A method for encoding information includes specifying a digital value and providing a symbol (28, 70, 80, 90, 100) comprising a plurality of polygons (72, 82, 92, 94, 102) meeting at a common vertex (74, 84, 96, 98, 104) and having different, respective colors selected so as to encode the specified digital value.

There is provided an arc welding control method of alternating feeding of a welding wire between forward feeding and reverse feeding periodically according to a feeding rate pattern constituted of a forward feeding amplitude, a reverse feeding amplitude, a forward feeding period and a reverse feeding period, stored in correspondence to an average feeding rate setting value, and generating short-circuiting periods and arc periods to perform welding. An average feeding rate of the welding wire is detected, and at least one of the forward feeding amplitude, the reverse feeding amplitude, the forward feeding period or the reverse feeding period is changed so that the detected average feeding rate equals the average feeding rate setting value, thereby automatically correcting the feeding rate pattern.

There is provided an arc welding control method of alternating feeding of a welding wire between forward feeding and reverse feeding periodically according to a feeding rate pattern constituted of a forward feeding amplitude, a reverse feeding amplitude, a forward feeding period and a reverse feeding period, stored in correspondence to an average feeding rate setting value, and generating short-circuiting periods and arc periods to perform welding. An average feeding rate of the welding wire is detected, and at least one of the forward feeding amplitude, the reverse feeding amplitude, the forward feeding period or the reverse feeding period is changed so that the detected average feeding rate equals the average feeding rate setting value, thereby automatically correcting the feeding rate pattern.

The present invention improves the stability of welding conditions in a welding method that involves cyclically repeating forward feed and reverse feed of a welding wire. Provided is an arc welding control method involving cyclic repetition of forward feed and reverse feed of a welding wire at feed speed, generating short-circuit intervals and arc intervals, during which arc intervals, application of a first welding current is followed by application of a second welding current smaller than the first welding current, wherein the phase of the feed speed at the point in time of transition from an arc interval to a short-circuit interval is detected, and the value and/or the application duration of the first welding current is varied in accordance with the detected phase. In so doing, fluctuation of the phase of the feed speed due to outside disturbances during generation of short-circuiting can be minimized.

The present invention improves the stability of welding conditions in a welding method that involves cyclically repeating forward feed and reverse feed of a welding wire. Provided is an arc welding control method involving cyclic repetition of forward feed and reverse feed of a welding wire at feed speed, generating short-circuit intervals and arc intervals, during which arc intervals, application of a first welding current is followed by application of a second welding current smaller than the first welding current, wherein the phase of the feed speed at the point in time of transition from an arc interval to a short-circuit interval is detected, and the value and/or the application duration of the first welding current is varied in accordance with the detected phase. In so doing, fluctuation of the phase of the feed speed due to outside disturbances during generation of short-circuiting can be minimized.

In controlling an arc welding of consumable electrode type in which pulse welding and short-circuit welding alternately repeat, forward feeding and backward feeding of a welding electrode periodically repeat in a short-circuit welding period. The forward feeding of the welding electrode starts when a welding current is smaller than a base current immediately before a pulse period ends.

In controlling an arc welding of consumable electrode type in which pulse welding and short-circuit welding alternately repeat, forward feeding and backward feeding of a welding electrode periodically repeat in a short-circuit welding period. The forward feeding of the welding electrode starts when a welding current is smaller than a base current immediately before a pulse period ends.

There is provided an arc welding control method for performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly upon starting the welding. The forward feeding is continued during a transient welding period from a time point at which the welding wire comes in contact with a base material and conduction of welding current is started to a time point at which convergence on a steady welding period is performed. The transient welding period is terminated at the short-circuiting period. The forward/reverse feeding control is started from the reverse feeding period after the termination of the transient welding period.

There is provided an arc welding control method for performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly upon starting the welding. The forward feeding is continued during a transient welding period from a time point at which the welding wire comes in contact with a base material and conduction of welding current is started to a time point at which convergence on a steady welding period is performed. The transient welding period is terminated at the short-circuiting period. The forward/reverse feeding control is started from the reverse feeding period after the termination of the transient welding period.

Disclosed is a method for controlling arc welding where an arc is generated between a welding wire as a consumable electrode and an object to be welded. The method includes: keeping a wire feed speed at a predetermined constant speed in a steady-state welding period; and at a time point when welding termination is ordered, either switching the wire feed speed from the predetermined constant speed to a wire feed speed at which the welding wire is fed in alternating forward and backward directions, or decreasing the wire feed speed from the predetermined constant speed with time, and then switching the wire feed speed to the wire feed speed at which the welding wire is fed in alternating forward and backward directions at a time point when a predetermined time period has passed since when welding termination was ordered.