Robot with a flexible board having reduced noise leakage
A robot includes a driving unit, a flexible board including a power line that transmits electric power to the driving unit, and a choke coil connected to the power line. A band rejection filter is formed by parasitic capacitance, which is formed by the electric line, and the choke coil.
1. A robot comprising:
a plurality of arms that are serially connected to each other via a plurality of joints, the plurality of arms including a distal end arm that is located at a distal end of the plurality of arms;
a motor configured to drive the distal end arm, the motor being provided in the distal end arm;
a flexible board provided in one of the plurality of arms, the flexible board being connected to the motor, the flexible board including a board power line, a metal conductor, and an insulator, the board power line transmitting electric power to the motor so as to drive the distal end arm, the metal conductor having a ground potential, the insulator being provided between the board power line and the metal conductor;
a cable including a drive power line, the cable being connected to the flexible board via a relay, the cable being provided in the plurality of arms, the cable extending from a proximal end of the plurality of arms so that a cable end of the cable being spaced apart from the proximal end of the plurality of arms; and
a controller that is separately provided from the plurality of arms, the controller being configured with a power conversion circuit and a choke coil, the cable end being connected to the controller, the power conversion circuit converting the electric power by a switching element so as to transmit the electric power to the motor via the drive power line in the cable, the relay, and the board power line in the flexible board,
wherein a band rejection filter is formed by parasitic capacitance and the choke coil, and
the parasitic capacitance is formed by the board power line in the flexible board.
2. The robot according to claim 1 , wherein
the motor is driven by a polyphase alternating current, and
the flexible board includes a plurality of the board power lines for transmitting electric powers in respective phases of the polyphase alternating current.
3. The robot according to claim 2 , wherein
the choke coil is connected in series between a generation source for the polyphase alternating current and the board power line in the flexible board.
4. The robot according to claim 2 , wherein
a generation source includes the power conversion circuit, and
the band rejection filter is configured to reject a band including a peak frequency of switching noise in the power conversion circuit.
5. The robot according to claim 1 , wherein
the choke coil is a normal mode choke coil, and
the choke coil and the power conversion circuit are mounted on a same substrate.
6. The robot according to claim 1 , further comprising:
a wire at the ground potential,
wherein the wire is disposed side by side with the board power line.
7. The robot according to claim 1 ,
wherein the cable is provided entirely inside all of the plurality of arms.