US 11,852,575 B2
State determination apparatus, state determination method, and storage medium
Yuki Kawamuro, Ueda (JP); Akihiro Shioiri, Ueda (JP); and Naoto Nakayama, Ueda (JP)
Assigned to HIOKI E.E. CORPORATION, Ueda (JP)
Filed by HIOKI E.E. CORPORATION, Ueda (JP)
Filed on Aug. 4, 2021, as Appl. No. 17/393,948.
Claims priority of application No. 2020-133419 (JP), filed on Aug. 5, 2020.
Prior Publication US 2022/0042897 A1, Feb. 10, 2022
Int. Cl. G01N 15/04 (2006.01); G01N 27/07 (2006.01); G01N 27/22 (2006.01); H01M 10/0525 (2010.01)
CPC G01N 15/04 (2013.01) [G01N 27/07 (2013.01); G01N 27/228 (2013.01); H01M 10/0525 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A state determination apparatus comprising:
electrodes configured to apply an AC signal to a mixture, wherein the mixture is to be used as a positive electrode or a negative electrode, wherein the mixture includes a liquid and an insoluble solid matter mixed in the liquid;
a measurement unit configured to measure an impedance of the mixture for every frequency of the AC signal based on a response signal flowing through the mixture when the AC signal is applied to the mixture by the electrodes;
a setting unit configured to set an equivalent circuit corresponding to the mixture, wherein the equivalent circuit includes a series circuit that is obtained by serially connecting one or a plurality of first parallel circuit(s) based on element(s) corresponding to an internal resistance component of the solid matter and one or a plurality of second parallel circuit(s) based on element(s) corresponding to a contact resistance component between the solid matter;
a calculating unit configured to calculate a parameter of the first and second parallel circuits by executing an equivalent circuit analysis for approximating impedance of the equivalent circuit to the impedance of the mixture; and
a derivation unit configured to derive an index for specifying the state of the mixture based on the parameter of the first and second parallel circuits, wherein the index specifies a homogeneity of the mixture.