Displacement detecting apparatus, torque detecting apparatus, robot apparatus and displacement detecting method

A torque detecting apparatus which detects a force of deforming an elastic body, by a displacement detecting apparatus, through a quantity of a rotational displacement of the elastic body against a fixed member arranged in the vicinity of the elastic body, which is formed by deformation of the elastic body, wherein the displacement detecting apparatus comprises:

• a scale which has an optical pattern of a lattice arrangement;
• a detecting head which has light-receiving elements, which detect the optical pattern of the scale;
• and
• a controlling apparatus which acquires a rotational displacement quantity of the scale with respect to the detecting head, based on a change of outputs of the detecting head,
• wherein the rotational displacement quantity of the scale with respect to the detecting head is determined using a first displacement quantity calculated based on a total light quantities that are output from the detecting head, and a second displacement quantity calculated based on an incremental displacement signal that is output from the detecting head, and
• wherein any one of the scale and the detecting head is fixed to the elastic body, the other is fixed to the fixed member so as to face any one of the scale and the detecting head fixed to the elastic body, and the torque detecting apparatus detects a force that is applied to the elastic body through the quantity of the rotational displacement between the scale and the detecting head, which the displacement detecting apparatus acquires.

A robot apparatus comprising:

• a robot arm provided with a torque detecting apparatus at a joint or a driving unit of a robot hand;
• a controlling unit configured to execute a robot controlling to control an operation of the robot arm, based on a driving torque of the driving unit detected by the torque detecting apparatus,
• wherein the torque detecting apparatus detects a force of deforming an elastic body, by a displacement detecting apparatus, through a quantity of a rotational displacement of the elastic body against a fixed member arranged in the vicinity of the elastic body, which is formed by deformation of the elastic body, wherein the displacement detecting apparatus comprises:
• a scale which has an optical pattern of a lattice arrangement;
• a detecting head which has light-receiving elements, which detect the optical pattern of the scale;
• and
• a controlling apparatus which acquires a rotational displacement quantity of the scale with respect to the detecting head, based on a change of outputs of the detecting head,
• wherein the rotational displacement quantity of the scale with respect to the detecting head is determined using a first displacement quantity calculated based on a total light quantities that are output from the detecting head, and a second displacement quantity calculated based on an incremental displacement signal that is output from the detecting head, and
• wherein any one of the scale and the detecting head is fixed to the elastic body, the other is fixed to the fixed member so as to face any one of the scale and the detecting head fixed to the elastic body, and the torque detecting apparatus detects a force that is applied to the elastic body through the rotational displacement quantity of the scale with respect to the detecting head, which the displacement detecting apparatus acquires.

A non-transitory computer readable recording medium storing a controlling program of a robot apparatus, the robot apparatus comprising:

• a robot arm provided with a torque detecting apparatus at a joint or a driving unit of a robot hand;
• and
• a controlling unit configured to execute a robot controlling to control an operation of the robot arm, based on a driving torque of the driving unit detected by the torque detecting apparatus, wherein the torque detecting apparatus detects a force of deforming an elastic body, by a displacement detecting apparatus, through a quantity of a relative rotational displacement of the elastic body against a fixed member arranged in the vicinity of the elastic body, which is formed by deformation of the elastic body, wherein the displacement detecting apparatus comprises:
• a scale which has an optical pattern of a lattice arrangement;
• a detecting head which has light-receiving elements, which detect the optical pattern of the scale;
• and
• a controlling apparatus which acquires a rotational displacement quantity of the scale with respect to the detecting head, based on a change of outputs of the detecting head, wherein any one of the scale and the detecting head is fixed to the elastic body, the other is fixed to the fixed member so as to face any one of the scale and the detecting head fixed to the elastic body, and the torque detecting apparatus detects a force that is applied to the elastic body through the rotational displacement quantity of the scale with respect to the detecting head, the program comprising code to execute:
• a first acquiring of acquiring by the controlling apparatus, a first displacement quantity calculated based on a total light quantities that are output from the detecting head;
• a second acquiring of acquiring, by the controlling apparatus, a second displacement quantity calculated based on an incremental displacement signal that is output from the detecting head;
• and
• a displacement detecting, by the controlling apparatus, of using the first displacement quantity and the second displacement quantity, to acquire the rotational displacement quantity of the scale with respect to the detecting head.

A displacement detecting method, executed by a displacement detecting apparatus, the displacement detecting apparatus comprising:

• a scale which has an optical pattern of a lattice arrangement;
• a detecting head which has light-receiving elements, which detect the optical pattern of the scale;
• and
• a controlling apparatus which acquires a rotational displacement quantity of the scale with respect to the detecting head, based on a change of outputs of the detecting head,
• wherein the method comprises:
• a first acquiring of acquiring by the controlling apparatus, a first displacement quantity calculated based on a total light quantities that are output from the detecting head;
• a second acquiring of acquiring, by the controlling apparatus, a second displacement quantity calculated based on an incremental displacement signal that is output from the detecting head;
• and
• a displacement detecting, by the controlling apparatus, of using the first displacement quantity and the second displacement quantity, to acquire the rotational displacement quantity of the scale with respect to the detecting head.

A displacement detecting apparatus comprising:

• a scale having an optical pattern of a lattice arrangement;
• and
• a detecting head having light-receiving elements which detect the optical pattern of the scale,
• wherein a direction of the lattice arrangement of the optical pattern of the scale is arranged so as to incline against a tangential direction to a direction of rotating the scale with respect to the detecting head, and
• wherein a direction of the arrangement of the light-receiving elements is arranged so as to be along the tangential direction to the direction of rotating the scale with respect to the detecting head.

A displacement detecting apparatus comprising:

• a scale having an optical pattern of a lattice arrangement;
• and
• a detecting head having light-receiving elements which detect the optical pattern of the scale,
• wherein a direction of the arrangement of the light-receiving elements is arranged so as to incline against a tangential direction to a direction of rotating the scale with respect to the detecting head, and
• wherein a direction of the lattice arrangement of the optical pattern of the scale is arranged so as to be along the tangential direction to the direction of rotating the scale with respect to the detecting head.