Wheel Speed Sensor

The Michigan Scientific Wheel Speed Sensor uses an integrated encoder, which is attached to a wheel plate and mounted on a customer wheel using collet lug adapters. It is commonly used for automotive testing and gathering data on wheel speed, vehicle speed, and distance traveled.

Features

  • Easy Installation
  • Encoder wheel speed sensor
  • Available with or without weatherproof seals
  • Circular connectors on stator and rotor
  • Sealed, corrosion resistant metal housing
  • Lightweight and compact
  • Used in
    • Speed Testing
    • Vehicle Brake Testing

Description

The Wheel Speed Sensor Assembly is used as rotation sensor mounted outboard of a vehicle wheel. The rotation sensor is used to measure rotational velocity, angular position, and direction of rotation. The assembly consists of electronics in a rugged housing, which is attached to a wheel plate and mounted on the customer wheel using collet lug extensions.The output signals generated by the sensor can be use to determine wheel speed, acceleration, distance, and vehicle speed.

The assembly is very rugged and has been designed to accept contacting rotary seals. Units ordered with these seals are completely weatherproof and can survive days of total submersion. For higher speeds in dry conditions, order units without the contacting rotary seals.

Applications

Like many of Michigan Scientific’s products, the Wheel Speed Sensor instrumentation package is designed to be used on a variety of vehicles in many different testing applications. It is the optimal tool for  determining how far a vehicle has traveled, how fast the vehicle or wheels are going, and how fast the vehicle is accelerating. The output signals from the Wheel Speed Sensor are used for analysis in acceleration and braking tests as well as ABS testing. This is crucial when determining the tractive contact a vehicle has with a surface during vehicle development. These systems are commonly used during autonomous and electric vehicle development and weather testing in standard customer vehicles. Having an accurate measurement of wheel speed and distance traveled is also important for mapping for vehicle GPS and navigation systems. Wheel Speed Sensors provide reliable measurements to aid in vehicle innovation.

Options

Encoder (E)

Rotation sensor choices E256, E360, E500, & E512: Four optical encoder resolutions are offered. Each of these encoder choices has 4 outputs. Outputs A and B are in quadrature (exactly 90° out of phase). Output I is an index pulse. Output A+B is the exclusive OR of A and B, which doubles the basic resolution of the encoder. The outputs, 0 to 5 volt pulses, can drive TTL loads. The encoders will operate from a +5 to +20 Vdc, 100 mA power supply. Temperature range is -40F to +212F. The encoders have metal code wheels and rugged electronics so they tolerate shock and vibration. They are also protected from incorrect wiring up to 20 volts. Accuracy of encoder systems is 0.25° (maximum cumulative error).

Resolver (R)

Rotation sensor choice R360: A resolver can be specified instead of an encoder. The resolver is an analog rotation sensor with two outputs labeled sine and cosine. The outputs can be passed through the same type of filters as strain gage or other analog sensor signals coming through the slip rings. Then the rotation signal will remain in phase with the sensor signals.
The resolver requires additional external electronics for excitation and for processing the outputs. A resolver is an absolute position sensor. Its’ angular position is known as soon as the excitation and electronics is turned on, an index pulse does not have to be located before the shaft position can be determined. Temperature range is -40F to +250F. Accuracy of the resolver is 0.25°.
System accuracy, which includes the electronics, is within 1°.

Tachometer (T)

Rotation sensor choices T256, T360, T500 & T512: Additional encoder electronics can be built into the encoder units. The electronics adds two analog outputs, a voltage proportional to shaft velocity (similar to a tachometer) and a voltage proportional to the angular position of the shaft. The analog outputs are easier to record than the digital encoder outputs, which require high sampling rates. Both analog outputs are updated at each pulse of encoder output A, so they are instantaneous, not average values. The encoder electronics will operate from a +8 to +18 Vdc, 200 mA power supply.
Temperature range is -40F to +185F.

Full scale for the angular position output is +10V for rotation in either direction.

Full scale for the velocity output is +10V for rotation in one direction and -10V for rotation in the opposite direction. Two velocity sensitivities and direction of rotation are usually programmed into each unit. Two pins in the stator connector are designated as option pins, through which the user selects 1 of 4 combinations. For example, units used on our torque wheels are normally programmed to output 10V at 1000 rpm with option pin #1 open. With option pin #1 grounded, full scale is 1800 rpm. Option pin #2 sets the polarity, or direction of rotation, viewing the end of the shaft. With pin #2 open, CW
rotation results in a positive velocity output. When pin #2 is grounded, CCW rotation results in a positive velocity output.

Documents

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Wheel Speed Sensor Datasheet

The Wheel Speed Sensor Assembly is a rotation sensor mounted outboard of a wheel...