Claims:STATEMENT OF CLAIMS
We claim,
1. A chassis dynamometer 100 for determining motoring loss and friction loss in an engine of an automatic transmission vehicle equipped with torque converter, said vehicle having at least one drive wheel 202, comprising:
at least one roller 102 adapted for driving the at least one wheel 202 of the vehicle;
an electric motor 104 and a power absorption unit 106 connected to the roller 102, wherein the roller 102, the electric motor 104 and the power absorption unit 106 are mounted on a frame;
at least one load sensor 108 adapted for determining a load provided by the engine and a drivetrain of the vehicle;
at least one pressure sensor adapted for determining a pressure inside at least one cylinder in the engine of the vehicle;
at least one speed sensor adapted for determining speed of the roller 102;
a control unit 110adapted for determining motoring loss and friction loss in the engine, wherein the load sensor 108,the pressure sensor and the speed sensor are provided in communication with the control unit 110;
and
a data acquisition system in communication with the control unit 110; wherein the data acquisition system is configured to receive at least one signal from the control unit 110, and convert the received at least one signal into digital value.

2. The chassis dynamometer 100 as claimed in claim 1, wherein the chassis dynamometer further includes a display unit in communication with the data acquisition system to display the digital values.

3. A method 300 for determining a wheel power and an indicated pressure in an engine204 of a vehicle200 using a chassis dynamometer 100, said method comprising:
mounting the vehicle 200 on the chassis dynamometer 100;
warming up the engine 204 and a drivetrain of the vehicle;
setting the engine 204 of the vehicle in a firing state;
setting the chassis dynamometer 100 to a speed regulated mode;
driving at least one roller 102 of the chassis dynamometer 100 to rotate the drive wheel in a forward direction;
setting a power transmission unit 208 of the vehicle in a predetermined gear position;
engaging the power transmission unit 208 to the engine204 by engaging a torque converter 206 of the vehicle;
driving the engine204 at a predetermined speed;
measuring a wheel power through a control unit 110of the chassis dynamometer 100;and
measuring a pressure inside at least one cylinder in the engine 204 through a pressure sensor of the chassis dynamometer 100 through the control unit 110.

4. A method 400 for determining a churning loss and a drivetrain loss in a vehicle 200 using a chassis dynamometer 100, said method comprising:
mounting the vehicle 200 on the chassis dynamometer 100;
warming up the engine 204 and a drivetrain of the vehicle;
setting the engine 204 of the vehicle in a non-firing state;
setting the chassis dynamometer 100 to a speed regulated mode;
driving at least one wheel 202 of the vehicle 200 through at least one roller 102 of the chassis dynamometer 100 in a reverse direction;
setting a power transmission unit 208 of the vehicle in a predetermined gear position;
engaging the power transmission unit 208 to the engine 204 by engaging a torque converter 206 of the vehicle;
driving the roller 102 at a predetermined speed; and
measuring a wheel power through a control unit 110of the chassis dynamometer 100.

5. A method 500 for determining a drivetrain loss in a vehicle 200 using a chassis dynamometer 100, said method comprising:
draining automatic transmission fluid from a torque converter 206 of the vehicle;
mounting the vehicle on the chassis dynamometer 100;
warming up the engine 204 and a drivetrain of the vehicle;
setting the engine 204 of the vehicle 200 in a non-firing state;
setting the chassis dynamometer 100 to a speed regulated mode;
driving at least one wheel 202 of the vehicle through at least one roller 102 of the chassis dynamometer in a reverse direction;
setting a power transmission unit 208 of the vehicle in a predetermined gear position;
driving the roller 102 at a predetermined speed; and
measuring a wheel power through a control unit 110of the chassis dynamometer 100.

6. A method 600 for determining a drivetrain loss in a vehicle 200 using a chassis dynamometer 100, said method comprising:
draining automatic transmission fluid from a torque converter 206 of the vehicle;
mounting the vehicle on the chassis dynamometer 100;
warming up the engine 204 and a drivetrain of the vehicle;
setting the engine 204 of the vehicle 200 in a non-firing state;
setting the chassis dynamometer 100 to a speed regulated mode;
driving at least one wheel 202 of the vehicle through at least one roller 102 of the chassis dynamometer 100 in a forward direction;
setting a power transmission unit 208 of the vehicle in a predetermined gear position;
driving the roller 102 at a predetermined speed; and
measuring a wheel power through a control unit 110of the chassis dynamometer 100.

7. A method 700 for determining power loss due to churning in a vehicle 200 using a chassis dynamometer 100, said method comprising:
determining a churning loss of a torque converter 206 and a drivetrain loss in reverse direction according to the method 400 as claimed in claim 4;
determining a drivetrain loss in reverse direction according to the method 500 as claimed in claim 5; and
deducing the power loss due to churning in a vehicle200 based on the difference between thedetermined churning loss of a torque converter and a drivetrain loss in reverse direction according to the method 400 as claimed in claim 4 and the determined drivetrain loss in reverse direction according to the method 500 as claimed in claim 5.

8. A method 800 for determining brake power of an engine 204 of a vehicle 200 using a chassis dynamometer 100, said method comprising:
determining wheel power of the vehicle 200 according to the method 300 as claimed in claim 3;
determining power loss due to churning in the vehicle 200 according to the method 700 as claimed in claim 7;
determining a drivetrain loss in the vehicle 200 according to the method 600 as claimed in claim 6; and
deducing the brake power of the vehicle by addition of the determined wheel power according to the method 300 as claimed in claim 3, the determined power loss due to churning according to the method 700 as claimed in claim 7 and the determined drivetrain loss according to the method 600 as claimed in claim 6.

9. A method 900 for determining motoring loss in a vehicle 200 using a chassis dynamometer 100, said method comprising:
measuring an indicated power of an engine 204 using a data acquisition system;
determining a brake power of the engine 204 according to the method 800 as claimed in claim 8; and
deducing the motoring loss by deducting brake power of the engine from the indicated power of the engine of the vehicle 200.

10. A method for determining a friction loss in an engine 204 of a vehicle 200 using a chassis dynamometer 100, said method comprising:
determining a motoring loss in the engine 204 of the vehicle 200 according to the method 900 as claimed in claim 9;
measuring a pressure inside at least one cylinder in the engine through a pressure sensor of the chassis dynamometer 100 for determining a pumping loss in the engine 204 through a control unit 110;and
deducing the friction loss in the engine based on the difference between the motoring loss and the pumping loss in the engine 204 through the control unit 110.
, Description: The present application is a Patent of Addition of Application No. 3979/CHE/2015 filed with the Indian Patent Office on 31. 07.2015, the disclosure of which is hereby incorporated by reference herein.

TECHNICAL FIELD
The embodiments herein generally relate to engine testing in vehicles and more particularly but not exclusively to engine testing in vehicles using chassis dynamometer.

BACKGROUND
Generally, an engine of a vehicle is tested using an engine dynamometer for determining the emission values, durability, motoring loss, friction loss, pumping loss of an engine etc. Testing a vehicle’s engine through an engine dynamometer is a time consuming process as the engine needs to be dismantled from the vehicle and mounted on to the test bed of engine dynamometer for testing. Further, the testing involves the replication of wiring harness setup in test bed of the engine dyanamometer and emulation of requisite sensor signals necessary for proper operation of the electronic control unit (ECU) of the engine. Hence, the original setting of the engine invariably gets disturbed in the process and the vehicle is also rendered unusable during the testing period.
Therefore, there exists a need for a simple method for testing motoring and friction loss of an engine while it is still mounted on the vehicle. Furthermore, there exists a need for a method that eliminates the afore-mentioned drawbacks.

OBJECTS
The principle object of an embodiment of this invention is to provide a simple method for testing an engine of a vehicle using a chassis dynamometer for determining the motoring loss in the engine.
Another object of an embodiment of this invention is to provide a simple method for testing an engine of a vehicle using a chassis dynamometer for determining the friction loss in the engine.
These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
FIG. 1 depicts a schematic of the chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 2a depicts a vehicle mounted to the chassis dynamometer with the engine engaged to the power transmission unit of the vehicle to determine wheel power, according to an embodiment of the invention as disclosed herein;
FIG. 2b depicts a vehicle mounted to the chassis dynamometer to determine churning loss of torque converter and drivetrain loss of the automatic transmission vehicle with engine at OFF condition, according to an embodiment of the invention as disclosed herein;
FIG. 2c depicts a vehicle mounted to the chassis dynamometer and driven in reverse direction to determine drivetrain loss of the vehicle with automatic transmission fluid being drained from the torque converter, according to an embodiment of the invention as disclosed herein;
FIG. 2d depicts a vehicle mounted to the chassis dynamometer and driven in forward direction to determine drivetrain loss of the vehicle with automatic transmission fluid being drained from the torque converter, according to an embodiment of the invention as disclosed herein;
FIG. 3 depicts a flow chart of a method for determining wheel power and indicated pressure in an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 4 depicts a flow chart of a method determining a churning loss of torque converter and a drivetrain loss of automatic transmission vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 5 depicts a flow chart of a method for determining a drivetrain loss in a vehicle using a chassis dynamometer without using automatic transmission fluid and a chassis dynamometer roller to rotate the drive wheel in reverse direction, according to an embodiment of the invention as disclosed herein;
FIG. 6 depicts the flow chart of a method for determining drivetrain loss in an automatic transmission vehicle after draining automatic transmission fluid in torque converter and using a chassis dynamometer with roller to rotate the drive wheel in forward direction, according to an embodiment of the invention as disclosed herein;
FIG. 7 depicts a flow chart of a method for determining power loss due to churning in a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 8 depicts a flow chart of a method for determining brake power of an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 9 depicts a flow chart of a method for determining motoring loss in a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein;
FIG. 10 depicts a flow chart of a method for determining a friction loss in an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein; and
FIG. 11 depicts a sample schematic PV diagram for a 4-Stroke Engine, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The embodiments herein achieve a simple method for testing an engine of a vehicle using a chassis dynamometer for determining the motoring loss in the engine. Further, embodiments herein achieve a method for testing an engine of a vehicle using a chassis dynamometer for determining the friction loss in the engine. Referring now to the drawings, and more particularly to FIGS. 1 through 10, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
FIG. 1 depicts a schematic of the chassis dynamometer according to an embodiment of the invention as disclosed herein. The chassis dynamometer 100 includes, at least one roller 102, an electric motor/generator104, a power absorption unit 106, at least one load sensor 108, a control unit 110, at least one pressure sensor (not shown), at least one speed sensor (not shown), a data acquisition system (not shown), a display unit (not shown), a power supply (not shown) and a frame (not shown).
In an embodiment, a vehicle 200 to be tested includes at least one wheel 202, at least one engine 204, at least one torque converter 206, at least one power transmission unit 208, at least one propeller shaft and/or drive shaft (not shown), a wheel axle (not shown) and/or a differential (not shown). In an embodiment, the torque converter 206, the power transmission unit 208, the propeller shaft and/or drive shaft, the wheel axle and the differential constitute the drivetrain (not shown) of the vehicle. However, it is also within the scope of the invention that drivetrain (not shown) of the vehicle 200 may include any other components without otherwise deterring the intended function of the drivetrain (not shown) as can be deduced from the description. In an embodiment the drivetrain (not shown) is used for delivering the power from the engine 204 to the wheels 202 of the vehicle 200 for propulsion. In an embodiment, the power transmission unit 208 includes a plurality of gears (not shown). In an embodiment the vehicle 200 to be tested is a four wheeled vehicle. However, it is also within the scope of the invention to test two wheeled vehicles or vehicles with any number of wheels without otherwise deterring the intended function of the chassis dynamometer 100.
In an embodiment, the chassis dynamometer 100 includes the roller 102 used for driving the wheels 202 of a vehicle 200. The roller 102 is driven by the electric motor/generator 104 for driving the wheels 202 of the vehicle 200. In an embodiment the chassis dynamometer includes two rollers 102 (one for driving left wheel and one for driving right wheel). However, it is also within the scope of the invention to provide any number of rollers 102 without otherwise deterring the intended function of the roller 102 as can be deduced from the description. In an embodiment, the chassis dynamometer 100 is associated with its own power absorption unit 106 and power supply. In an embodiment, the load sensor 108 is connected with a housing (not shown) of the electric motor/generator 104 for measuring the load/torque provided by the engine and/or drivetrain of the vehicle. In an embodiment, the load sensor 108 is a load cell. However, it is also within the scope of the invention to provide any other type of load sensor 108 without otherwise deterring the intended function of the load sensor 108 as can be deduced from the description.
In an embodiment, the control unit 110 includes a display unit (not shown), at least one logic circuit (not shown), at least one control switch (not shown) for setting the chassis dynamometer 100 in speed regulated mode, at least one control switch (not shown) for setting the speed of the roller 102, at least one switch (not shown) for setting speed of a fan 112 and at least one switch for operating power supply. In an embodiment, the control unit 110 is provided in communication with the load sensor 108 for determining the motoring loss and friction loss in the engine 204 of the vehicle 200. In an embodiment, the control unit 110 described herein can include for example, but not limited to, microprocessor, microcontroller, controller, smart phone, portable electronic device, communicator, tablet, laptop, computer, consumer electronic device, a combination thereof, or any other device capable of processing signals.
In an embodiment, the control unit 110 is provided in communication with the data acquisition system (not shown). In an embodiment, the data acquisition system is configured to receive at least one signal from the control unit 110 and convert the received at least one signal into digital value.
In an embodiment, the control unit 110 determines the motoring loss (measured in Kilowatt) in the engine 204 based on the following equation,
Motoring loss (Mp) = Indicated Power - Brake Power,
where,
The indicated power is obtained by using the data acquisition system(DAS) which measures in-cylinder pressure, crank angle and engine speed amongst other variables.
The engine brake power is obtained by adding churning loss (CF) and drivetrain losses (DTLF) to wheel power (Pw).
In an embodiment, the pumping loss (measured in Newton metre) in the engine 204 is measured using the formula,
Fig. 11 depicts a sample schematic PV diagram for a 4-Stroke Engine

Pumping loss (Wp) = (Area B + Area C) as shown in above fig. a
PMEP=W_p/V_d
PMEP = Pumping mean effective pressure in ‘N/m2’
Wp = Pumping work done in ‘Nm’ or ‘J’
In an embodiment, the friction loss in (measured in Newton metre) the engine is measured using the formula,
Friction loss = Motoring loss – Pumping loss
In an embodiment, the pressure sensor (not shown) is used for measuring a pressure inside at least one cylinder (not shown) in the engine 204for determining a pumping loss in the engine 204. The pressure sensor (not shown) is provided in communication with the control unit 110. The pressure sensor (not shown) provides input to the control unit 110 for determining the pumping loss in the engine 204. In an embodiment the pressure sensor (not shown) is provided at the place (not shown) of glowplug/sparkplug (not shown) in the engine 204 for measuring the pressure in the cylinder (not shown) of the engine 204.However, it is also within the scope of the invention to provide the pressure sensor (not shown) at any other location in the engine 204 without otherwise deterring the intended function of the pressure sensor as can be deduced from the description. In an embodiment, the power supply (not shown) is used for powering the electric motor/generator 104, and the control unit 110. In an embodiment the frame (not shown) is used for mounting the vehicle 200 over the chassis dynamometer 100 for testing the engine 204.
FIG. 3 depicts a flow chart of a method for determining wheel power and indicated pressure in an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 300 for determining wheel power and indicated pressure in an engine of a vehicle using a chassis dynamometer includes, mounting the vehicle on the chassis dynamometer 100 (step 302), warming up the engine 204 and drivetrain of the vehicle (step 304), setting the engine 204 of the vehicle in a firing state (step 306), setting the chassis dynamometer 100 to a speed regulated mode (step 308), driving at least one roller 102 of the chassis dynamometer 100 to rotate the drive wheel in a forward direction through at least one wheel of the vehicle 202 (step 310), setting a power transmission unit 208 of the vehicle in a predetermined gear position (step 312), engaging the power transmission unit 208 to the engine 204 by engaging a torque converter 206 of the vehicle (step 314), driving the engine 204 at a predetermined speed (step 316), measuring a wheel power through a control unit 110 of the chassis dynamometer 100 (step 318), and measuring a pressure inside at least one cylinder in the engine 204 through a pressure sensor (not shown) of the chassis dynamometer 100 through the control unit 110 (step 320).
The working of the chassis dynamometer 100 in conjunction with the method 300 for determining the wheel power and the indicated pressure in the engine of the vehicle is as follows. FIG. 2a depicts a vehicle mounted to the chassis dynamometer with the engine engaged to the power transmission unit of the vehicle to determine wheel power, according to an embodiment of the invention as disclosed herein.
First the vehicle 200 is mounted on the chassis dynamometer 100and the engine 204 and the drivetrain is warmed up. Then the engine 204 is set in firing state by switching ON an ignition system (not shown) of the engine 204. Based on the type of vehicle 200 the appropriate wheels 202 of the vehicle 200 are provided in contact with the rollers 102. For example if the vehicle 200 to be tested is a rear wheel drive vehicle the rear wheels of the vehicle 200 are provided in contact with the rollers 102. The chassis dynamometer 100 is set to speed regulated mode through the control unit 110. Thereafter, the wheel 202 of the vehicle 200 starts driving the appropriate rollers 102 of the chassis dynamometer at a minimum speed. In an embodiment, the roller 102 to rotate the drive wheel in a forward direction. Thereafter the power transmission unit 208 is set to a predetermined gear position, for example, 3rd gear. Then the power transmission unit 208 is engaged to the engine 204 as shown in Fig. 2a. In an embodiment engaging the power transmission unit 208 to the engine 204 is done using the torque converter 206. As the rollers 102 of the chassis dynamometer102are driven by the wheels 202 of the vehicle 200, the drivetrain (wheel axle, the differential, the propeller shaft, the power transmission unit 208, the torque converter206) and the components of the engine 204 such as crankshaft (not shown), camshaft (not shown), pistons (not shown), valves (not shown) etc., are driven as the power transmission unit 208 is engaged to the engine 204. Thereafter the rollers 102 of the chassis dynamometer 100are driven at a predetermined speed. In an embodiment the predetermined speed is based on the low idle governing speed and maximum speed of the set gear position of the power transmission unit 208i.e the predetermined speed values shall be selected between the low idle governing speed and maximum vehicle speed of the gear position selected in the power transmission unit during testing. Further, the roller 102 of the chassis dynamometer 100 rotates at the predetermined speed and the control unit 110 records the power available at the wheel 202. In an embodiment, the predetermined speed of the roller is increased in steps of 5 or 10 kmph to record the work power at each step. Further, a pressure inside at least one cylinder in the engine is measured through the pressure sensor (not shown). Thereafter the torque converter 206 is disengaged through draining of torque converter fluid and hence the power transmission unit 208 is disengaged from the engine 204.
FIG. 4 depicts a flow chart of a method determining a churning loss and a drivetrain loss in a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 400 for determining a churning loss and a drivetrain loss in a vehicle using a chassis dynamometer includes, mounting the vehicle on the chassis dynamometer 100 (step 402), warming up the engine 204 and a drivetrain of the vehicle (step 404), setting the engine 204 of the vehicle in a non-firing state (step 406), setting the chassis dynamometer 100 to a speed regulated mode (step 408), driving at least one wheel 202 of the vehicle through at least one roller 102 of the chassis dynamometer 100 to rotate the drive wheel in a reverse direction (step 410), setting a power transmission unit 208 of the vehicle in a predetermined gear position (step 412), engaging the power transmission unit 208 to the engine 204 by engaging a torque converter 206 of the vehicle (414), driving the roller 102 at a predetermined speed (step 416) and measuring a wheel power through a control unit 110 of the chassis dynamometer 100 (step 418).
The working of the chassis dynamometer 100 in conjunction with the method 400 for determining a churning loss and a drivetrain loss in a vehicle using a chassis dynamometer is as follows. FIG. 2b depicts a vehicle mounted to the chassis dynamometer to determine churning loss and drivetrain loss of the vehicle with engine at OFF condition, according to an embodiment of the invention as disclosed herein.
First the vehicle 200 is mounted on the chassis dynamometer 100and the engine 204 and the drivetrain is warmed up. Then the engine 204 is set in non-firing state by switching OFF an ignition system (not shown) of the engine 204. Based on the type of vehicle 200 the appropriate wheels 202 of the vehicle 200 are provided in contact with the rollers 102. For example, if the vehicle 200 to be tested is a rear wheel drive vehicle the rear wheels of the vehicle 200 are provided in contact with the rollers 102. The chassis dynamometer 100 is set to speed regulated mode through the control unit 110. Thereafter, the rollers 102 of the chassis dynamometer 100 starts driving the appropriate wheels 202 of the vehicle 200 at a minimum speed. In an embodiment, the roller is configured to rotate the drive wheel in a reverse direction. Thereafter the power transmission unit 208 is set to a predetermined gear position, for example, 3rd gear. Then the power transmission unit 208 is engaged to the engine 204 as shown in Fig. 2b. In an embodiment engaging the power transmission unit 208 to the engine 204 is done using the torque converter 206. As the wheels202 of the vehicle 200 are driven by the rollers 102 of the vehicle 200, the drivetrain (wheel axle, the differential, the propeller shaft, the power transmission unit 208, the torque converter 206) and the components of the engine 204 such as crankshaft (not shown), camshaft (not shown), pistons (not shown), valves (not shown) etc., are driven as the power transmission unit 208 is engaged to the engine 204. Thereafter the rollers 102 of the chassis dynamometer 100 are driven at a predetermined speed. In an embodiment, the predetermined speed is based on the low idle governing speed and maximum speed of the set gear position of the power transmission unit 208 i.e the predetermined speed values shall be selected between the low idle governing speed and maximum vehicle speed of the gear position selected in the power transmission unit during testing. As the rollers 102 of the chassis dynamometer 100 rotates at the predetermined speed and the control unit 110 records the power available at the wheel 202. In an embodiment, the predetermined speed of the roller is increased in steps of 5 or 10 kmph to record the work power at each step. Thereafter the torque converter 206 is disengaged and the power transmission unit 208 is disengaged from the engine 204.
FIG. 5 depicts a flow chart of a method for determining a drivetrain loss in a vehicle using a chassis dynamometer without using automatic transmission fluid and a drive wheel operated in reverse direction, according to an embodiment of the invention as disclosed herein. The method 500 for determining a drivetrain loss in a vehicle using a chassis dynamometer includes, draining automatic transmission fluid from a torque converter 206 of the vehicle (step 502), mounting the vehicle on the chassis dynamometer 100 (step 504), warming up the engine 204 and a drivetrain of the vehicle (step 506), setting the engine 204 of the vehicle in a non-firing state (step 508), setting the chassis dynamometer 100 to a speed regulated mode (step 510), driving at least one wheel 202 of the vehicle through at least one roller 102 of the chassis dynamometer to rotate the drive wheel in a reverse direction (step 512), setting a power transmission unit 208 of the vehicle in a predetermined gear position (step 514), driving the roller 102 at a predetermined speed (step 516) and measuring a wheel power through a control unit 110 of the chassis dynamometer 100 (step 518).
The working of the chassis dynamometer 100 in conjunction with the method 500 for determining a drivetrain loss in a vehicle using a chassis dynamometer without using automatic transmission fluid and a roller to rotate the drive wheel in reverse direction is as follows. FIG. 2c depicts a vehicle mounted to the chassis dynamometer and driven in reverse direction to determine drivetrain loss of the vehicle with automatic transmission fluid being drained from the torque converter, according to an embodiment of the invention as disclosed herein.
First the automatic transmission fluid is drained from the torque converter 206 of the vehicle 200. Then the vehicle 200 is mounted on the chassis dynamometer 100 and the drivetrain is warmed up. Then the engine 204 is set in non-firing state by switching OFF an ignition system (not shown) of the engine 204. Based on the type of vehicle 200 the appropriate wheels 202 of the vehicle 200 are provided in contact with the rollers 102. For example, if the vehicle 200 to be tested is a rear wheel drive vehicle the rear wheels of the vehicle 200 are provided in contact with the rollers 102. The chassis dynamometer 100 is set to speed regulated mode through the control unit 110. Thereafter, the rollers 102 of the chassis dynamometer 100 starts driving the appropriate wheels 202 of the vehicle 200 at a minimum speed. In an embodiment, the roller to rotate the drive wheels in a reverse direction. Thereafter the power transmission unit 208 is set to a predetermined gear position, for example, 3rd gear. In an embodiment, thereafter the torque converter 206 is disengaged through draining of torque converter fluid and hence the power transmission unit 208 is disengaged from the engine 204 as shown in Fig. 2c. Thereafter the rollers 102 of the chassis dynamometer 100 are driven at a predetermined speed. In an embodiment, the predetermined speed is based on the low idle governing speed and maximum speed of the set gear position of the power transmission unit 208 i.e the predetermined speed values shall be selected between the low idle governing speed and maximum vehicle speed of the gear position selected in the power transmission unit during testing. As the rollers 102 of the chassis dynamometer 100 rotates at the predetermined speed and the control unit 110 records the power available at the wheel 202. In an embodiment, the predetermined speed of the roller is increased in steps of 5 or 10 kmph to record the work power at each step.
FIG. 6 depicts the flow chart of a method for determining drivetrain loss in an automatic transmission vehicle after draining automatic transmission fluid in torque converter and using a chassis dynamometer with roller to rotate the drive wheel in forward direction, according to an embodiment of the invention as disclosed herein. The method 600 for determining drivetrain loss in a vehicle using a chassis dynamometer includes, draining automatic transmission fluid from a torque converter 206 of the vehicle (step 602), mounting the vehicle on the chassis dynamometer 100 (step 604), warming up the engine 204 and a drivetrain of the vehicle (step 606), setting the engine 204 of the vehicle in a non-firing state (step 608), setting the chassis dynamometer 100 to a speed regulated mode (step 610), rotating drive wheel 202 of the vehicle through roller 102 of the chassis dynamometer 100 in a forward direction (step 612), setting a power transmission unit 208 of the vehicle in a predetermined gear position (step 614), driving the roller 102 at a predetermined speed (step 616) and measuring a wheel power through a control unit 110 of the chassis dynamometer 100 (step 618).
The working of the chassis dynamometer 100 in conjunction with the method 600 for determining drivetrain loss in an automatic transmission vehicle after draining automatic transmission fluid in torque converter and using a chassis dynamometer with drive wheel operated in forward direction, according to an embodiment of the invention as disclosed herein. FIG. 2d depicts a vehicle mounted to the chassis dynamometer and driven in forward direction to determine drivetrain loss of the vehicle with automatic transmission fluid being drained from the torque converter, according to an embodiment of the invention as disclosed herein.
First the automatic transmission fluid is drained from the torque converter 206 of the vehicle 200. Then the vehicle 200 is mounted on the chassis dynamometer 100and the engine 204 and the drivetrain is warmed up. Then the engine 204 is set in non-firing state by switching OFF an ignition system (not shown) of the engine 204. Based on the type of vehicle 200 the appropriate wheels 202 of the vehicle 200 are provided in contact with the rollers 102. For example, if the vehicle 200 to be tested is a rear wheel drive vehicle the rear wheels of the vehicle 200 are provided in contact with the rollers 102. The chassis dynamometer 100 is set to speed regulated mode through the control unit 110. Thereafter, the rollers 102 of the chassis dynamometer 100 starts driving the appropriate wheels 202 of the vehicle 200 at a minimum speed. In an embodiment, the roller is configured to rotate the drive wheel in a forward direction. Thereafter the power transmission unit 208 is set to a predetermined gear position, for example, 3rd gear. In an embodiment, the power transmission unit 208 is disengaged to the engine 204 as shown in Fig. 2d. Thereafter the rollers 102 of the chassis dynamometer 100 are driven at a predetermined speed. In an embodiment, the predetermined speed is based on the low idle governing speed and maximum speed of the set gear position of the power transmission unit 208 i.e the predetermined speed values shall be selected between the low idle governing speed and maximum vehicle speed of the gear position selected in the power transmission unit during testing. As the rollers 102 of the chassis dynamometer 100 rotates at the predetermined speed and the control unit 110 records the power available at the wheel 202. In an embodiment, the predetermined speed of the roller is increased in steps of 5 or 10 kmph to record the work power at each step.
FIG. 7 depicts a flow chart of a method for determining power loss due to churning in a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 700 for determining power loss due to churning in a vehicle using a chassis dynamometer includes, determining a churning loss of a torque converter and a drivetrain loss in reverse direction according to the method 400 as claimed in claim 4 (step 702), determining drivetrain loss in reverse direction according to the method 500 as claimed in claim 5 (step 704), and deducing power loss due to churning in a vehicle based on the difference between the determined churning loss of a torque converter and drivetrain loss in reverse direction according to the method 400 as claimed in claim 4 and the determined drivetrain loss in reverse direction according to the method 500 as claimed in claim 5 (step 706).
The working of the chassis dynamometer 100 in conjunction with the method 700 for determining power loss due to churning in a vehicle using a chassis dynamometer is as follows.
First the churning loss of the torque converter 206 and drivetrain loss in reverse direction with automatic transmission fluid in torque converter are determined according to the method 400. Further, drivetrain loss in reverse direction without automatic transmission fluid in torque converter is determined according to the method 500. In an embodiment, the power loss due to churning in a vehicle is determined based on the difference between the determined churning loss of a torque converter and a drivetrain loss in reverse direction according to the method 400 and the determined drivetrain loss in reverse direction according to the method 500.
FIG. 8 depicts a flow chart of a method for determining brake power of an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 800for determining power loss due to churning in a vehicle using a chassis dynamometer includes, determining wheel power of the vehicle according to the method 300 (step 802), determining power loss due to churning in the vehicle according to the method 700 (step 804), determining a drivetrain loss in the vehicle according to the method 600 (step 806) and deducing the brake power of the vehicle by addition of the determined wheel power according to method 300, the determined power loss due to churning according to the method 700 and the determined drivetrain loss according to the method 600 (step 808).
The working of the chassis dynamometer 100 in conjunction with the method 800 for determining brake power of an engine of a vehicle using a chassis dynamometer is as follows.
Firstly, the wheel power of the vehicle is determined according to the method 300. Further, the power loss due to churning in the vehicle is determined according to the method 700. Furthermore, the drivetrain loss in the vehicle is deduced according to the method 600. Finally, the brake power of the vehicle is calculated by adding the determined wheel power according to method 300, the determined power loss due to churning according to the method 700 and the determined drivetrain loss according to the method 600.
FIG. 9 depicts a flow chart of a method for determining motoring loss in a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 900for determining motoring loss in a vehicle using a chassis dynamometer includes, measuring an indicated power of an engine using a data acquisition system (step 902), determining a brake power of the engine according to the method 800 (step 904) and deducing the motoring loss by deducting brake power of the engine from the indicated power of the engine of the vehicle (step 906).
The working of the chassis dynamometer 100 in conjunction with the method 900 for determining motoring loss in a vehicle using a chassis dynamometer is as follows.
Firstly, an indicated power of an engine is measured or recorded using the data acquisition system. Further, the brake power of the engine is determined according to the method 800. Finally, the motoring loss is determined by deducting brake power of the engine from the indicated power of the engine of the vehicle.
FIG. 10 depicts a flow chart of a method for determining a friction loss in an engine of a vehicle using a chassis dynamometer, according to an embodiment of the invention as disclosed herein. The method 1000for determining a friction loss in an engine of a vehicle using a chassis dynamometer includes, determining a motoring loss in the engine of the vehicle according to the method 900 (step 1002), measuring a pressure inside at least one cylinder in the engine through a pressure sensor of the chassis dynamometer 100 for determining a pumping loss in the engine 204 through a control unit 110 (step 1004) and deducing the friction loss in the engine based on the difference between the motoring loss and the pumping loss in the engine 204 through the control unit 110 (step 1006).
The working of the chassis dynamometer 100 in conjunction with the method 1000 for determining a friction loss in an engine of a vehicle using a chassis dynamometer is as follows.
Firstly, the motoring loss in the engine of the vehicle is determined according to the method 900 (step 1002). Further, a pressure inside the at least one cylinder in the engine is recorded through a pressure sensor of the chassis dynamometer 100 for determining a pumping loss in the engine 204 through a control unit 110 (step 1004). Finally, the friction loss in the engine is determined based on the difference between the motoring loss and the pumping loss in the engine 204 through the control unit 110 (step 1006).
The various actions, units, steps, blocks, or acts described in the method 300-1000can be performed in the order presented, in a different order, simultaneously, or a combination thereof. Further, in some embodiments, some of the actions, units, steps, blocks, or acts listed in the FIG. 3 and FIG. 10 may be omitted, added, skipped, or modified without departing from the scope of the invention.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Referral Numerals:
Chassis dynamometer 100
Roller 102
Motor 104
Power absorption unit 106
Load sensor 108
Control unit 110
Vehicle 200
Wheel 202
Engine 204
Torque converter 206
Power transmission unit 208