CN106584460A - Vibration suppression method in walking of humanoid robot - Google Patents

Abstract

The invention a vibration suppression method in walking of a humanoid robot based on an input shaper. The method comprises the following steps: firstly collecting ZMP position step response signals by using a pelma six-dimensional force/moment sensor; then building a model of a process from a ZMP reference value to a ZMP practical value according to the ZMP position step response signals, constructing the input shaper according to the obtained model, and calculating time advance of a reference ZMP track according to the obtained model; and finally putting the obtained input shaper and the time advance link in a reference ZMP track generator, and applying the reference ZMP track generator to walking of the humanoid robot. Through the vibration suppression method, the vibration caused by a non-rigid connection rod system in walking is suppressed in a feedforward manner by modifying the reference ZMP track sent to a centroid track generator, so that the walking is more stable; compared with a method for suppressing vibration by feedback, the method can suppress the vibration after the vibration occurs and is free of risk of oscillation caused by overhigh closed-loop gain.

Description

A kind of vibration suppressing method in Humanoid Robot Based on Walking

Technical field

The present invention relates to the vibration suppressing method in robotics, more particularly to a kind of Humanoid Robot Based on Walking.

Background technology

Due to there is non-rigid characteristic in the push and pull system of anthropomorphic robot, anthropomorphic robot is in the process of walking often There is vibration.When vibrating excessive, the position of point of zero moment (Zero Momentum Point, hereinafter referred to as ZMP) may reach To the edge of support polygon, the danger toppled over is brought.Therefore, it is necessary to be brought by push and pull system is non-rigid in suppressing to walk Vibration.

Suppress the vibration in Humanoid Robot Based on Walking, mainly there is following two classes method at present.The first kind is to improve robot The rigidity of push and pull system.It is general by improvement Design of Mechanical Structure or next from the higher driving means of performance and transmission mechanism Realize.The design level that this kind of method is limited to implementer and the hardware condition having, and general cost is high, or can bring The drawbacks of weight increases.Equations of The Second Kind is that vibration is considered as into additional disturbance, and by feedback control the suppression to disturbing is realized.It is this kind of Method only has occurred and that and walking stability being generated the effect of just can start after adverse effect, and suppression action in vibration Itself may bring new vibration.

The content of the invention

Present invention aims to the deficiencies in the prior art, there is provided the vibration suppression in a kind of Humanoid Robot Based on Walking Method.

The purpose of the present invention is achieved through the following technical solutions：A kind of anthropomorphic robot based on input forming device Vibration suppressing method in walking, comprises the following steps that：

(1) using vola six-dimensional force/torque sensor collection ZMP positions phase step response signals；

(2) ZMP reference values are modeled to the process of ZMP actual values according to ZMP phase step response signals；

(3) according to the model for obtaining, input forming device is constructed；

(4) according to the model for obtaining, the Timing Advance with reference to ZMP tracks is calculated；

(5) after the input forming device for obtaining and time advance link being placed in reference to ZMP track creators, it is applied to imitate The walking of robot people.

Further, the step (1) is specially：Robot both feet are made to land, while amplitude is bipod center distance four The reference ZMP step signals of/mono- left and right directions, or an amplitude is the ginseng of the fore-and-aft direction of bipod length a quarter Examine ZMP step signals to be input in the centroid trajectory maker controlled based on preview, produce corresponding or so or fore-and-aft direction Barycenter translational motion, is measured during this on left and right or fore-and-aft direction using the six-dimensional force/torque sensor installed in vola Actual ZMP change in location track.

Further, the step (2) is specially：If defeated by actual ZMP is input to reference to ZMP on left and right or fore-and-aft direction Transmission function G (s) of the complex domain form of the process for going out is

Wherein, s is the Laplace transform operator of complex domain, and ζ is damped coefficient, and ω is nothing Damping nature frequency of oscillation.

Using the input-output data measured in step (1), using least square method or analytic method, model parameter is asked for ω and ζ；

Further, the step (3) is specially：The digital filter form that construction is made up of two pulses is entered as Shape device, amplitude A of two pulses₁And A₂Respectively

Wherein parameter K is defined as：

And the moment t of two pulses₁And t₂Respectively：

Further, the step (4) is specially：Equation of the numerical methods of solving with regard to time t：

In t>Solution t=T when 0₀, then T₀It is the Timing Advance with reference to the input of ZMP tracks, it is theoretical defeated under this lead Go out the integration minimum of ZMP tracks and the absolute value with reference to the error between ZMP tracks；

Further, the step (5) is specially：It is T by foregoing time span₀Time advance link and defeated Enter former to be inserted into after the reference ZMP track creators of left and right or fore-and-aft direction, the modification after the two links Reference ZMP tracks be input in centroid trajectory maker, you can produce cause left and right or fore-and-aft direction vibration it is repressed Motion.

The invention has the beneficial effects as follows, the present invention is sent to the reference ZMP tracks of centroid trajectory maker by modification, front Inhibit in walking by the non-rigid vibration for bringing of push and pull system to feedback so that walking is more stable.Compared to modification machinery knot The method that structure suppresses vibration, this method does not need extra cost.Method compared to being vibrated by feedback inhibition, this method is existed Vibration is just suppressed before occurring, and without the excessive risk for causing to vibrate of closed loop gain.

Description of the drawings

Fig. 1 is that the anthropomorphic robot walking movement for having used this method generates overall control block diagram, the part of dotted line inframe For the vibration suppression feedforward controller that this method is introduced.

Fig. 2 be using this method before left and right directions ZMP reference locus and actual path, wherein dotted line be reference locus, Solid line is actual measurement track.

Fig. 3 is the ZMP positions phase step response signals collected using vola six-dimensional force/torque sensor, and wherein dotted line is The reference step signal of centroid trajectory maker is input to, solid line is practical measurement signals.

Fig. 4 be using this method after left and right directions ZMP reference locus and actual path, wherein dotted line be reference locus, Solid line is actual measurement track.

Specific embodiment

Vibration suppressing method in a kind of Humanoid Robot Based on Walking based on input forming device of the present invention, concrete steps are such as Under：

1st, using vola six-dimensional force/torque sensor collection ZMP positions phase step response signals：

Make robot both feet land, at the same by an amplitude for bipod center distance a quarter left and right directions reference ZMP step signals, or amplitude is input to for the reference ZMP step signals of the fore-and-aft direction of bipod length a quarter and is based on In the centroid trajectory maker of preview control, the barycenter translational motion of corresponding left and right or fore-and-aft direction is produced, using being arranged on Six-dimensional force/the torque sensor in vola measures during this left and right or the actual ZMP change in location track on fore-and-aft direction.

2nd, ZMP reference values are modeled to the process of ZMP actual values according to ZMP phase step response signals：

If by the transmission letter of the complex domain form that the process that actual ZMP is exported is input to reference to ZMP on left and right or fore-and-aft direction Counting G (s) is

Wherein, s is the Laplace transform operator of complex domain, and ζ is damped coefficient, and ω is nothing Damping nature frequency of oscillation.

Using the input-output data measured in step (1), using least square method or analytic method, model parameter is asked for ω and ζ.

3rd, according to the model for obtaining, input forming device is constructed：

The input forming device of the digital filter form that construction is made up of two pulses, amplitude A of two pulses₁And A₂Point It is not：

Wherein parameter K is defined as：

And the moment t of two pulses₁And t₂Respectively：

4th, according to the model for obtaining, the Timing Advance with reference to ZMP tracks is calculated：

Equation of the numerical methods of solving with regard to time t：

In t>Solution t=T when 0₀, then T₀It is the Timing Advance with reference to the input of ZMP tracks, it is theoretical defeated under this lead Go out the integration minimum of ZMP tracks and the absolute value with reference to the error between ZMP tracks.

5th, after the input forming device for obtaining and time advance link being placed in reference to ZMP track creators, it is applied to imitate The walking of robot people：

It is T by foregoing time span₀Time advance link and input forming device be inserted into left and right or front and back To reference ZMP track creators after, the reference ZMP tracks changed after the two links are input to centroid trajectory In maker, you can produce the repressed motion of vibration for causing left and right or fore-and-aft direction.

The present invention is further expalined by the following examples.With in the method walking actual to anthropomorphic robot Vibration is suppressed, and experimental data is provided by Zhejiang University.Fig. 2 be using this method before robot ambulation experiment in right and left To ZMP trajectory measurement values, it can be seen that vibration result in the fluctuation of ZMP positions, have impact on the stability of walking.Fig. 3 It is to be operated by step (1), the left and right directions ZMP positions phase step response signals for collecting.As described in step (2), thus believe Number model parameter is recognized, obtain ω=11.0966rads^-1, ζ=0.2166.And then as described in step (3), try to achieve Two pulse amplitude A of input forming device₁=0.6676, A₂=0.3324, corresponding time t₁=0, t₂=0.29s.While root According to step (4), try to achieve ZMP reference locus and shift to an earlier date duration T₀=0.1334s.Time advance link and input forming device are pressed into step (5) it is described to be applied in robot control system, ZMP trajectory measurements value such as Fig. 4 institutes of left and right directions in the walking experiment for obtaining Show, it can be seen that vibration has obtained significant suppression.

Claims (6)

1. a kind of vibration suppressing method in Humanoid Robot Based on Walking based on input forming device, it is characterised in that concrete steps It is as follows：

(1) using vola six-dimensional force/torque sensor collection ZMP positions phase step response signals.

(2) ZMP reference values are modeled to the process of ZMP actual values according to ZMP phase step response signals.

(3) model obtained according to step 2, constructs input forming device.

(4) model obtained according to step 2, calculates the Timing Advance with reference to ZMP tracks.

(5) Timing Advance that the input forming device for obtaining step 3 and step 4 are obtained be placed in reference to ZMP track creators it Afterwards, it is applied to the walking of anthropomorphic robot.

2. according to claim 1 based on the vibration suppressing method in the Humanoid Robot Based on Walking of input forming device, its feature It is that the step (1) is specially：Robot both feet are made to land, while being bipod center distance a quarter by an amplitude Left and right directions reference ZMP step signals, or amplitude is the reference ZMP ranks of the fore-and-aft direction of bipod length a quarter Jump signal input produces the barycenter translation of corresponding left and right or fore-and-aft direction in the centroid trajectory maker based on preview control Motion, using the six-dimensional force/torque sensor installed in vola actual ZMP on left and right or fore-and-aft direction is measured during this Change in location track.

3. according to claim 1 based on the vibration suppressing method in the Humanoid Robot Based on Walking of input forming device, its feature It is that the step (2) is specially：If answering by the process that actual ZMP outputs are input to reference to ZMP on left and right or fore-and-aft direction Transmission function G (s) of domain form is：

Wherein, s is the Laplace transform operator of complex domain, and ζ is damped coefficient, and ω is undamped Natural frequency of oscillation

Using the input-output data measured in step (1), using least square method or analytic method, ask for model parameter ω and ζ。

4. according to claim 1 based on the vibration suppressing method in the Humanoid Robot Based on Walking of input forming device, its feature It is that the step (3) is specially：The input forming device of the digital filter form that construction is made up of two pulses, two arteries and veins Amplitude A of punching₁And A₂Respectively：

$\left\{\begin{array}{c}{A}_1=\frac{1}{1+K}\\ A_2=\frac{K}{1+K}\end{array}\right.$

Wherein parameter K is defined as：

$K=e^{-\mathrm{\ζ}\mathrm{\π}/\sqrt{1-{\mathrm{\ζ}}^2}};$

And the moment t of two pulses₁And t₂Respectively：

$\left\{\begin{array}{c}{t}_1=0\\ t_2=\frac{\mathrm{\π}}{\mathrm{\ω}\sqrt{1-{\mathrm{\ζ}}^2}}\end{array}\right..$

5. according to claim 1 based on the vibration suppressing method in the Humanoid Robot Based on Walking of input forming device, its feature It is that the step (4) is specially：Equation of the numerical methods of solving with regard to time t：

$\frac{1}{\sqrt{1-{\mathrm{\ζ}}^2}}{e}^{-\mathrm{\ζ}\mathrm{\ω}t}sin(\mathrm{\ω}\sqrt{1-{\mathrm{\ζ}}^2}t+{\cos }^{-1}\mathrm{\ζ})=\frac{1-K}{2}$

In t>Solution t=T when 0₀, then T₀It is the Timing Advance with reference to the input of ZMP tracks, under this lead, theory output ZMP tracks and the integration minimum of the absolute value with reference to the error between ZMP tracks.

6. according to claim 1 based on the vibration suppressing method in the Humanoid Robot Based on Walking of input forming device, its feature It is that the step (5) is specially：It is T by foregoing time span₀Time advance link and input forming device insertion To after the reference ZMP track creators of left and right or fore-and-aft direction, the reference ZMP tracks changed after the two links In being input to centroid trajectory maker, you can produce the repressed motion of vibration for causing left and right or fore-and-aft direction.