method.

According to another method, the acceleration is estimated during rotation. This method uses the assumption that the choke resistance is unchanged during a shift and therefore for the vehicle's acceleration before and after shifting to determine the weight of the vehicle. This method results in very unsatisfactory estimates of the vehicle mass.

The acceleration-based mass estimates generally have disadvantages in that certain chore conditions must be met in order for a good estimate to be performed. It is not at all certain that these preconditions will be met during a harvest, so a good mass estimate is then not possible. For example, the acceleration-based mass estimates require a full throttle acceleration on low gears to give a reliable result. Since such a full throttle acceleration does not always occur during a corn, as in the vehicle the corn starts on a downhill slope, for example from a petrol station at a junction to a motorway, and then with the help of the downhill slope can accelerate relatively calmly and then keep essentially a constant speed during the rest of the ride, these methods often do not give a good estimate of the vehicle weight.

Thus, the prior art methods for mass estimation are not always possible to apply and / or do not provide reliable estimates for all grains.

Even known solutions for estimating the thermal inertia K and of the total moment of inertia J0 related to power take-off are deficient. The total moment of inertia _hot for power take-off typical unknown, since equipment of varying type can be connected to this power take-off, where the vehicle can not detect or be prepared for all this unknown equipment of different type. These give substandard estimates and / or estimates which require an initial addition in the complexity of the vehicle.

It is an object of the present invention to provide a method and a system for estimating inertia which solves the above-mentioned problems with prior art estimates.

This object is achieved by the above-mentioned method according to the jug-drawing part of claim 1. The object is also achieved by the above-mentioned system according to the j-drawing part of claim 38, and by the above-mentioned computer program and computer program product.

The present invention utilizes an analysis of an actual capture process Strans actfor at least one actual state value Sact against at least one respective corresponding reference value Sw to estimate an inertia / for a state in a system. By comparing the appearance, this gets at least an actual capture process S trans _act with at least one respective corresponding expected capture process Strans_expl Which has an appearance that presupposes correct estimates of the condition, can thus according to the present invention the inertia / for the condition be estimated.

This gives a very accurate estimate of the condition, which Oven Or robust because the systems on which the estimate is based Or choices defined. The estimation can be implemented with a very small addition in cost and complexity for the system.

According to one embodiment, the fidelity estimation according to the present invention can be used to estimate a mass related to the system, such as for example a vehicle mass. As a result, reliable estimates of the mass are obtained, for example, of the vehicle mass in a vehicle, which will be able to be utilized by a large number of systems and functions in the vehicle, such as, for example, speed control and gear selection. As a result, the fuel consumption of the vehicle can be reduced and / or the performance improved by the vehicle Okas, as choices based and choice-based choices can be made in these systems, which in total can reduce the fuel consumption and / or increase the performance.

According to one embodiment, the fidelity estimate according to the present invention can be used to estimate an engine's moment of fidelity J, whereby for example the fuel consumption of a vehicle can be reduced and / or the performance of the vehicle can be increased, since substantiated and elective choices can be made in these systems. . According to one embodiment, the inertial estimation according to the present invention can be used to estimate thermal inertia K for defined volumes, whereby temperature control of, for example, an office space, a cold room, a cab or a cargo space can be regulated very precisely based on the knowledge of the thermal inertia K. Increased comfort for office staff and drivers as well as things such as transport of food, for example, can be made safe.

According to one embodiment, the inertial estimation of the present invention can be used to estimate the total moment of inertia threat at a power take-off. According to the present invention, the total moment of inertia [tot which includes both the moment of inertia J of the engine and the moment of inertia of the PTO I PTO Lot = I + JPTO • Hereby an estimate of the total moment of inertia J tOt is obtained which can be used to regulate the engine speed constant force to drive the equipment connected to the power take-off can be provided, since this regulation is facilitated by a knowledge of the total moment of inertia itot • Thus, with the present invention more or less okOnd equipment of varying type can be driven via a permanent well-dimensioned power take-off in the vehicle, which previously has been very black. The controller can also automatically calibrate itself against a better estimate of the total moment of inertia in the Jtot, so that it is always in-Land due to controller aggressiveness.

According to an embodiment, the present invention can be used for systems where a control of the system Or is based on a model which comprises a force equation or another equation which Or is related to the system to be regulated. Thus, the control of the state cid emanates from the systems which include 9,537,144 and the respective state. In other words, the systems are regulated based on the systems themselves, since the regulation of the systems is performed based on models of the systems to be regulated. As a result, there is a good knowledge of the systems that are to be regulated according to the control algorithm, which makes the estimation robust.

According to an embodiment, the present invention can also be used for systems in which a control of the system is performed by a PID controller or by a differential PI controller. The fidelity estimate according to the present invention can therefore be applied in that a large number of different control systems are used to control systems in vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further elucidated below with reference to the accompanying drawings, in which like reference numerals are used for like parts, and are used: Figure 1 shows a flow chart of a method according to the invention, Figure 2 shows an example shows an example of a trapping process against a reference value, Figures 4a and 4b show an example of mass determination of a vehicle, and Figure 5 shows a control unit.

DESCRIPTION OF PREFERRED EMBODIMENTS The present invention relates to an aspect of a method for estimating an inertia of a state in a system. The state, for which according to the present invention a fidelity / can be estimated, has a resistance to change in the state, for example a resistance to a change in motion or to a change in temperature. Changes to the condition therefore occur over a period of time and probably not momentarily.

The present invention provides that at least one controller is arranged to control at least one actual state value Sact in the system against at least one respective corresponding reference value Sref.

Figure 1 shows a flow chart of a method according to the present invention.

In a first step 101 of the procedure, at least one actual subtraction process is determined for the At least one actual state value Sact against the At least one respective corresponding reference value Sref. If at least one actual state value Sact is regulated against it At least one respective corresponding reference value Sref arises at least one actual capture process Strans act this is at least an actual input process Strans act describes how the at least one actual state value Sact at least affects the respective sip and svd corresponding to the reference value Sref. The appearance of this, at least an actual process of incarnation, is due in part to the fidelity / condition.

In a second step 102 of the procedure, at least one comparison of the at least one actual capture process Sans act is performed with at least one respective corresponding expected capture process Strans_exp • This expected capture process Strans_exp has an appearance which 11 537 144 would have been the result of the actual process. had access to a correct value for inertia I. If, for example, inertia I Or related to the vehicle mass m and am the control system has access to a correct estimate of the vehicle mass, then the actual capture process Strans actvara will be identical to the expected capture process Strans_exp • PA correspondingly corresponds appearance, the expected trapping process Strans_exp has an actual trapping process Strans act based on correct estimates of the moment of inertia J, the thermal inertia K, or the total moment of inertia [Jtot at a power take-off.

However, sip distinguishes the actual capture process Strans actofta from the corresponding expected capture process Strans_exp because completely correct estimates are available, which are utilized by the present invention.

In a third step 103 of the method, the inertia I is estimated based on the at least one comparison of the at least one actual capture process Strans act with the at least one corresponding expected capture process Strans_exp • Thus, according to the present invention, the capture process Sans act is used for at least one actual state value. a respective corresponding reference value Sref to determine the fidelity I has state. As a result, a very reliable estimate of, for example, the mass rn, the moment of inertia of the engine J, or the thermal inertia K of, for example, the driver's cab can be obtained. 12 537 144 Many systems have built-in inertia for their state. Essentially all such efficiencies can be estimated by utilizing the present invention. A couple of embodiments of the present invention will be described below. However, one skilled in the art will recognize that the present invention can generally be applied to substantially all systems where the state of the systems has some kind of reluctance to burn, that is to say some kind of fidelity.

The control of the at least one state in the system to be regulated by the controller is model-based according to an embodiment of the invention. The model which has been applied is related to the system to be regulated in that the model includes a force equation or another equation that is related to this system and it includes at least an actual state value Sact. Thus, a model of the system is developed at least by having a force equation or other equation set up for at least a part of the system.

Furthermore, in controlling the system, the control of the state is performed by utilizing a control signal, the model-based control causing a magnitude of this control signal to be proportional to a change before the at least one state, that is to say against a change of the at least the actual state value Sact . Thus, a control unit provides the control signal based on the model so that its magnitude is proportional to a change in the state.

With such a control system, it can be implemented in a temperature control system, for example an actual temperature Tact is controlled against a temperature reference value Tref. In an engine control system in a vehicle, an actual speed waa can be controlled against a reference speed wref. In a cruise control system in a vehicle, an actual vehicle speed may be controlled at a reference speed. In a control system for acceleration limitation, an actual acceleration aaa can be controlled against a reference acceleration a „f. In a braking system of a vehicle, an actual speed may be controlled towards a reference value in the form of a maximum speed vm „. Embodiments of the invention in which these guides are used to determine inertia will be described in more detail below.

According to an embodiment of the invention, the system to be regulated is a cruise control system, for example in a vehicle, which has an inertia / as Or related to a mass in related to the system, for example a mass for the vehicle. The model on which the regulation Or is based takes into account a difference between an actual acceleration aaa related to the system and a reference acceleration a „f for the vehicle, where the difference depends on a time parameter T.

The actual state value Saa to be controlled by the regulator is an actual speed vaa related to the system, for example an actual vehicle speed, that is to say the actual speed the vehicle will keep as a result of the cruise control. The reference value Sref against which the state is controlled has a reference speed v „f for the system. Since mass in related to the system has is related to the inertia / according to this embodiment the mass m can be estimated reliably by analyzing the capture process Strans actfor the actual state value Saa against the corresponding reference value Sre f • There are many different types of cruise control for vehicles. In some of these cruise control the driver himself sets the reference speed v „f. In other types of cruise control, the driver sets a set speed vsa based on which the cruise control then determines the magnitude of the reference speed v „f sent to the speed controller, whereby the reference speed Vref may have a different value than the set speed vsa.

The model takes into account a difference between an actual acceleration a 't related to the system, for example an actual vehicle acceleration, the viii saga the actual acceleration resulting from the cruise control, and a reference acceleration are f for the system. This difference is due to a time parameter which is described in more detail below. The time parameter T determines how the appearance of the capture process Strans actfor the actual speed va against the reference speed vref looks like in such a way that a smaller value of the time parameter T per a fast capture process and a larger value of the time parameter T per a slow capture process.

This is shown schematically in Figure 2 for a vehicle example, where the dashed straight horizontal line Or a reference velocity is against which actual velocities for different values of turn. As illustrated in Figure 2, the smallest value of the time parameter T = 2 (solid curve) the fastest capture process Sans act'det larger value of the time parameter T = (dotted curve) a slower capture process Stransact / and the largest value of time pair 8 dashed curve) the slowest trapping process Strans act • According to an embodiment of the present invention, the value of the time parameter T is related to a chore mode, also called carriage, for example a vehicle. This is shown schematically in Figure 3, where the dashed straight horizontal line Or a 537 144 reference velocity v „v against which actual velocities for different values of T oscillate. The value of the time parameter T is seen as related to an aggressiveness has the regulation. Therefore, in a normal chore mode, for example referred to as "standard" (dotted curve), the time parameter T can be given a medium value.

For a more aggressive chore mode, for example called "power" (dashed curve), the time parameter T is given a relatively small value am the actual speed vaa is lower than the reference speed v „f. For this cormod, the time parameter T is given a relative start if the actual velocity vaa is higher than the reference velocity v „f, as shown in Figure 3. The more aggressive cormod power thus swings in quickly as it approaches the reference velocity from below (from a lower speed), but swings in slowly as it approaches the reference speed vref from above (from a higher speed).

The cormod power thus quickly tries to reach the reference speed from below and feeds early from the top, which gives a powerful impression, a higher average speed and a time gain compared to the other cormods.

For a less aggressive chore mode, for example called "eco" (solid curve), the time parameter T is given a relative start where the actual speed vaa is lower than the reference speed v „f. Correspondingly, the time parameter T for this chore mode is given a relatively small value of the actual speed vaa is higher than the reference speed v „f, as shown in Figure 3. The less aggressive chore mode eco thus swings in quickly when it approaches the reference speed v„ f from above (from a higher speed), but swings in slowly as it approaches the reference speed from below (from a lower speed), which gives a soft impression, as well as a lower average speed and thus a lower total fuel consumption. In addition, the amount of decelerated energy is also reduced by the co-mode eco of a vehicle, since the vehicle, for example, has a lower speed at the top of the crown during a section of the road comprising an uphill slope followed by a downhill slope. Due to the lower speed at the top, less braking is required under the downhill slope, with less energy being braked away.

In connection with Figures 2 and 3, it has been described above how the time parameter T affects the capture process Strans actfor the actual state value Saa, has the actual speed vaa, against the corresponding reference value Sreff, has the reference speed vref, for a cruise control system.

The time parameter T has a corresponding effect on the capture process Sans act for the engine systems, temperature control systems, acceleration limitation systems, brake systems and PTO systems described below.

According to one embodiment, where the invention is applied in cruise control, the model related to the system to be regulated comprises a force equation with an appearance according to: Fic + i = m * (vref -Vact aaa) + Fk, dar (eq. 1) Fk + 1 is a force which will act on the said vehicle at the next iteration of the equation is calculated; - m is the mass of the vehicle; vref is the reference speed; Guard is the actual speed; T is the time parameter; clact is the actual acceleration of the vehicle; and - F1, is a current force which acts on the vehicle. According to an embodiment of the invention, the estimation of the mass m may constitute an estimate of a mass of an elevator, the viii saga of a weight for an elevator, where the system is an elevator system which has an inertia I related to a mass m of the elevator. As a result, a correct estimate of the total mass of the lift can be obtained.

The actual state value Sact to be controlled by the controller is an actual speed vact for the elevator. The reference value Sref against which the condition is controlled has a reference speed vref for the elevator. Since the mass in front of the lift is related to the inertia / can according to this embodiment mass m has been estimated reliably by analyzing the trapping process Strans actfor the actual until the tooth value Sact against the corresponding reference value Sref. The model on which the control is based takes into account a difference between an actual acceleration aect for the lift and a reference acceleration aref for the lift, since the difference depends on a time parameter T.

Those skilled in the art will appreciate that many of these other systems may be appreciated accordingly. For example, the mass of cargo on substantially all types of conveyor belts, such as luggage conveyor belts, tray belts for dining rooms, conveyor belts in the manufacturing industry and the like, can be estimated by utilizing the present invention. This is because the load on the conveyor belt, such as sinks, counters, vehicles under construction, etc., affects the conveyor belt's inertia I. Therefore, the masses can be easily estimated based on analysis of the capture process Strans_act for the actual state value Sact against the corresponding reference value Sref, which can be velocities.

If the masses have these systems change, as will be the case with, for example, the vehicle mass of others when reloading, if more sinks are placed on a luggage strap, or if many disks are placed on a wash strap, this model-based controller will also calibrate itself according to the new masses.

According to an embodiment of the present invention, the system to be controlled by the controller is an engine system, for example in a vehicle, where the model of the engine system takes into account a difference between a change w -Cza of an actual engine speed and a change m -Tlef of a reference speed for the motor, where the difference depends on the time parameter T. The actual state value S „t to be controlled has an actual speed waa for the motor and the corresponding reference value S„ ef is a reference speed coref for the motor. The inertia I is based on a moment of inertia j of the engine, so this moment of inertia J can be estimated based on the comparison of the actual capture process Stransact with the expected capture process Strans_exp • According to an embodiment of the present invention, the system to be controlled by the controller is an acceleration limiting system a vehicle, where the model of the acceleration limitation system takes into account a difference between the actual acceleration acia and the reference acceleration aref. The actual state value Saa to be controlled then gives an actual acceleration aaa related to the system and the reference value S „ef used in the control gives a reference acceleration are! related to the system, for example a reference acceleration a „f for the vehicle.

The inertia I in the acceleration limitation system is based on a mass m related to the system, for example the vehicle mass iii, which means that the mass m can be estimated based on the comparison of the actual capture process Strans act with the expected capture process Strans_exp • 19 537 144 The physical model, on which the regulation is based on includes the force equation which has an appearance according to: Fk + 1 = M. * (aref - ct ,,, t) + Fk, ddr (eq. 2) Fk + 1 is the force that will be related to the system at ndsta iteration; m is the mass related to the system; ref is the reference acceleration; aaa is the actual acceleration; and Free, is a previous current force which acts on the vehicle.

Thus, the actual acceleration aaa is controlled against reference acceleration aref so that a limitation of the actual acceleration aaa is obtained, which gives a capture process Strans_exp which can be used to determine the mass m, for example a vehicle mass am the system relates to a vehicle.

As described above, the size of the time parameter T determines how the capture process Strans_exp looks when the actual acceleration aaa approaches reference acceleration aref, so that different values of the time parameter T give different behaviors for the acceleration limitation system.

According to an embodiment of the present invention, the system to be regulated constitutes a system for braking, for example, of a vehicle. Essentially any type of vehicle braking system can be controlled according to this embodiment, for example a service brake, a retarder, or an electromagnetic brake, which can be constituted, for example, by an electric motor in a hybrid vehicle. The actual state value S "t constitutes has an actual speed vaa and the reference value Sraf constitutes a maximum speed vmax, the value of which, for example, for a vehicle can be based on a speed limit for a road section. 537 144 The inertia of the braking system is based on the mass m related to the braking system, for example to a vehicle mass, which means that the mass m, for example the vehicle mass, can be estimated here based on the comparison of the actual Stransact induction process with the expected Strans exp indentation process.

For this embodiment of the invention, the model of the braking system takes into account a difference between the actual acceleration aaa and the reference acceleration are /. for vehicles dl the force equation has an appearance according to: Bk ± i m * (vmax _vaat aaCT) + Bk, ddr (eq. 3) Bk + 1 is a force which will be related to the system at the next iteration of the algorithm; m is the mass; Vref dr reference speed; Vact Or the actual speed; T is the time parameter; (tact Or the actual vehicle acceleration; and Bk Or the current braking force related to the system.

As can be seen from Equation 4, the difference between the actual vehicle acceleration aaa and the reference acceleration aref depends on the time parameter T since the reference acceleration aref 14120.0c -vact corresponds to the term. in the same way as described above, the magnitude of the time parameter T determines how the induction process Strans_exp looks when the actual velocity is at the maximum velocity vmax.

According to an embodiment of the present invention, the system to be regulated constitutes an engine, for example in a vehicle.

The actual state value Sact which is to be controlled by this control then constitutes an actual speed waa for the engine and the reference value Sref against which the actual speed waa is to be controlled constitutes a reference speed co „f far the engine. The inertia of the engine system is based on a moment of inertia J for the engine, which means that the moment of inertia J of the engine can be estimated based on the comparison of the actual capture process Stransact With the corresponding expected capture process Strans_exp • The model gets the engine system, on which the regulation is based. between a change w - c; take of an actual speed fbr the engine and a change w -; ef of a reference speed for the engine. The difference depends here on a wref -waa time parameter T, since the term includes the time parameter T, so that the course of the actual speed coact winding Strans act against the reference speed coref can be controlled by the magnitude of the time parameter T, in the same way as described above for the other embodiments.

According to the embodiment, the power equation of the model has an appearance according to: Tk + 1 = I * ref -Wact ct) + Tk, dar (eq. 4) - Tk + 1 Or a torque which will be emitted by the motor at the next iteration of the algorithm; J Or the moment of inertia father the engine; wref Or the reference speed of the motor; waa Or the actual engine speed; - r Or the time parameter; waa Or a change in the actual speed; and Tic Or the torque currently emitted by the engine. According to an embodiment of the present invention, the system to be controlled constitutes a temperature control system for a limited volume, since the inertia I of the temperature control system is based on a thermal inertia K for the volume, so the thermal inertia K can be estimated based on the comparison of the actual input process with Strans_act. the corresponding expected immersion process Strans_exp • The actual state value Sact utgOr has an actual temperature Tact for the limited volume and the actual temperature Tact is controlled against the reference value Sref, which consists of a reference temperature Tref for the volume.

The model for the temperature control system takes into account a difference between a change Tact of an actual temperature for the volume and a change Hit of a reference temperature for this volume. The difference depends on the hdr of the time parameter T and the equation according to the model of the temperature control system, which has an appearance according to: Pk-Fi = K * (Tref -TactTa. Ct) + Pk I dd./.(equ. 5) Pk + 1 Or a thermal power which will be emitted in the limited volume at the next iteration of the algorithm; K Or the thermal inertia of the limited volume; - Tref Or reference temperature; -Tact is the actual temperature; -T Or the time parameter; Tact is a change in the actual temperature; and k Or a current thermal effect which is emitted in the limited volume.

The aggressiveness of the immersion process for the actual temperature Tact against the reference temperature Tref can be easily set by adjusting the value of the model time parameter T, whereby the nature of the immersion process is changed as described in detail above. According to an embodiment of the present invention, the system to be regulated constitutes an arbitrary lamp system connected to a power take-off in a vehicle. Some vehicles, such as trucks and tractors, have power outlets to which a user can connect at the start what equipment is being lifted, such as a crane, a cement mixer, or different types of power units. The large variation between the different types of systems that can be connected to the power take-off means that a regulator with a relatively large number of different properties is required to operate these systems in a satisfactory manner.

A total moment of inertia J0 including a moment of inertia J for an engine in the vehicle and a moment of inertia h ,, for the power take-off system are estimated according to this embodiment based on the actual state value S „t, which is an actual speed waa for an engine in the vehicle and which turns towards a respective corresponding reference value Sref which constitutes a reference speed co „f for the engine. By estimating the total moment of inertia [tot for both engine and PTO shaft, the actual speed wact required for driving the PTO shaft can be regulated.

The model of the system takes into account a difference between a change w -Cza of an actual speed for the engine and a change w -7: ef of a reference speed for the engine, where the difference depends on time parameters The regulation of the system connected to the power take-off may have been given an Unwanted character / aggressiveness through a simple adjustment of the time parameter T.

According to this embodiment, the control of the system according to the above-described embodiments is made oscillation-free, i.e. the control of the state is made non-oscillative, by giving the time parameter T a value which is at least four times greater than the value of the calibration time y,> 4 * y. When T> 4 * y, the trapping Strans act takes place for the actual state value Sact against the reference value S, f completely without Upper and / or lower hoses. Oscillations in the actual capture process Strans _act for the actual value versus the reference value are avoided ants & di T 4 * y.

According to another embodiment, the time parameter T is given a value that Or at least more On four times said start as the value gets the calibration time y, T> 4 * y. For example, the time parameter T can be given the value 5 * y, T = 5 * y, which gives an additional 20% stability T = 4 * y. The higher value for the time parameter T can also be used, for example T = 6 * y, or T = 7 * y, which gives further oscillation in the control. The higher values for the time parameter T can be used to give further input.

According to one embodiment, an earlier estimate of the inertia / is considered to be inaccurate and / or a joke reliable in the actual capture process. Strans differs from the corresponding expected capture process. Strans_exp • At least one ratio between an earlier estimate P of the inertia and the actual value based on an analysis of the actual capture process Stransaal, which will then be shown.

In the analysis of the capture process Strans_act for the actual state value against the reference value Sref compares according to the present invention the appearance of the actual capture process Strans_actl for example for the actual velocity vaa, with a Preferred appearance for the same capture process, for example with a Preferred speed two trapping processes differ in that it may be due to the estimation of the mass being incorrect, which means that the regulation according to the invention becomes somewhat inaccurate, whereby the actual speed warrants a different appearance than the horde fa. Therefore, the estimation of the mass must be adjusted based on this analysis of the oscillation process Swans act E'er to be able to estimate a ratio of between the actual mass m related to the system and the estimated mass, a mathematical analysis of an oscillation process is made, which is described below.

The system, for example a vehicle, follows the power equation (Newton's second law): in • a = Fdriv F • omgtvnt • ng (eq. 6) Di the system is really controlled by the controller, that is to say the controller for what it requests and the control system is not located in mating to maximum torque or slack torque, the velocity profile of the actual velocity will fall to a predefined profile which depends only on the two parameters T and 7, which can be deduced as below.

The system is controlled, when the controller really controls, by the equation: hm * iv — v refact, ka act, k Fk + 1 = + Fk, dar (eq. 7) - Fk + 1 is a force which will be related to the system at the next iteration; - has a discretionary factor; 26 537 144 y is a calibration time; m is the mass related to the system; v „f is the reference speed; V act, k is the actual velocity; - 1- dr time parameter; a act, k is the actual acceleration; and F1, is a current force which is related to the system.

By combining the power equation (Equation 6) and the power update equation (Equation 7), the expression is obtained: maact L * rtM (V ref - V act, k + Fomgivning, k + maact, k (Equ. 8) Fomgivning, k + 1, k + 1 7 a act, k T Assume that the ambient forceAmIng is constant from one sample to another, which is a reasonable assumption in, for example, a speed control system, which is relatively slow.DA is obtained after some algebraic refurnishing the expression: (1 m * (v „f Vact, k aact, ka act, k + 1) 0 —a act, k 7 M (eq. 9) If the velocity error is defined as above C = vref-vact and man (61 act, ka act, k + 1 uses that term the numerical derivative of the acceleration is obtained instead of the following ordinal differential equation of the second order of the velocity error, but one also converts from discrete time to continuous time: 1-1, - u = - --FE (eq. 10) 7 27 537 144 gut is the ratio between the mass estimated m hitherto and the actual mass in From equation 10, the mass ratio t can be easily read out and calculated.

The problem is that both E and E are often very noisy, which is why the estimate thus also often becomes noisy.

To minimize the problem of noise in food signals, the equation is integrated from the fact that the controller really starts to steer the vehicle at time t = 0 until the system has stabilized around the reference after time t = T.

Then an expression is obtained for the mass ratio according to: (0) - (T) (eq. 11) TT (E (T) _E (0)) + JE (t) dt 0 days: E = S „f — Sact is a state error ; is a derivative of the state error E; - y Or a calibration time; r Or a time parameter; and the time period [0,7] has a length that states that the actual state value S „t has time to stabilize around the corresponding reference value Sref.

For example, for a cruise control system, where the actual state value Saa is an actual speed vaa and the corresponding reference value Sref is a reference speed v „f, the state error E is a speed error, E = vrefVact • If a braking system, where the actual state value S„ t is a actual velocity vaa and the respective corresponding 28 537 144 reference value S „f outputs a maximum velocity vmax, the state error E outputs a velocity error, C = vmax.

If equation 10 is lost, it is obtained Above the expected capture process Strans_exp • The expected capture process Strans_exp has an appearance which the actual capture process Stransact would have had if the control system had had access to a correct value for the fidelity /.

For systems where the condition error C constitutes a velocity error, such as for the cruise control system and the braking system, according to an embodiment of the invention the ratio 1.1 = - can be used to determine a new estimate of a mass related to the system, for example a vehicle mass, by updating an earlier mass estimate. by multiplying the old estimate m * by the calculated mass ratio (eq. 12) This can be repeated at each capture S - transact food reference Sref • A person skilled in the art realizes that the corresponding harling can also be done for the brake system at reference speed vref is replaced by the maximum speed Equation 12 is easy to implement in a discrete control system and it is guaranteed to converge as long as the actual velocity vaa converges towards the reference velocity v „f.

A non-limiting simulated example of mass estimation according to this embodiment is shown in Figures 4a and 4b, where the solid curve corresponds to an indentation S - transact where the mass estimation is correct and the dotted curve corresponds to an indentation. For the correct mass estimate, the inlet Strans becomes actoscillation-free (shown in Figure 4a) and the mass ratio 1.1 = 1 (shown in Figure 4h).

For the incorrect mass estimate, the inflow has an overshoot (shown in Figure 4a) and the mass ratio 11 = 0.5 (shown in Figure 4b). Mass Or hdr thus 50% underestimated.

Figure 4b clearly shows that the algorithm converges towards the mass ratio values g = 1 and 1.1 = 0.5, respectively, for correct and incorrect mass estimation, respectively, which makes the algorithm very useful for correcting incorrect mass estimates. In addition, the algorithm can be implemented with much added complexity addition.

If an acceleration limitation system, where the actual state value Sact is an actual acceleration aact and the reference value Sr-ef is a reference acceleration aref, the analysis can be based on a force equation related to the system, for example for a vehicle, according to: aact (T) - (0 ) 1-t7 T a „f (t) dt + va„ (0) - va „(T) (eq. 13) ddr: aact Or an actual acceleration; aref Or a reference acceleration; - V act Or an actual speed; y Or a calibration time; and the time period [0,7] has a length which ensures that the actual acceleration a -aa has time to stabilize around the reference acceleration a „f. Equation 13 looks different from Equation 11 because the acceleration limitation system has control over a reference acceleration are! and not at a reference speed v „f.

Even for the acceleration limitation system, the ratio can be = -1; used to determine a new estimate of the mass by updating an earlier estimate; ///=m*A.t, which can be deduced in the same way as for the cruise control system above.

For an engine system in the vehicle, where the actual state value Sact is an actual speed waa fer the engine and the corresponding reference value Sref is a reference speed co „f for the engine, the state error E in equation 6 is a speed error, E ° ref —Wact • Har kan, in the same way as the mass ratio pt = - / * is used to determine a new estimate Lew of moment of inertia by updating an earlier estimate j, inew = j which can be deduced in the same way as for the mass estimate above.

If there is a temperature control system in the vehicle, where the actual state value Sact is an actual temperature Tact for a limited volume and the corresponding reference value Sref is a reference temperature T, f for the volume, the state error E is a temperature error, E = Tref — Tact. Has can, in the same way as the mass ratio = - be used to determine a new estimate K of the thermal inertia by updating an earlier estimate K = K * • p ,, which can be deduced in the same way as for the mass estimate above. For a PTO system in the vehicle, where the actual state value Sact is an actual speed waa for an engine in a vehicle and the respective corresponding reference value Sref is a reference speed coref for the engine, CO -. the condition E = refCOact andsfelet E is a speed errorHar can, in the same way as for the mass quotient pt = -1; is used to determine a new estimate tot — new of the total moment of inertia by updating a previous estimate to j: new = tot. R, which can be deduced in the same way as for the mass estimate above.

According to an embodiment of the present invention, the controller, which is arranged to control at least one actual state value Scict against at least one respective corresponding reference value Sref, is constituted by a PID controller, or by a differential PI controller.

A PID controller is a controller which provides an input signal u (t) to a system to be controlled based on a deviation e (t) between a desired output signal r (t), i.e. the reference value, and an actual output signal y (t). ). Below it holds that e (t) = r (t) - y (t) according to: dt. '(Dt, (eq. 14) days: Kp is a gain constant; K1 is an integration constant; and - KD is a derivative constant. 537 144 A PID controller regulates in three ways, through a proportional gain (P; Kr), through an integration (I; Ki), and through a derivation (D; Kd).

The constants Kr, K1 and Kd affect the system as follows.

An increased value for the gain constant Kr leads to the following change of the PID controller: increased speed; reduced stability, improved compensation of process failures; and - increased control signal activity.

An Increased value for the integration constant Ki leads to the following change of the PID controller: better compensation of law-frequency process disturbances (eliminates residual errors in step disturbances); - Increased speed; and decreased stability An increased value for the derivative constant Kd leads to the following change of the PID controller: increased speed - increased stability increased control signal activity.

There are also other types / variants of controllers / control algorithms which have a function similar to that of the PID controller. Even when controlling with these other 33 537 144 types / variants of controllers / control algorithms, fidelity estimation according to the present invention can be used, which will be appreciated by a person skilled in the art.

A differential PI controller is a PI controller, ie without the D-part of the PID controller, which is expressed in differential form. The differential PI controller can be implemented in a discrete system.

According to an embodiment of the present invention, the estimation of the inertia / dive is performed based on information related to a road section where a vehicle is located, where this information may include a road slope c for the road section. The road inclination can be obtained based on one or more of the map data, a positioning device such as GPS (Global Positioning System), an accelerometer, a force equation and an altitude change.

Those skilled in the art will appreciate that the above-described method of the present invention may additionally be implemented in a computer program, which when executed in a computer causes the computer to execute the method. The computer program usually consists of a computer program product 503 stored on a digital storage medium, where the computer program is included in a computer program product's computer-storable medium. The aforementioned computer-capable media consists of a readable memory, such as: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc .

Figure 5 schematically shows a control unit 500. The control unit 500 comprises a bending unit 501, which can be made of substantially any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an application Specific Integrated Circuit (ASIC) function. The calculation unit 501 Or is connected to a memory unit 502 arranged in the control unit 500, which provides the calculation unit 501 e.g. the stored program code and / or the stored data calculation unit 501 need to be able to perform calculations. Calculation unit 501 Or Above arranged to store partial or final results of calculations in the memory unit 502.

Furthermore, the control unit 500 is provided with devices 511, 512, 513, 514 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the input signals receiving devices 511, 513 may be detected as information and may be converted into signals which may be processed by the calculating unit 501. These signals are then provided to the calculating unit 501. The devices 512 , 514 for transmitting output signals are arranged to convert signals received from the computing unit 501 for creating output signals by e.g. modulate the signals, which can be transmitted to other parts of the control system and / or to systems controlled according to the present invention.

Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may be one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Orientated Systems Transport bus), or any other bus configuration; or by a wireless connection.

One skilled in the art will appreciate that the above-mentioned computer may be constituted by the computing unit 501 and that the above-mentioned memory may be constituted by the memory unit 502. 537 144 General control systems in modern vehicles consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units ( ECUs, or controllers, and various components located on the vehicle. Such a control system may comprise a large number of control units, and the responsibility for a specific function may be divided into more than one control unit. Vehicles of the type shown thus often comprise considerably more control units than what is shown in Figure 5, which is a choice for those skilled in the art.

The present invention is in the embodiment shown implemented in the control unit 500. However, the invention can also be implemented in whole or in part in one or more other control units already existing at the vehicle or in a control unit dedicated to the present invention.

According to one aspect of the present invention, there is provided an estimation system for estimating an inertia / for a state in a system, wherein at least one controller is arranged to regulate at least one actual state value Sact against at least one respective corresponding reference value Sref in the system. The estimation system for estimating inertia comprises a determination unit arranged to determine at least one actual capture process. The transact value is at least one actual state value Sact against the at least one respective corresponding reference value Sref. The system for estimating the inertia / also comprises a comparison unit arranged to perform at least one comparison of the at least one actual capture process Strans act with at least one respective corresponding expected capture process Strans_exp and an estimation unit arranged to estimate the inertia / based on that at least one comparison. The person skilled in the art also realizes that the above system can be modified according to the various embodiments of the method according to the invention. In addition, the invention relates to a motor vehicle, for example a truck or a bus, comprising at least one control system and a system for estimating an inertia / according to the invention.

The present invention is not limited to the above-described embodiments of the invention but relates to and includes all embodiments within the scope of the appended independent claims. 37

Claims (23)

A method for a control system comprising a controller, wherein said At least one controller is arranged to control at least one actual state value Sact against at least one respective corresponding reference value Sref in a vehicle system which comprises an inertia / for said at least one actual state value Sact; characterized in that said control system is arranged to: 1. determine at least one actual capture process Strans_act for said at least one actual state value Sact against said at least one respective corresponding reference value Sref; 2. perform at least one comparison of said at least one actual capture sequence -Strans_act with at least one respective corresponding expected capture sequence Strans_exp where said expected capture sequence S -trans_eam has an appearance which would have been the result of said actual capture sequence -transact had the correct value for the said inertia /; 3. estimate namnda.troghet / based on namnda Atmin at least a comparison; and 4. controlling, using said controller, said at least one actual state value Sact against said At least one respective corresponding reference value Sref, wherein said control is model based and uses a control signal which has a magnitude proportional to a change of said at least one actual The condition according to claim 1, wherein said at least one regulator is based on a model, wherein said model comprises a force equation or other equation which is related to said vehicle system. The method of claim 2, wherein 1. said model comprises said At least an actual state value Sart, which is related to said vehicle system; 2. said At least one actual conditional Sact has said fidelity; and 3. at least one controller controls by utilizing a control signal, where a magnitude of said control signal is proportional to a change in said at least one actual state value Sart. A method according to claim 3, wherein 1. at least one actual condition value Scut constitutes an actual speed vact related to said vehicle system, Said at least one respective corresponding reference value Sref constitutes a reference speed vref related to said vehicle system, 3. said inertia / is related to a mass m related to said vehicle system; and 4. said mass must be estimated based on said estimated fidelity I. The method of claim 4, wherein said model takes into account a difference between an actual acceleration act for said vehicle system and a reference acceleration are! for said vehicle system, where said difference depends on a time parameter T. A method according to any one of claims 4-5, wherein said vehicle system is a cruise control system in a vehicle and said mass m constitutes a vehicle mass. 39 537 144 A method according to claim 3, wherein - said At least an actual state value S "t constitutes an actual acceleration acia related to said vehicle system; 1. said at least one respective corresponding reference value Sref constitutes a reference acceleration are! related to said vehicle system; 2. said fidelity I is based on a mass m related to said vehicle system; and 3. said mass must be estimated based on said estimated fidelity I. The method of claim 7, wherein said model takes into account a difference between said actual acceleration acia and said reference acceleration aref for said vehicle system. A method according to any one of claims 7-8, wherein said vehicle system is a system for acceleration limitation in a vehicle and said mass m constitutes a vehicle mass. The method of claim 3, wherein 1. said at least one actual state value Scat is an actual velocity vact related to said vehicle system; 2. said at least one respective corresponding reference value Siref constitutes a maximum speed vmax for said vehicle system; Said fidelity / based on a mass m related to said vehicle system; and - said mass must be estimated based on said estimated fidelity. A method according to claim 10, wherein said model takes into account a difference between an actual acceleration aact for said vehicle system and a reference acceleration aref for 537 144 said vehicle system, wherein said difference depends on a time parameter T. A method according to any one of claims 10-11, wherein said vehicle system is a system for braking a vehicle and said mass m constitutes a vehicle mass. The method of claim 3, wherein 1. said vehicle system comprises an engine; 2. said At least one actual state value S "t constitutes an actual speed coma for said motor; - said At least one respective corresponding reference value Sref constitutes a reference speed coref for said engine; 3. said inertia / is based on a moment of inertia J for said motor; and 4. said moment of inertia J is estimated based on said estimated inertia I. A method according to claim 13, wherein said model takes into account a difference between a change üJC of an actual speed for said motor and a change 04.1 of a reference speed for said motor, said difference being due to a time parameter T. The air conditioner of claim 3, wherein 1. said vehicle system is a temperature control system; 2. said At least one actual state value Sact constitutes an actual temperature Tact for a limited volume; - said At least one respective corresponding reference value Srej constitutes a reference temperature Tref for the said volume; 3. said inertia / based 0 a thermal inertia K for said volume; and 41 537 144 4. said thermal inertia K is estimated based on said estimated inertia. The method of claim 15, wherein said model takes into account a difference between a change Tact of an actual temperature for said volume and a change Tref of a reference temperature for said volume, wherein said difference depends on a time parameter T. A method according to claim 3, wherein 1. said vehicle system is a power take-off system at the Open driveline of a vehicle; 2. said at least one actual state value Saa constitutes an actual speed coact for an engine in said vehicle; 3. named at least one respective corresponding reference value Sref uts a reference speed core! for the said engine; - said inertia / is based on a total moment of inertia threat including an inertia moment J for an engine in said vehicle and a moment of inertia Jpro for said power take-off system; and - said total moment of inertia threat is estimated based on said estimated inertia I. The method of claim 17, wherein said model takes into account a difference between a change aliwt of an actual speed for said engine and a change üef of a reference speed for said engine, said difference being due to a time parameter T. The method of claim 1, wherein said at least one controller is a PID controller. 42 537 144 The method of claim 1, wherein said at least one regulator is a differential PI regulator. A method according to any one of claims 1-20, wherein an earlier estimate / * of said inertia / is considered to be inaccurate if said at least one actual capture process Strans _act differs from said at least one respective corresponding captured capture process Strans _e xp A method according to any one of claims 1-21, wherein At least one ratio = —r between an earlier estimate / * of said fidelity and said fidelity / is determined based on an analysis of said at least one actual capture process Strans_act • 23. A method according to claim 22, wherein said at least one ratio = - is determined based on the equation: / 1 = r i. (0) - (T) Zig (T) 61 (0+ fe (t) dt 0 days: 1. s = Sref — Sac , is a state error; 2. is a derivative of said state error e; - y is a calibration time; 3. T is a time parameter; and 4. the time period [OU] has a length that matters that said actual state value Sact is stabilized around said corresponding reference value. Ref. 43 537 144 24. A method according to claim 23, wherein 1. said analysis of said at least one actual capture process Strans_act is based on a force equation for - said vehicle system; - said at least one actual state value Sact constitutes an actual velocity vact for a vehicle; namnda atminston e a respective corresponding reference value Sref constitutes a reference speed vref for said vehicle; and 3. said state error is a velocity error, = vref vact - 25. A method according to claim 23, wherein 1. said analysis of said at least one actual capture process trans_act S is based on a force equation for - said vehicle system; 2. said at least one actual state value Sact utigtir an actual speed vact for a vehicle, 3. said at least one respective corresponding reference value Sref constitutes a maximum speed vmax for said vehicle; and 4. said state error e constitutes a velocity error, C = V —Vact. The method of claim 22, wherein said at least one ratio = - is determined based on the equation: 1 clacAT) - (0) P a „f (t) dt + Vac, (0) - vac, (T) dar: 1. aact is an actual acceleration; 2. aref is a reference acceleration; Guard is an actual speed; 3. y is a calibration time; and 4. the time period has a length which is such that the actual acceleration aaa is stabilized around said reference acceleration aref. A method according to any one of claims 22-26, wherein said quotient is used to determine a new estimate of a mass related to said vehicle system by updating an earlier estimate / r / * of said mass; m: w = 11-I • A method according to claim 23, wherein 1. said analysis of said & at least one actual capture process S -tratts_act is based on a force equation for said vehicle system; 2. said & at least one actual condition value Sact represents an actual speed waa for an engine in a vehicle; 3. said & at least one respective corresponding reference value Siref constitutes a reference speed coref for said engine; and - said state error e constitutes a speed error, e = corefC ° act • A method according to claim 28, wherein said quotient * is used to determine a new estimate Lew of a moment of inertia of said motor by updating an earlier estimate j of said moment of inertia ; J .0. The method of claim 28, wherein said ratio p = 7 is used to determine a new estimate Lot_new of a total moment of inertia including a moment of inertia J for said engine and a moment of inertia Any) for a power take-off system in said vehicle by updating a previous estimation Jm of the said moment of fidelity; Ifo, '_ new = jco: ./ 1 ° 31. A method according to claim 23, wherein - said & at least one actual state value S „t constitutes a 537 144 actual temperature Tact for a limited volume; 1. said at least one respective corresponding reference value Siref constitutes a reference temperature Tref for said volume; and 2. said state error 6 constitutes a temperature error, e = 7, .ef — Ta „. A method according to claim 31, wherein said ratio = - is used to determine a new estimate Ar :, „of a thermal inertia for said limited volume by updating a previous estimate A: * of said thermal inertia; A method according to any one of claims 1-32, wherein said estimating said fidelity is performed based on information related to a road section where said vehicle system is located. The method of claim 33, wherein said information comprises a vagal slope a of said vagal section. A method according to any one of claims 33-34, wherein said information is obtained based on at least one in the group of: 1. map data; a positioning device; 2. an accelerometer; 3. a force equation; 4. a height change. A computer program comprising program code, which when said program code is executed in a computer, causes said computer to execute the method according to any of claims 1-35. A computer program product comprising a computer readable medium and a computer program according to claim 36, wherein said computer program is included in said computer readable medium. A control system comprising a controller, wherein said at least one controller is arranged to control at least one actual state value Sact against At least one respective corresponding reference value Sref in a vehicle system which comprises a fidelity / for said At least one actual state value Sact; characterized by 1. a determination unit arranged to determine at least one actual capture sequence S -trans_act for said At least one actual state value Sact against said at least one respective corresponding reference value Sref; A comparison unit arranged to perform At least one comparison of said at least one actual capture sequence S trans_act with at least one respective corresponding expected capture sequence S - trans_exp, wherein said expected capture sequence S trans_exp has an appearance which would have been the result of said actual transaction act. the said system of rules had had access to the correct values for the said fidelity /; A estimating unit arranged to estimate said fidelity / based on said at least one comparison; and 4. a controller arranged to control said at least one actual state value Sact against said at least one respective corresponding reference value Sref, wherein said control is model based and uses a control signal which has a magnitude proportional to a change of said at least one actual state value Sact, and where said change depends on said fidelity. 47 537 144 1 / 101. Determine the actual capture process Strans act for actual state value against the corresponding reference value 102. Compare the actual capture process Strans act with the respective corresponding expected capture process Strans exp 103. Estimate the fidelity I based on comparison in step 102 Fic. 1 ningaf rned dika vaiten pi 7 Insng.% ■■■■■%. 537 144 2 / 24A 24. 3 24. 2 23 23. 7% 111111111 21N 2200 27300: 2400 250 2E00 NW 2300 2900 Strackapl Fic. 2 2 537 144 3 /