Testing system for drive-train

Patent metadata

Field	Value
Publication number	US-9459181-B2
Application number	US-201414898402-A
Country	US
Kind code	B2
Filing date	Jun 18, 2014
Priority date	Jun 19, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Provided is a testing system which is able to reproduce road surfaces in different states between both right and left tires. A testing system is provided with: a tire speed calculation unit which calculates virtual left and right tire speed values; a vehicle speed calculation unit which calculates a virtual vehicle speed value; a vehicle drive torque calculation unit which calculates left and right vehicle drive torque values; a differential torque calculation unit which calculates left and right differential torque values; and a speed control device which outputs a torque current command signal such that a deviation between a speed command value and a value detected by an encoder is eliminated. The tire speed calculation unit calculates the tire speed value on the basis of the differential torque values and the vehicle drive torque values.

First claim

The invention claimed is:

1. A drive train testing system comprising:
a dynamometer that is connected to an output shaft of a test piece;
an inverter that supplies electric power in response to a command signal to the dynamometer;
an axial torque detector that detects an axial torque acting on the output shaft;
a speed detector that detects a rotation speed of the dynamometer;
a tire speed calculation unit that calculates speed values of first and second tires respectively connected to a pair of output shafts of a virtual differential device connected to the output shaft of the test piece;
a vehicle speed calculation unit that calculates a speed value of a virtual vehicle traveling by using the first and second tires as drive wheels;
a vehicle driving torque calculation unit that calculates a first vehicle driving torque value generated by a friction force between the first tire and a virtual first road surface and a second vehicle driving torque value generated by a friction force between the second tire and a virtual second road surface based on the first and second tire speed values and the vehicle speed value;
a differential torque calculation unit that calculates a first differential torque value and a second differential torque value generated in the pair of output shafts of the differential device based on a detection value of the axial torque detector; and
a speed control device that outputs a command signal so that a deviation between a detection value of the speed detector and a speed command value calculated based on the first and second tire speed values disappears,
wherein the tire speed calculation unit calculates the first tire speed value based on the first differential torque value and the first vehicle driving torque value and calculates the second tire speed value based on the second differential torque value and the second vehicle driving torque value.

2. The drive train testing system according to claim 1 ,
wherein the differential torque calculation unit calculates the first differential torque value and the second differential torque value by multiplying the detection value of the axial torque detector by a predetermined first torque distribution ratio and a second torque distribution ratio so as to simulate a torque distribution function of the differential device.

3. The drive train testing system according to claim 2 ,
wherein the differential torque calculation unit calculates the first differential torque value by multiplying the detection value of the axial torque detector by the first torque distribution ratio and a predetermined gear ratio of the differential device, and calculates the second differential torque value by multiplying the detection value of the axial torque detector by the second torque distribution ratio and the gear ratio.

4. The drive train testing system according to claim 3 ,
wherein the speed control device sets a value obtained by multiplying an average value of the first tire speed value and the second tire speed value by a predetermined gear ratio of the differential device as a speed command value.

5. The drive train testing system according to claim 4 , further comprising:
a braking device that decelerates a rotation of the output shaft of the test piece; and
a decelerating torque calculation unit that calculates a decelerating torque value of the output shaft based on the detection value of the axial torque detector, the detection value of the speed detector, and a value of a command signal to the inverter.

6. The drive train testing system according to claim 3 , further comprising:
a braking device that decelerates a rotation of the output shaft of the test piece; and
a decelerating torque calculation unit that calculates a decelerating torque value of the output shaft based on the detection value of the axial torque detector, the detection value of the speed detector, and a value of a command signal to the inverter.

7. The drive train testing system according to claim 3 , further comprising:
a first braking calculation unit that calculates a first braking torque value generated in the first tire side of the output shaft in the differential device by a virtual braking device; and
a second braking torque calculation unit that calculates a second braking torque value generated in the second tire side of the output shaft in the differential device by the braking device,
wherein the tire speed calculation unit calculates the first tire speed value based on a value obtained by subtracting the first vehicle driving torque value and the first braking torque value from the first differential torque value, and calculates the second tire speed value based on a value obtained by subtracting the second vehicle driving torque value and the second braking torque value from the second differential torque value,
wherein the first braking torque calculation unit sets a predetermined braking torque command value as an upper limit value, and calculates the first braking torque value so that the first braking torque value is smaller than the upper limit value and the first tire speed value becomes 0, and
wherein the second braking torque calculation unit sets a predetermined braking torque command value as an upper limit value, and calculates the second braking torque value so that the second braking torque value is smaller than the upper limit value and the second tire speed value becomes 0.

8. The drive train testing system according to claim 7 ,
wherein the first braking torque calculation unit limits the braking torque command value at a predetermined change rate or less, sets the limited first braking torque value as an upper limit value, and calculates the first braking torque value so that the first braking torque value is smaller than the upper limit value and the first tire speed value becomes 0, and
wherein the second braking torque calculation unit limits the braking torque command value at a predetermined change rate or less, sets the limited second braking torque value as an upper limit value, and calculates the second braking torque value so that the second braking torque value is smaller than the upper limit value and the second tire speed value becomes 0.

9. The drive train testing system according to claim 2 ,
wherein the speed control device sets a value obtained by multiplying an average value of the first tire speed value and the second tire speed value by a predetermined gear ratio of the differential device as a speed command value.

10. The drive train testing system according to claim 9 , further comprising:
a braking device that decelerates a rotation of the output shaft of the test piece; and
a decelerating torque calculation unit that calculates a decelerating torque value of the output shaft based on the detection value of the axial torque detector, the detection value of the speed detector, and a value of a command signal to the inverter.

11. The drive train testing system according to claim 2 , further comprising:
a braking device that decelerates a rotation of the output shaft of the test piece; and
a decelerating torque calculation unit that calculates a decelerating torque value of the output shaft based on the detection value of the axial torque detector, the detection value of the speed detector, and a value of a command signal to the inverter.

12. The drive train testing system according to claim 2 , further comprising:
a first braking torque calculation unit that calculates a first braking torque value generated in the first tire side of the output shaft in the differential device by a virtual braking device; and
a second braking torque calculation unit that calcu

Assignees

• Meidensha Electric Mfg Co Ltd

Inventors

• Akiyama Takao
• Sawada Yoshimasa

Classifications

• G01L3/24

  Devices for determining the value of power, e.g. by measuring and simultaneously multiplying the values of torque and revolutions per unit of time, by multiplying the values of tractive or propulsive force and velocity · CPC title

• G01M13/025 Primary

  Test-benches with rotational drive means and loading means; Load or drive simulation · CPC title

• G01L3/02

  Rotary-transmission dynamometers · CPC title

• G01M17/007 Primary

  Wheeled or endless-tracked vehicles (G01M17/08 takes precedence) · CPC title

• G01M15/044

  by monitoring power, e.g. by operating the engine with one of the ignitions interrupted; by using acceleration tests · CPC title