Computing a target speed in a virtual racing environment

Abstract

A target speed profile for a specified racer is computed at various points along a track. The calculation is based on the real world physics of the racing environment and incorporates physical characteristics of the track, including curvature, undulation, and/or camber. A lateral acceleration component is developed to limit the realistic maximum speed a racer may obtain at any given point along the track. Furthermore, differences in realistic maximum speeds at different points along the track can overwhelm a racer's braking capability. As such, braking capacity adjustments can be applied to decrease the maximum speed in the target speed profile, so that the overall target speed profile is more realistic and attainable.

What is claimed is: 
     
         1 . A method, performed by a computing device comprising a processor, storage, and a display, of setting a target speed, the method comprising:
 determining, by computations of the processor, a maximal lateral acceleration metric associated with the racer;   computing, by computations of the processor, the target speed as a function of the maximal lateral acceleration metric and as a function of an attribute of a model of a road or track;   recording the target speed in the storage; and   displaying on the display a speed or acceleration indicator based on the target speed.   
     
     
         2 . A method according to  claim 1 , wherein the speed indicator indicates whether the player should slow down based on the target speed and based on a current state of the simulation. 
     
     
         3 . A method according to  claim 2 , wherein the current state of the simulation comprises the current speed of the racer. 
     
     
         4 . A method according to  claim 1 , wherein the attribute comprises a value representing a geometric feature of the model of the road or track. 
     
     
         5 . A method according to  claim 4 , wherein the geometric feature corresponds to a curvature, a camber, or a slope of the model of the road or track. 
     
     
         6 . A method according to  claim 5 , wherein the curvature comprises horizontal curvature or vertical curvature. 
     
     
         7 . A method according to  claim 4 , wherein the geometric feature is specific to a race line or the model of the road or track. 
     
     
         8 . A method according to  claim 1 , wherein the maximal lateral acceleration metric represents a maximum lateral acceleration that allows the racer to travel on the track without losing traction in a virtual racing environment, and wherein if the racer exceeds the target speed the racer will, according to the virtual racing environment, lose traction. 
     
     
         9 . A computer-readable medium having computer-executable instructions that cause a computing device to perform a process that sets a target speed corresponding to a racing line, the process comprising:
 computing the target speed according to the racing line, wherein the target speed is computed such that the target speed corresponds to a speed at which a loss of traction will occur on the racing line;   recording the target speed in a storage medium; and   computing a suggestion graphic based on the target speed and displaying the suggestion graphic.   
     
     
         10 . A computer-readable medium according to  claim 9 , wherein the computing the suggestion graphic is further based on a current speed. 
     
     
         11 . A computer-readable medium according to  claim 9 , wherein the target speed is computed according to a curvature or camber that corresponds to the race line. 
     
     
         12 . A computer-readable medium according to  claim 11 , wherein the displayed suggestion graphic reflects a difference between a current speed and the target speed. 
     
     
         13 . A computer-readable medium according to  claim 9 , wherein the target speed is computed according to a maximum lateral acceleration metric that corresponds to a maximum lateral acceleration without sliding. 
     
     
         14 . A computer-readable medium according to  claim 9 , wherein the process further comprises:
 adjusting the target speed based on a braking capacity.   
     
     
         15 . A method of evaluating speed in a vehicle movement simulation executed by a computing device, the method comprising:
 computing a plurality of target speeds for a travel path of the vehicle movement simulation, the target speeds being computed based on one or more curvatures and/or cambers corresponding to the travel path;   storing the target speeds; and   receiving current speeds and displaying indicators that, according to the target speeds and the current speeds, suggest increasing or decreasing speed.   
     
     
         16 . A method according to  claim 15 , wherein the indicators are also displayed such that a given indicator is displayed according to a given current speed value and a given target speed. 
     
     
         17 . A method according to  claim 15 , wherein the target speeds are computed to take into account a grip that increases with speed. 
     
     
         18 . A method according to  claim 15 , further comprising computing an overshoot and using the overshoot to compute a target speed. 
     
     
         19 . A method according to  claim 15 , wherein a plurality of lateral accelerations are computed and used to compute the target speeds, respectively. 
     
     
         20 . A method according to  claim 15 , wherein a target speed is computed according to a horizontal or vertical curvature and according to a camber.