WO2013158849A4

WO2013158849A4 - Method for automatically estimating inertia

Info

Publication number: WO2013158849A4
Application number: PCT/US2013/037122
Authority: WO
Inventors: Gang Tian
Original assignee: Linestream Technologies
Priority date: 2012-04-20
Filing date: 2013-04-18
Publication date: 2014-01-30
Also published as: TWI498701B; WO2013158849A3; WO2013158849A2; JP2017062824A; TW201351082A; KR101378824B1; JP2013225284A; KR20130122704A

Abstract

Systems and methods for estimating an inertia and a friction coefficient for a controlled mechanical system are provided. In one or more embodiments, an inertia estimator can generate a torque command signal' that varies continuously over time during a testing sequence. The velocity of a motion system in response to the time-varying torque command signal is measured and recorded during the testing sequence. The inertia estimator then estimates the inertia and/or the friction coefficient of the motion system based on the torque command data sent to the motion system and the measured velocity data. Systems and methods are also provided for generating a constraint-based, time-optimal motion profile for controlling the trajectory of a point-to-point move in a motion control system.

Claims

AMENDED CLAIMS

received by the International Bureau on 13 November 2013 (13.11.2013)

What is claimed is:

1 . A method for estimating parameters of a motion system, comprising:

generating a torque command signal that varies continuously over a time range, wherein the time range comprises an acceleration phase and a

deceleration phase;

measuring velocity data for a motion device representing a velocity of the motion system over the time range in response to the torque command signal; and

determining an inertia of the motion system based at least in part on a product of an integral of the velocity data over the acceleration phase and an integral of the torque command signal over the deceleration phase.

2. (Cancelled)

3. The method of claim 1 , wherein the generating the torque command signal comprises adjusting the torque command signal in accordance with a predefined testing sequence, wherein the adjusting includes changing at least one of a direction or a rate of change of the torque command signal in response to the velocity of the motion system reaching a predefined velocity checkpoint.

4. The method of claim 1 , wherein the determining comprises:

integrating the torque command signal and the velocity data over the acceleration phase to yield U_acc and V_aee, respectively;

integrating the torque command signal and the velocity data over the deceleration phase to yield U_iee and V_igc, respectively; and

determining the inertia as a function of u_aeCi v_aee, u_dgc, and v_deCi where:

70

tt_ari.(t) is a portion of the torque command signal corresponding to the acceleration phase,

vo*e( ^{is 3} portion of the velocity data corresponding to the acceleration phase,

tio^t) is a portion of the torque command signal corresponding to the deceleration phase, and

is a portion of the velocity data corresponding to the deceleration phase.

5. The method of claim 4, wherein the determining the inertia comprises determining the inertia according to:

U V — [j

J— dec acc acc v dec

where:

J is the inertia,

Av_aec (t) is a difference between a velocity of the motion system at an end of the acceleration phase and a velocity of the motion system at a beginning of the acceleration phase, and

^_ArcCO is a difference between a velocity of the motion system at an end of the deceleration phase and a velocity of the motion system at a beginning of the deceleration phase.

6. The method of claim 1 , further comprising determining at least one controller gain coefficient for the motion system based on the inertia.

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7. A system for estimating mechanical parameters of a motion system, comprising:

a memory;

a processor configured to execute computer-executable components stored on the memory, the computer-executable components comprising:

a torque command generator configured to generate a torque command signal that varies continuously over time during a testing sequence, wherein the testing sequence comprises an acceleration phase and a deceleration phase;

a velocity monitoring component configured to obtain velocity data representing a velocity of a motion system over time in response to the torque command signal; and

an inertia component configured to estimate an inertia of the motion system based at least in part on a product of an integral of the velocity data over the acceleration phase and an integral of the torque command signal over the deceleration phase.

8. (Cancelled)

9. The system of claim 7, wherein the torque command generator is further configured to control the torque command signal in accordance with a torque function u(c), where (t) is based on a set of predefined instructions associated with respective phases of the testing sequence, and wherein the respective phases are triggered in response to the velocity of the motion system reaching respective defined velocity checkpoint values.

10. The system of claim 7, wherein the inertia component is further configured to estimate the inertia as a function of v_e

where:

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u a«(t) is a portion of the torque command signal corresponding to the acceleration phase of the testing sequence,

vecc(t) is a portion of the velocity data corresponding to the acceleration phase,

u_AeA is a portion of the torque command signal corresponding to the deceleration phase of the testing sequence, and

v&cV) is a portion of the velocity data corresponding to the deceleration phase.

1 1 . The system of claim 10, wherein the inertia component is further configured to estimate the inertia based on:

where:

J is the inertia,

^Avcee ( ^{is a} difference between a velocity of the motion system at an end of the acceleration phase and a velocity of the motion system at a beginning of the acceleration phase, and

Av_dee (t) is a difference between a velocity of the motion system at an end of the deceleration phase and a velocity of the motion system at a beginning of the deceleration phase.

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12. The system of claim 10, further comprising a friction coefficient component configured to estimate a friction coefficient of the motion system based on:

_B _ A y_gc (/)ty_occ - Av_0CCE/_rfgc

where,

S is the friction coefficient,

Av_aee<*) is a difference between a velocity of the motion system at an end of the acceleration phase and a velocity of the motion system at a beginning of the acceleration phase, and

^Av_e.„_c(t) is a difference between a velocity of the motion system at an end of the deceleration phase and a velocity of the motion system at a beginning of the deceleration phase.

13. The system of claim 7, further comprising a tuning component configured to generate at least one controller gain coefficient as a function of the inertia.

14-20. (Cancelled)

21 . The method of claim 4, further comprising:

determining a friction coefficient of the motion system according to:

Δν_Λ,( ^ - Δν_οεε( ^ " where:

B is the friction coefficient,

&v„_Kf it) is a difference between a velocity of the motion system at an end of the acceleration phase and a velocity of the motion system at a beginning of the acceleration phase, and

74 Aw_d(IB(i) is a difference between a velocity of the motion system at an end of the deceleration phase and a velocity of the motion system at a beginning of the deceleration phase.

22. The system of claim 7, further comprising a friction coefficient component configured to estimate a friction coefficient of the motion system based on the torque command signal and the velocity data.