JPH02124422A - Absolute position operating circuit of incremental encoder - Google Patents

Abstract

PURPOSE:To follow a previous absolute position by maintaining electric power supply to an incremental encoder, a signal receiving circuit, an absolute position circuit, etc. by a charging power supply circuit at the time of system power failure. CONSTITUTION:A signal receiving circuit 1 receives a two-phase output pulse from an incremental encoder (IE) 200, distinguishes its direction and outputs an updown pulse signal. Then, an absolute position circuit 2 counts the updown signal of the circuit 1 and outputs an absolute position signal with a pulse signal from an adjacent switch 300. A disconnection detecting circuit 3 detects disconnection of a signal cable of the IE 200 from the output pulse of the circuit 1. A disconnection occurrence storing circuit 4 stores occurrence of disconnection by the disconnection detecting signal of the circuit 3. A charging power supply circuit 5 supplies power to the IE 200 and the circuits 1 to 4 from a battery respectively even at the time of system power failure, thereby enabling the previous absolute position or a position which has moved during disconnection to be followed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an absolute position calculation circuit for an incremental encoder that is applied to signal processing of an incremental encoder such as a device having positioning control.

[Prior Art] FIG. 3 is a block diagram showing the configuration of an absolute position calculation circuit of a conventional incremental encoder, in which 100 is an absolute position calculation circuit of an incremental encoder, 200 is an incremental encoder, and 300 is a specific rotation of the incremental encoder. It is a proximity switch that emits a pulse signal at the position. The absolute position calculation circuit 100 of the incremental encoder includes a signal receiving circuit 1 that receives a pulse train signal transmitted by the incremental encoder 200, and a signal receiving circuit 1 that counts output pulses from the signal receiving circuit 1, and counts output pulses from the proximity switch 300. Accordingly, the present invention includes an absolute position circuit 2 that generates an absolute position signal of the incremental encoder 200, and a disconnection detection circuit 3 that detects a signal disconnection state of the incremental encoder 200 based on a signal from the signal receiving circuit 1. .

[Problems to be Solved by the Invention] The system power supply S source of the conventional example is connected to the incremental encoder 200. The signal receiving circuit 1. The absolute position circuit 2. Although power is supplied to each of the disconnection detection circuits 3, when the system power is turned off, absolute position information is lost due to power loss. For this reason, conventionally, absolute encoders have been used that can follow the original absolute position or the position that was moved during the power outage as long as the power is restored even in the event of a power outage. However, absolute encoders have the drawbacks of high cost and inability to improve resolution.

Therefore, it would be very useful industrially if the disadvantage of losing absolute position information when the system fIi is turned off could be eliminated by using an incremental encoder that can improve resolution at low cost. An object of the present invention is to provide an absolute position calculation circuit for an incremental encoder that can solve the problem of following absolute position information when the system power is turned off.

[Means for Solving the Problems] 1; An absolute position calculation circuit for an incremental encoder according to the present invention includes a signal receiving circuit of the incremental encoder, and counts output pulses of the signal receiving circuit, and calculates a specific rotation of the incremental encoder. an absolute position circuit having a function of correcting to a predetermined value using a pulse signal transmitted at a position; a disconnection detection circuit that detects a disconnection of the signal cable of the incremental encoder from the output pulse of the signal receiving circuit; and the disconnection detection circuit. A disconnection occurrence memory circuit that stores the occurrence of a disconnection in response to a circuit disconnection detection signal, and a disconnection occurrence memory circuit that is charged from the system power supply and even when the system power supply is turned off, the incremental encoder, the signal receiving circuit, the absolute position circuit, and the disconnection detection circuit, respectively. It is characterized by comprising a charging power supply circuit that supplies power to the circuit and the disconnection occurrence storage circuit.

That is, in the present invention, as a technical means to solve the problem, power is maintained to be supplied to the incremental encoder, signal receiving circuit, absolute position circuit, disconnection detection circuit, and disconnection occurrence storage circuit even when the system power is turned off. Even if the charging power supply circuit is able to maintain power supply, if the cable between the incremental encoder's absolute position calculation circuit and the incremental encoder is disconnected, or if the connector is disconnected, the original absolute position, or
It is impossible to follow the position that has moved during the disconnection, and the accuracy of the absolute position signal that is the output of the absolute position circuit cannot be guaranteed, so only in this case should you return to the origin or reset the absolute position. Unavoidably, a disconnection occurrence storage circuit is provided to determine this.

[Function] According to the present invention, for example, in FIG. 1, the absolute position calculation circuit 1000 of the incremental encoder receives two-phase output pulses from the incremental encoder 200, discriminates the direction, and outputs an up-down pulse signal. A signal receiving circuit 1 and an absolute position having a function of counting up and down pulse signals of the signal receiving circuit 1 and correcting it to a predetermined value by a pulse signal from the proximity switch 300, and outputting an absolute position signal. a disconnection detection circuit 3 that detects a disconnection of the signal cable of the incremental encoder 200 from the output pulse of the signal receiving circuit 1; and a disconnection occurrence memory circuit 4 that stores the occurrence of a disconnection based on the disconnection detection signal of the disconnection detection circuit 3. A battery is charged with electrical energy from a system power supply, and even when the system power supply is turned off, the incremental encoder 200, the signal receiving circuit 1, the absolute position circuit 2, the disconnection detection circuit 3, and the Since it is comprised of a charging power supply circuit 5 that supplies power to each of the disconnection occurrence storage circuits 4, even when the system power is turned off, power supply to each of the circuits is maintained and the absolute position can be followed. Furthermore, by providing a disconnection occurrence storage circuit that determines whether the cable is disconnected or the like, for example, when a disconnection is determined, recovery work such as returning to the origin or resetting the absolute position can be started.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing details of the embodiment of the present invention shown in FIG.
1000 is an absolute position calculation circuit of an incremental encoder according to the present invention. Signal receiving circuit 1 is receiving circuit 1
1 and a direction determining circuit 21. The receiving circuit 11 receives a two-phase differential pulse signal from the incremental encoder 200 and generates a two-phase pulse signal. The direction determining circuit 12 determines the phase state of the two-phase pulse signal from the receiving circuit 11, determines the shaft rotation direction of the incremental encoder 200, and generates an up signal corresponding to the shaft rotation direction.

Generate a down signal pulse signal. The absolute position circuit 2 includes an up/down counter 21 and a preset value setter 22. The preset setting 122 is a setting device that presets the absolute position indicated by the specific rotational position of the incremental encoder 200.

The set value of the preset value setter 22 is connected to the preset input terminal of the up/down counter 21. The up/down counter 21 counts up and down pulse signals from the receiving circuit 1, and calculates and outputs the absolute rotational position of the shaft of the incremental encoder ZGO. Further, when the shaft of the incremental encoder 200 reaches a specific rotational position, the proximity switch 300
transmits a pulse signal, the pulse signal is input to the preset command terminal of the up-down counter 21, the set value of the preset value setter 22 is replaced with the counter value of the up-down counter 21, and the absolute position is corrected. will be accomplished.

The disconnection detection circuit 3 consists of two exclusive OR gates 31 and 32 and a Nant gate 33. The two exclusive OR gates 31 and 32 are connected to the incremental encoder two-phase differential signals A-X and B-H in the signal receiving circuit 1, respectively. Here, the two-phase differential signals A-1 and B-4 are "0"-1 during normal operation.
Only combinations of "1" and "0" are taken, so the outputs of the two exclusive OR gates 31 and 32 are 4111, and as a result, the output of the Nant gate 33 is "0".Here, the incremental encoder 200 When a disconnection occurs in the signal line, the two-phase differential signal becomes “1”-
A combination of “1” and “0°-”0° will occur, resulting in two exclusive or gates 3
At least one of the outputs of 1.32 becomes “1”,
Therefore, the output of the Nant gate 33 becomes "1".

The disconnection occurrence storage circuit 4 consists of an R-S flip-flop 4I, the set input of which is connected to the output of the Nandt gate 33 in the disconnection detection circuit 3. Therefore, if a - degree disconnection is detected, that state is determined by the R-S flip-flop 41.
The storage result is output to the system as a disconnection storage signal.

The charging power supply circuit 5 includes a diode 51 and a charging battery 52.
It consists of A charging battery 52 is charged with electrical energy from the system power supply and is used to charge the incremental encoder 200. The signal receiving circuit 1゜The absolute position circuit 2
．． Power is supplied to the disconnection detection circuit 3 and the disconnection occurrence storage circuit 4, respectively. The diode 51 serves to prevent electrical energy from flowing backward from the charging battery 52 to the system power source.

[Effects of the Invention] As described above, according to the present invention, even when the system power is cut off, the charging power supply circuit can supply power to the incremental encoder, signal receiving circuit, absolute position circuit, disconnection detection circuit, and disconnection occurrence storage circuit. is maintained, so it is possible to follow the original absolute position or the position that moved during the disconnection. In addition, if a cable break between the incremental encoder absolute position calculation circuit and the incremental encoder occurs, or a break occurs due to connector removal, the state is stored in the break memory circuit, so the absolute position can be determined by determining the break memory signal. It becomes possible to begin information recovery work.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention;
FIG. 2 is a diagram showing the detailed configuration of the embodiment shown in FIG. 1, and FIG. 3 is a block diagram showing the configuration of a conventional example. 4... Disconnection occurrence memory circuit, 5... Charging power supply circuit.

Claims (1)

[Claims] a signal receiving circuit of an incremental encoder; and an absolute position circuit having a function of counting output pulses of the signal receiving circuit and correcting them to a predetermined value using a pulse signal transmitted at a specific rotational position of the incremental encoder; a disconnection detection circuit that detects disconnection of the signal cable of the incremental encoder from the output pulse of the signal receiving circuit; a disconnection occurrence storage circuit that stores the occurrence of disconnection according to the disconnection detection signal of the disconnection detection circuit; and a disconnection occurrence memory circuit that is charged from the system power supply; and a charging power supply circuit that supplies power to the incremental encoder, the signal receiving circuit, the absolute position circuit, the disconnection detection circuit, and the disconnection occurrence storage circuit even when the system power is turned off. Absolute position calculation circuit for incremental encoder.