KinematicPTP2

Move as fast as possible from start to end position within given kinematic constraints with output signals q, qd=der(q), qdd=der(qd)

    KinematicPTP2

Library

Modelica/Blocks/Sources

Description

The goal is to move as fast as possible from start position q_beginto end position q_endunder given kinematical constraints. The positions can be translational orrotational definitions (i.e., q_begin/q_end is given). In robotics such a movement is called PTP (Point-To-Point).This source block generates the position q(t), thespeed qd(t) = der(q), and the acceleration qdd = der(qd)as output. The signals are constructed in such a way that it is not possibleto move faster, given the maximally allowed velocity qd_max andthe maximally allowed acceleration qdd_max:

KinematicPTP2.png

If vectors q_begin/q_end have more than 1 element,the output vectors are constructed such that all signalsare in the same periods in the acceleration, constant velocityand deceleration phase. This means that only one of the signalsis at its limits whereas the others are synchronized in such a waythat the end point is reached at the same time instant.

This element is useful to generate a reference signal for a controllerwhich controls, e.g., a drive train, or to drivea flange according to a given acceleration.

Parameters

KinematicPTP2_0

NameLabelDescriptionData TypeValid Values

mo_q_begin

q_begin

Start position

Vector

mo_q_end

q_end

End position

Vector

mo_qd_max

qd_max

Maximum velocities der(q)

Vector

mo_qdd_max

qdd_max

Maximum accelerations der(qd)

Vector

mo_startTime

startTime

Time instant at which movement starts

Scalar

mo_nout

nout

Number of output signals (= dimension of q, qd, qdd, moving)

Scalar

mo_p_q_begin

p_q_begin

Vector

mo_p_q_end

p_q_end

Vector

mo_p_qd_max

p_qd_max

Vector

mo_p_qdd_max

p_qdd_max

Vector

mo_p_deltaq

p_deltaq

Vector

KinematicPTP2_1

NameLabelDescriptionData TypeValid Values

mo__nmodifiers

Number of Modifiers

Specifies the number of modifiers

Number

mo__modifiers

Modifiers

Add new modifier

Structure

mo__modifiers/varname

Variable name

Cell of strings

'endTime'
'motion_ref'
'sd_max_inv'
'sdd_max_inv'
'sd_max'
'sdd_max'
'sdd'
'aux1'
'aux2'
'Ta1'
'Ta2'
'Tv'
'Te'
'noWphase'
'Ta1s'
'Ta2s'
'Tvs'
'Tes'
'sd_max2'
's1'
's2'
's3'
's'
'sd'

mo__modifiers/attribute

Attribute

Cell of strings

'start'
'fixed'

mo__modifiers/value

Value

Ports

NameTypeDescriptionIO TypeNumber

q

implicit

Reference position of path planning

output

1

qd

implicit

Reference speed of path planning

output

2

qdd

implicit

Reference acceleration of path planning

output

3

moving

implicit

= true, if end position not yet reached; = false, if end position reached or axis is completely at rest

output

4

See Also