Wiper control device

A wiper control device comprising:

• an acquisition unit configured to acquire a value related to a current flowing through a wiper motor that drives a wiper configured to reciprocate between a first position and a second position and that includes a first terminal to which an electric power is supplied to rotate the wiper motor at a first speed and a second terminal to which an electric power is supplied to rotate the wiper motor at a second speed slower than the first speed;
• an estimation unit configured to estimate a wiper angle, which is a rotation angle of the wiper, based on a current ripple in the current flowing through the wiper motor, the current ripple having a periodicity corresponding to driving of the wiper motor;
• a first element configured to cause the current to flow through the wiper motor via the first terminal to rotate the wiper motor when the first element is turned on;
• a second element configured to cause the current to flow through the wiper motor via the second terminal to rotate the wiper motor when the second element is turned on;
• and
• a drive unit configured to turn on or off the first element and the second element, wherein
• the wiper angle is denoted as θw, θw=θmax when the wiper is at the second position, θw=2×θmax when the wiper is at the first position, and a predetermined angle is denoted as A, and
• the drive unit is further configured to:
• turn the first element from on to off to stop supplying the electric power to the first terminal, and keep the second element off to continue stopping supply of the electric power to the second terminal, when the first element is on and θw satisfies either (i) θmax−Δ≤θw<θmax or (ii) 2×θmax−Δ≤θw<2×θmax, and
• turn the first element from off to on to supply the electric power to the first terminal, and keep the second element off to continue stopping supply of the electric power to the second terminal, when (i) θw changes to θmax from a state satisfying θmax−Δ≤θw<θmax or (ii) when θw changes to 2×θmax from a state satisfying 2×θmax−Δ≤θw<2×θmax.