CN100416551C - Control point smoothing method based on preceding deviation - Google Patents

Abstract

The present invention discloses a control point smoothing method based on preceding deviation, which dynamically adjusts the positions of control points based on the preceding prediction deviation to realize the smoothing processing of remote-range control points. The present invention is the improvement of a Dead-reckoning method which utilizes speed and acceleration parameters of an object to carry out dynamic prediction. The present invention not only utilizes the speed and the acceleration of the object, but also utilizes the past deviation to carry out micro adjustment. Thus, the present invention has the advantages that the prediction precision to the movement of the control points is improved; the control point smoothing method makes up undesirable results brought by the judder of a network; smooth mobile traces of the remote control points are shown to users; a better perception effect can be attained.

Description

Reference mark smoothing method based on preceding deviation

Technical field

The present invention relates to the computer supported cooperative work field, particularly relate to a kind of reference mark smoothing method based on preceding deviation.

Background technology

One of 20th century mankind's outstanding achievement computer technology has been brought human society into the information age.Be accompanied by deepening continuously of IT application process, the communication technology, computing machine and network technology merge mutually, have produced a new research field-computer supported cooperative work CSCW (Computer SupportedCooperative Work).

As collaborative design person during in co-operation, the monitoring Long-distance Control locus of points can help the user to understand preferably and predict other devisers' intention.The change procedure that represents long-range pattern objects is for supporting that collaborative work is of great value means.Yet usually there is the instability of delay in network, also is called shake (jitter), and this may cause representing under the real time environment the inaccurate of remote participant activity.Shake can cause the discontinuous of Long-distance Control point motion track, causes the user to misread or even operating collision.In order to relax the negative effect brought of shake, adopt usually based on known historical position and predict that Long-distance Control puts the method for next position, with the track of skimulated motion, reach level and smooth natural effect.

There is certain limitation in track following (Tracing) technology at present, the main mutual effect that adopts the Dead-reckoning method to improve player and distributed objects in the internet game on-line.The Dead-reckoning method has been utilized speed, the acceleration parameter of object, shows good effect in the moving process based on the strong inertial mass of mechanics.The Dead-reckoning Forecasting Methodology is applied to equally cuts down the shake effect that move at the reference mark, experimental results show that this prediction can improve in the group system immediacy and naturality mutual between the user.Yet the prediction accuracy of Dead-reckoning under this application still has much room for improvement.

Summary of the invention

The object of the present invention is to provide a kind of reference mark smoothing method based on preceding deviation.

The technical scheme that the present invention solves its technical matters employing is as follows:

1) the Long-distance Control point of the nearest N of record within second is in the shift position of each millisecond;

2) when network jitter takes place, for the shift position of PREDICTIVE CONTROL point, at first calculation control point is used aveVelocity at the present speed of directions X and Y direction _XAnd aveVelocity _YRepresent; Present speed is by from current nearest T _LastPosition coordinates (X constantly _Last, Y _Last) and the preceding T of M millisecond _FlagPosition coordinates (the X that constantly receives _Flag, Y _Flag) calculate;

$\left\{\begin{array}{c}\mathrm{aveVelocit}{y}_X=(X_{\mathrm{last}}-X_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ \mathrm{aveVelocit}{y}_Y=(Y_{\mathrm{last}}-Y_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

3) calculation control point is used aveAcceleration in the current acceleration of directions X and Y direction _XAnd aveAcceleration _YRepresent; Current acceleration is by from current nearest T _LastSpeed and T constantly _FlagSpeed is calculated constantly; Wherein, T _LastPosition constantly is (X _Last, Y _Last), T _FlagPosition constantly is (X _Flag, Y _Flag); T _FlagBe T constantly _LastThe moment before the moment M millisecond;

$\left\{\begin{array}{c}\mathrm{aveAcceleratio}{n}_X=({\mathrm{Velocity}}_{\mathrm{Xlast}}-{\mathrm{Velocity}}_{\mathrm{Xflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ \mathrm{aveAcceleratio}{n}_Y=({\mathrm{Velocity}}_{\mathrm{Ylast}}-{\mathrm{Velocity}}_{\mathrm{Yflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

Wherein:

Velocity _XlastBe that the reference mark is at horizontal ordinate directions X T _LastSpeed constantly;

Velocity _XflagBe that the reference mark is at horizontal ordinate directions X T _FlagSpeed constantly;

Velocity _YlastBe that the reference mark is at ordinate Y direction T _LastSpeed constantly;

Velocity _YflagBe that the reference mark is at ordinate Y direction T _FlagSpeed constantly;

4) calculation control point is represented with Δ x and Δ y respectively at the correcting value of horizontal ordinate directions X and ordinate Y direction, and Δ x is relevant with following factor with Δ y:

(1) preceding once horizontal ordinate (X, predicted value Y) when shake finishes;

(2) preceding corresponding horizontal ordinate (X, actual value Y) that receives when finishing of once shaking;

(3) current shake time-delay;

(4) preceding once shake time-delay, if system is prediction for the first time, the value of Δ x and Δ y is 0;

The formula that calculates Δ x and Δ y is:

$\left\{\begin{array}{c}\mathrm{\Δx}=(X_{\mathrm{true}}-X_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\\ \mathrm{\Δy}=(Y_{\mathrm{true}}-Y_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\end{array}\right.$

Wherein:

X _LastIt is the value of last horizontal ordinate X of predicting in the preceding network jitter process;

X _TrueIt is last the horizontal ordinate X actual value that is blocked by the shake time-delay in the preceding network jitter process;

Y _LastIt is the value of last ordinate Y of predicting in the preceding network jitter process;

Y _TrueIt is last the ordinate Y actual value that is blocked by the shake time-delay in the preceding network jitter process;

JitterLapse is current shake time-delay;

Once shake time-delay before the JitterPeriod;

C is an adjustment factor;

5) the current location note at reference mark is (X _Current, Y _Current), and the next position note at reference mark is (X _Next, Y _Next), when network jitter takes place, (X _Next, Y _Next) calculate by following formula:

$\left\{\begin{array}{c}{X}_{\mathrm{next}}=X_{\mathrm{current}}+\mathrm{aveVelocit}{y}_X*T+\mathrm{aveA}{\mathrm{cceleration}}_X*T^2+\mathrm{\Δx}\\ Y_{\mathrm{next}}=Y_{\mathrm{current}}+\mathrm{aveVelocit}{y}_Y*T+\mathrm{aveAcceleratio}{n}_Y*T^2+\mathrm{\Δy}\end{array}\right.$

Wherein:

T is current shake time-delay, is equal to JitterLapse;

6) with the position (X of Long-distance Control point according to prediction _Next, Y _Next) be plotted on user's the screen;

7) wipe the reference mark of previous prediction, draw the reference mark of up-to-date prediction, the rest may be inferred, and complete in the reference mark of all predictions in dither process.

The present invention compares with background technology, and the useful effect that has is:

The deviation that the present invention is based on last time prediction is dynamically adjusted the position at reference mark, realizes that the smoothing of Long-distance Control point is handled.The present invention improves the Dead-reckoning method, the Dead-reckoning method has utilized the speed of object, acceleration parameter to carry out performance prediction, and the present invention has not only used speed, the acceleration of object, and utilized deviation in the past to carry out the adjustment of trace, improved the precision of prediction of reference mark motion.Remedy the bad result that network jitter brings, show the level and smooth Long-distance Control point motion track of user, reach perceived effect preferably.

Embodiment

Specific implementation flow process based on the reference mark smoothing method of preceding deviation is as follows.

1) the Long-distance Control point of the nearest N of record within second is in the shift position of each millisecond;

For example, can write down position data within nearest 2 seconds.

2) when network jitter takes place, for the shift position of PREDICTIVE CONTROL point, at first calculation control point is used aveVelocity at the present speed of directions X and Y direction _XAnd aveVelocity _YRepresent; Approximate velocity is by from current nearest T _LastPosition coordinates (X constantly _Last, Y _Last) and the preceding T of M millisecond _FlagPosition coordinates (the X that constantly receives _Flag, Y _Flag) calculate;

$\left\{\begin{array}{c}\mathrm{aveVelocit}{y}_X=(X_{\mathrm{last}}-X_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ \mathrm{aveVelocit}{y}_Y=(Y_{\mathrm{last}}-Y_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

For example, the M value is got 100 milliseconds, promptly 0.1 second.T _LastPosition coordinates constantly is (310,320), T _FlagThe position coordinates that constantly receives is (300,300), coordinate all with pixel as unit.

3) calculation control point is used aveAcceleration in the current acceleration of directions X and Y direction _XAnd aveAcceleration _YRepresent; Approximate acceleration is by from current nearest T _Last(X constantly _Last, Y _Last) speed and the T of position _Flag(X constantly _Flag, Y _Flag) another speed of position calculates;

$\left\{\begin{array}{c}\mathrm{aveAcceleratio}{n}_X=({\mathrm{Velocity}}_{\mathrm{Xlast}}-{\mathrm{Velocity}}_{\mathrm{Xflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ \mathrm{aveAcceleratio}{n}_Y=({\mathrm{Velocity}}_{\mathrm{Ylast}}-{\mathrm{Velocity}}_{\mathrm{Yflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

Suppose T _Last(X constantly _Last, Y _Last) speed of position is (100,100), acceleration calculation is as follows so:

4) calculation control point is represented with Δ x and Δ y respectively at the correcting value of directions X and Y direction, and Δ x is relevant with following factor with Δ y:

(1) preceding once (X, predicted value Y) when shake finishes;

(2) preceding corresponding (X, actual value Y) that receives when finishing of once shaking;

(3) current shake time-delay;

(4) preceding once shake time-delay.If system is prediction for the first time, the value of Δ x and Δ y is 0;

The formula that calculates Δ x and Δ y is:

$\left\{\begin{array}{c}\mathrm{\Δx}=(X_{\mathrm{true}}-X_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\\ \mathrm{\Δy}=(Y_{\mathrm{true}}-Y_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\end{array}\right.$

Wherein:

X _LastIt is the coordinate of last X of predicting in the preceding network jitter process;

X _TrueIt is last X true coordinate of being blocked by the shake time-delay in the preceding network jitter process;

Y _LastIt is the coordinate of last Y of predicting in the preceding network jitter process;

Y _TrueIt is last Y true coordinate of being blocked by the shake time-delay in the preceding network jitter process;

JitterLapse is current shake time-delay;

Once shake time-delay before the JitterPeriod;

C is an adjustment factor;

Suppose (X _Last, Y _Last)=(290,280), (X _True, Y _True)=(290,284) suppose JitterLapse=100 (ms), JitterPeriod=200 (ms) establishes C=0.5, has:

$\left\{\begin{array}{c}\mathrm{\Δx}=(290-290)*0.1*0.5/0.2=0\\ \mathrm{\Δy}=(284-280)*0.1*0.5/0.2=1\end{array}\right.$

5) the current location note at reference mark is (X _Current, Y _Current), and the next position note at reference mark is (X _Next, Y _Next), when network jitter takes place, (X _Next, Y _Next) calculate by following formula:

$\left\{\begin{array}{c}{X}_{\mathrm{next}}=X_{\mathrm{current}}+\mathrm{aveVelocit}{y}_X*T+\mathrm{aveA}{\mathrm{cceleration}}_X*T^2+\mathrm{\Δx}\\ Y_{\mathrm{next}}=Y_{\mathrm{current}}+\mathrm{aveVelocit}{y}_Y*T+\mathrm{aveAcceleratio}{n}_Y*T^2+\mathrm{\Δy}\end{array}\right.$

Wherein:

T is current shake time-delay, is equal to JitterLapse;

As above routine:

$\left\{\begin{array}{c}{X}_{\mathrm{next}}=310+100*0.1+0=320\\ Y_{\mathrm{next}}=320+200*0.1+1000*{0.1}^2+1=351\end{array}\right.$

6) with the position (X of Long-distance Control point according to prediction _Next, Y _Next) be plotted on user's the screen;

7) wipe the reference mark of previous prediction, draw the reference mark of up-to-date prediction, the rest may be inferred, and complete in the reference mark of all predictions in dither process.

Claims (1)

1. reference mark smoothing method based on preceding deviation is characterized in that:

1) the Long-distance Control point of the nearest N of record within second is in the shift position of each millisecond;

2) when network jitter takes place, for the shift position of PREDICTIVE CONTROL point, at first calculation control point is used aveVelocity at the present speed of directions X and Y direction _XAnd aveVelocity _YRepresent; Present speed is by from current nearest T _LastPosition coordinates (X constantly _Last, Y _Last) and the preceding T of M millisecond _FlagPosition coordinates (the X that constantly receives _Flag, Y _Flag) calculate;

$\left\{\begin{array}{c}\mathrm{aveVelocit}{y}_X=(X_{\mathrm{last}}-x_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ {\mathrm{aveVelocity}}_Y=(Y_{\mathrm{last}}-Y_{\mathrm{flag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

3) calculation control point is used aveAcceleration in the current acceleration of directions X and Y direction _XAnd aveAcceleration _YRepresent; Current acceleration is by from current nearest T _LastSpeed and T constantly _FlagSpeed is calculated constantly; Wherein, T _LastPosition constantly is (X _Last, Y _Last), T _FlagPosition constantly is (X _Flag, Y _Flag); T _FlagBe T constantly _LastThe moment before the moment M millisecond;

$\left\{\begin{array}{c}{\mathrm{aveAcceleration}}_X=({\mathrm{Velocity}}_{\mathrm{Xlast}}-{\mathrm{Velocity}}_{\mathrm{Xflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\\ {\mathrm{aveAcceleration}}_Y=({\mathrm{Velocity}}_{\mathrm{Ylast}}-{\mathrm{Velocity}}_{\mathrm{Yflag}})/(T_{\mathrm{last}}-T_{\mathrm{flag}})\end{array}\right.$

Wherein:

Velocity _XlastBe that the reference mark is at horizontal ordinate directions X T _LastSpeed constantly;

Velocity _XflagBe that the reference mark is at horizontal ordinate directions X T _FlagSpeed constantly;

Velocity _YlastBe that the reference mark is at ordinate Y direction T _LastSpeed constantly;

Velocity _YflagBe that the reference mark is at ordinate Y direction T _FlagSpeed constantly;

4) calculation control point is represented with Δ x and Δ y respectively at the correcting value of horizontal ordinate directions X and ordinate Y direction, and Δ x is relevant with following factor with Δ y:

(1) preceding once horizontal ordinate (X, predicted value Y) when shake finishes;

(2) preceding corresponding horizontal ordinate (X, actual value Y) that receives when finishing of once shaking;

(3) current shake time-delay;

(4) preceding once shake time-delay, if system is prediction for the first time, the value of Δ x and Δ y is 0;

The formula that calculates Δ x and Δ y is:

$\left\{\begin{array}{c}\mathrm{\Δx}=(X_{\mathrm{true}}-X_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\\ \mathrm{\Δy}=(Y_{\mathrm{true}}-Y_{\mathrm{last}})*\mathrm{JitterLapse}*C/\mathrm{JitterPeriod}\end{array}\right.$

Wherein:

X _LastIt is the value of last horizontal ordinate X of predicting in the preceding network jitter process;

X _TrueIt is last the horizontal ordinate X actual value that is blocked by the shake time-delay in the preceding network jitter process;

Y _LastIt is the value of last ordinate Y of predicting in the preceding network jitter process;

Y _TrueIt is last the ordinate Y actual value that is blocked by the shake time-delay in the preceding network jitter process;

JitterLapse is current shake time-delay;

Once shake time-delay before the JitterPeriod;

C is an adjustment factor;

5) the current location note at reference mark is (X _Current, Y _Current), and the next position note at reference mark is (X _Next, Y _Next), when network jitter takes place, (X _Next, Y _Next) calculate by following formula:

$\left\{\begin{array}{c}{X}_{\mathrm{next}}=X_{\mathrm{current}}+\mathrm{aveVelo}\cot y_X*T+{\mathrm{aveAcceleration}}_X*T^2+\mathrm{\Δx}\\ Y_{\mathrm{next}}=Y_{\mathrm{current}}+{\mathrm{aveVelocity}}_Y*T+{\mathrm{aveAcceleration}}_Y*T^2+\mathrm{\Δy}\end{array}\right.$

Wherein:

T is current shake time-delay, is equal to JitterLapse;

6) with the position (X of Long-distance Control point according to prediction _Next, Y _Next) be plotted on user's the screen;

7) wipe the reference mark of previous prediction, draw the reference mark of up-to-date prediction, the rest may be inferred, and complete in the reference mark of all predictions in dither process.