EP0176173A2
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EP
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Sensor for sensing three orthogonal forces and three orthogonal moments
Assignee: Toshiba Corp
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Filing: 1985-06-18
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Granted: —
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Expires: 2005-06-18
Abstract
Abstract A sensor includes six strain gages (21, 22, 23, 24, 25, 26) attached to a detection section (12) equidistantly in the circumferential direction of the detection section. The strain gages are of an orthogonal two-gage type and, in an orthogonal coordinates system (X, Y, Z) with the axial direction of the detection section as the Z-axis, are arranged such that their strain detection direction is inclined at an angle a of 0< a < 45° from the Z-axis. A linear relation given by the following matrix expression exists between outputs ε 1 , ε 2 , ε 3 , ε 4 , ε 5 , ε 6 of the six strain gages and six force components F x , F y , F z , M x , My, M z : (ε 1 , ε 2 , ε 3 , ε 4 , ε 5 , ε 6 ) T = [B]. (F x , F y , F z , M x , My, M z ) T where [B] denotes a matrix of coefficient and can be initially found by applying known force components to the detection section and calibrating. It is therefore possible to calculate force components from this matrix expression.
Inventors
- 👤 Shoichi C/O Patent Division Iikura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 07:14
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/20; G01L1/22; G01L1/2206; G01L1/2218; G01L5/00; G01L5/16; G01L5/161; G01L5/1627; G01L5/22; G01L5/226
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
123 words
A sensor for sensing three orthogonal forces and three orthogonal moments, comprising: a detection section (12) which produces strain when a load is applied to the detection section; and strain gages (21, 22, 23, 24, 25, 26) arranged at the detection section; characterized in that the detection section is of a thin walled cylindrical shape, the strain gages are six and spaced in the circumferential direction of the detection section, ano an arithmetic device (30) calculates, from outputs ε 1 , E2' ε 3 , ε 4 , ε 5 and ε 6 of the six strain gages, six force components F X , F y, F Z , M X , My and M Z which are applied to the detection section.
Claim 2
Dependent Claim
123 words
A sensor for sensing three orthogonal forces and three orthogonal moments, comprising: a detection section (12) which produces strain when a load is applied to the detection section; and strain gages (21, 22, 23, 24, 25, 26) arranged at the detection section; characterized in that the detection section is of a thin walled cylindrical shape, the strain gages are six and spaced in the circumferential direction of the detection section, ano an arithmetic device (30) calculates, from outputs ε 1 , E2' ε 3 , ε 4 , ε 5 and ε 6 of the six strain gages, six force components F X , F y, F Z , M X , My and M Z which are applied to the detection section.
Claim 3
Dependent Claim
108 words
A sensor according to claim 1, characterized in that, in an orthogonal coordinates system (X, Y, Z) where the Z-axis is in the axial direction of said detection section and X- and Y-axes are perpendicular to each other and to the Z-axis, force components F X , F Y , F Z , M x , M Y and M Z are such that said force components F X , F Y and F Z are forces acting in the X-, Y- and Z-axis directions and that the force components M XI M Y and M Z are moments acting around the X-, Y- and Z-axis moments, respectively.
Claim 4
Dependent Claim
27 words
A sensor according to claim 2, characterized in that said six strain gages (21, 22, 23, 24, 25, 26) are arranged equidistantly on said detection section (12).
Claim 5
Dependent Claim
111 words
A sensor according to claim 2, characterized in that three strain gages (21, 23, 25) are of an orthogonal two-gage type, each of which have their strain direction 45°-inclined with respect to the Z-axis and the remaining strain gages (22, 24, 26) are arranged in a direction parallel to the Z-axis; and only a shear stress τ θZ is found from the outputs ε 1 , ε 3 and ε 5 of the strain gages in the 45°-inclined direction and only a normal stress σ Z in the Z-axis direction is found from the outputs ε 2 , ε 4 and ε 6 of the strain gages in the Z-axis direction.
Claim 6
Dependent Claim
53 words
A sensor according to claim 4, characterized in that said arithmetic calculator (30) calculates six force components from equations (1) to (5) below: where S and Z: the lateral cross-sectional area and section modulus of the cylindrical portion of said detection section; and L: a constant showing the position of the strain gage.
Claim 7
Dependent Claim
74 words
A sensor according to claim 5, characterized in that said arithmetic calculator (30) calculates three force components F XI F Y and M Z from three measured values for the shear stress τ θZ on the basis of said equations (2) to (5) and calculates the remaining force components F X , M X and M Y from three measured values for the normal stress σ Z on the basis of the equation (1).
Claim 8
Dependent Claim
20 words
A sensor according to claim 2, characterized in that each of the strain gages is of an orthogonal two-gage type.
Claim 9
Dependent Claim
45 words
A sensor according to claim 2, characterizeo in that the respective strain gages (21, 22, 23, 24, 25, 26) are of a four-gage type and are arranged two on the inner periphery surface and two on the outer periphery surface of said detection section (12)..
Claim 10
Dependent Claim
56 words
A sensor according to claim 2, characterized in that the respective strain gages (21, 22, 23, 24, 25, 26) are of an orthogonal two-gage type and are arranged on the detection section (12) such that their strain detection direction is inclined at an angle a of 0 < a < 45° with respect to the Z-axis.
Claim 11
Dependent Claim
102 words
A sensor according to claim 9, characterized in that the output e(e) of the respective strain gage (21, 22, 23, 24, 25, 26) is obtained as a difference between two outputs E a(e) and eb(e) ana the outputs ε 1 , ε 2 , ε 3 , ε 4 , ε 5 and E6 of the six strain gages (e = θ 1 , θ 2 , θ 3 , θ 4 , θ 5 , θ 6 ) are found through the calculation of the following matrix equation: where [B]: a (6 x 6) matrix of coefficient T: a transposed vector.
Claim 12
Dependent Claim
41 words
A sensor according to claim 10, characterized in that said matrix of coefficient is found based on the output of the respective gages (21, 22, 23, 24, 25, 26) through the application of known force components to the detection section (12).
References Cited (Backward Citations)
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