Method and apparatus for establishing virtual inertia in a chassis dynamometer
First Claim
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1. An apparatus for establishing virtual inertia in a dynamometer, said apparatus comprising:
- actuatable force producing means for, when actuated, applying a controllable amount of force to a device under test;
display means for displaying predetermined velocity values versus time graph;
means for monitoring velocity of said device under test; and
control means for comparatively displaying on said display means said monitored velocity value of said device under test against the predetermined velocity value and for controlling said actuatable force producing means to simulate inertia loads in accordance with said displayed predetermined velocity values.
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Abstract
A vehicle dynamometer system having at least one roller mounted in a frame for engagement with at least one driven wheel of a vehicle includes an eddy current brake for, when actuated, applying a controllable amount of force to the dynamometer roller. A display displays a graph of desired velocity values versus time graph. Vehicle speed is monitored. A controller comparatively displays on the display the monitored vehicle speed against the desired velocity value and controls the eddy current brake to simulate inertia loads in accordance with the displayed desired velocity values.
49 Citations
17 Claims
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1. An apparatus for establishing virtual inertia in a dynamometer, said apparatus comprising:
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actuatable force producing means for, when actuated, applying a controllable amount of force to a device under test; display means for displaying predetermined velocity values versus time graph; means for monitoring velocity of said device under test; and control means for comparatively displaying on said display means said monitored velocity value of said device under test against the predetermined velocity value and for controlling said actuatable force producing means to simulate inertia loads in accordance with said displayed predetermined velocity values. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for establishing virtual inertia in a dynamometer having at least one roller mounted in a frame for engagement with at least one driven wheel of a vehicle, said apparatus comprising:
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actuatable force producing means for, when actuated, applying a controllable amount of force to said at least one roller of said dynamometer; display means for displaying predetermined desired velocity values versus time graph; means for monitoring vehicle speed; and control means for comparatively displaying on said display means said monitored vehicle speed against the predetermined desired velocity value and for controlling said actuatable force producing means to simulate inertia loads in accordance with said displayed predetermined desired velocity values. - View Dependent Claims (8, 9, 10)
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11. A method for establishing virtual inertia in a dynamometer, said method comprising the steps of:
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applying a controllable amount of force to a device under test in response to a control signal; displaying predetermined desired velocity values versus time graph for said device under test; monitoring actual velocity of said device under test; and comparatively displaying the monitored velocity of said device under test against the predetermined desired velocity value of said device under test; providing said control signal to control said applied force and thereby simulate inertia loads in accordance with said displayed predetermined desired velocity value of said device under test. - View Dependent Claims (12, 13)
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14. A method for establishing virtual inertia in a dynamometer having at least one roller mounted in a frame for engagement with at least one driven wheel of a vehicle, said method comprising the steps of:
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applying a controllable amount of force to said at least one roller of said dynamometer in response to a control signal; displaying a predetermined desired velocity values versus time graph; monitoring vehicle speed; and comparatively displaying the monitored vehicle speed against the predetermined desired velocity value; providing said control signal to control said force and thereby simulate inertia loads in accordance with said displayed predetermined desired velocity values. - View Dependent Claims (15)
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16. An apparatus for establishing virtual inertia in a dynamometer having at least one roller mounted in a frame for engagement with at least one driven wheel of a vehicle, said apparatus comprising:
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actuatable force producing means for, when actuated, applying a controllable amount of force to said at least one roller of said dynamometer; display means for displaying desired velocity values versus time graph; means for monitoring vehicle speed; and control means for comparatively displaying on said display means said monitored vehicle speed against the desired velocity value and for controlling said actuatable force producing means to simulate inertia loads in accordance with said displayed desired velocity values, said control means applying an inertia load in accordance with;
space="preserve" listing-type="equation">Γ
.sub.TDAF =Γ
.sub.TRLF -Γ
.sub.PLF +Γ
.sub.IS -Γ
.sub.GTRLwhere Γ
TRLF is a value of track road load force, Γ
PLF is a value indicative of parasitic loss force, Γ
GTRL is the general tire roll interface losses, and Γ
IS is an inertia simulation force determined in accordance with;
##EQU7## where ETW is the vehicle test weight, DBI is a dynamometer equivalent inertia load, V1 is an initial velocity of the test vehicle in ft/sec, V2 is a final velocity of the vehicle in ft/sec, ET is an amount of time needed for the vehicle to change from the initial to the final velocity in seconds, and AVVrpm is the average value of the rpm'"'"'s of the dynamometer rollers at the measured vehicle speed determined by ##EQU8##
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17. A method for establishing virtual inertia in a dynamometer having at least one roller mounted in a frame for engagement with at least one driven wheel of a vehicle, said method comprising the steps of:
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applying a controllable amount of force to said at least one roller of said dynamometer in response to a control signal; displaying a desired velocity values versus time graph; monitoring vehicle speed; comparatively displaying the monitored vehicle speed against the desired velocity value; and providing said control signal to control said force and thereby simulate inertia loads in accordance with said displayed desired velocity values, said control signal being provided in accordance with;
space="preserve" listing-type="equation">Γ
.sub.TDAF =Γ
.sub.TRLF -Γ
.sub.PLF +Γ
.sub.IS -Γ
.sub.GTRLwhere Γ
TRLF is a value of track road load force, Γ
PLF is a value indicative of parasitic loss force, Γ
GTRL is the general tire roll interface losses, and Γ
IS is an inertia simulation force determined in accordance with;
##EQU9## where ETW is the vehicle test weight, DBI is a dynamometer equivalent inertia load, V1 is an initial velocity of the test vehicle in ft/sec, V2 is a final velocity of the vehicle in ft/sec, ET is an amount of time needed for the vehicle to change from the initial to the final velocity in seconds, and AVVrpm is the average value of the rpm'"'"'s of the dynamometer rollers at the measured vehicle speed determined by ##EQU10##
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Specification