An angle detection mechanism to detect a rotation angle of a rotation body includes a first detection unit to cause a first output value to constantly change in response to an angle change of the rotation body in the entire region of a specific rotation range and to set a change quantity of the first output value relative to the angle change in a first rotation region of the specific rotation range to be greater than a change quantity in a non-first rotation region, and a second detection unit to cause a second output value to constantly change in response to an angle change and to set a change quantity of the second output value in a second rotation region including a rotation region different from the first rotation region to be greater than a change quantity in a non-second rotation region.

A grip, a magnet 140, and a substrate 150 are included. The grip is rotatable between positions where a throttle is fully closed and a position where the throttle is fully open with a rotating shaft as a center. The magnet 140 rotates integrally with the grip. The substrate 150 includes a plurality of Hall elements 165 and 175, and is fixed to face the magnet 140. The plurality of Hall elements 165 and 175 are disposed in such a way that magnetic flux densities different from each other are respectively applied to the plurality of Hall elements 165 and 175 when an external magnetic field acts in a state where the grip is located in the position where the throttle is fully closed.

A throttle valve abnormality determination device includes a permission/rejection determination unit configured to determine whether or not to permit a sticking determination of a throttle valve. The determination unit is configured to prohibit the sticking determination if a first temperature, which is a temperature in a passage through which intake air flows, is less than or equal to a freezing temperature at which the throttle valve may be frozen when an engine is started and, after prohibiting the sticking determination, permit the sticking determination if an integrated value of a heat amount conversion value based on a second temperature, which is a temperature in the passage, and an intake air amount exceeds a threshold value when the second temperature is greater than or equal to a de-freezing temperature at which a frozen portion of the throttle valve is de-frozen.

Disclosed is a verification system including a throttle actuation verification system. The verification system may include one or more sensors positioned at a location that will receive a force applied by an operator when a throttle lever is engaged or loaded for the intention to be actuated by the operator. A signal from the sensor is compared to a throttle position.

An engine kill switch and a throttle lever position sensor switch both remote from the engine and connected by a pair of wires to a microcontroller for controlling a spark initiated combustion of an air-fuel mixture in a cylinder of the engine. The switches may be received in the same housing and mounted in an operator handle housing of a hand held power tool.

A method for controlling a position of an electronic throttle valve of an internal combustion engine is provided. The method includes determining a desired throttle valve position; determining a first feed forward signal based on a rate of change between a previous throttle valve position and the desired throttle valve position; and determining a second feed forward signal based on a comparison of the desired throttle valve position to a limp home position of the throttle valve, in which the throttle valve is biased open by a spring. A summation of the first and second feed forward signals is used to actuate the throttle valve. After the throttle valve has been actuated according to the first and second feed forward signals, the position of the throttle valve is controlled with a feedback controller to obtain the desired throttle valve position.

A Halbach array is formed from first to third magnets provided to a rotor. Of shortest straight-line distances (clearance distances) between the first to third magnets and a Hall element as facing the first to third magnets after moving relative to the first to third magnets, the shortest straight-line distance between the second magnet and the Hall element is set the longest. In other words, the second magnet is placed at a position offset from the first magnet. In addition, the second magnet may be offset from the third magnet.

A flow measuring device includes a housing including a bypass passage and a flow sensing chip located in the bypass passage and including a sensing surface portion. A throttle portion that is a part of a flowing passage wall facing a sensing surface portion throttles a cross-sectional area of a bypass passage. A position where the throttle portion starts is referred to as a start point position, and a position of the throttle portion where a distance between a gravity center of the sensing surface portion and the throttle portion is shortest is referred to as an end point position. The start point position and the end point position define an imagination line, and the imagination line and the flowing direction define an angle that is in a range from 0 degrees to 20 degrees.

An exhaust purification system includes a selective catalytic reduction (SCR) catalyst disposed at an exhaust system of an engine for using ammonia that is generated from urea water as a reducing agent to reduce NOx contained in exhaust gas, a device that injects urea water to the SCR catalyst, an inlet-side electrode that detects capacitance within the SCR catalyst at least from a vicinity of an inlet of the SCR catalyst to a vicinity of an intermediate section in an exhaust gas flowing direction, an outlet-side electrode that detects the capacitance within the SCR catalyst at least from the vicinity of the intermediate section to an outlet of the SCR catalyst in the exhaust gas flowing direction, and a calculation unit that calculates an ammonia adsorption amount within the SCR catalyst on a basis of the capacitances detected from the inlet-side and the outlet-side electrodes.

An engine assembly includes an intake manifold and a manifold absolute pressure sensor configured to generate a current measured manifold absolute pressure (MAP.sub.M) signal for the intake manifold. The assembly includes a throttle valve adjustable to control airflow to the intake manifold and a throttle position sensor configured to generate a current measured throttle position (TP.sub.M) signal. A controller is operatively connected to the throttle valve and the manifold absolute pressure sensor and has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a predicted manifold absolute pressure (MAP.sub.P). Execution of the instructions by the processor causes the controller to determine the predicted manifold absolute pressure (MAP.sub.P) based at least partially on a predicted throttle flow (TF.sub.P) and the current measured manifold absolute pressure (MAP.sub.M) signal.