Abstract: An accessible pedestrian pushbutton station. The station includes an articulating rear mounting structure to facilitate accurate positioning of the station on either a curved or flat surface. Additionally, slots in the rear mounting structure allow for minor positional adjustments during installation. The crossing direction arrow is easily repositioned on the front of the station without disassembling the housing. After removing the screw-mounted arrow, the plunger can be turned clockwise or counter-clockwise using only a flat-head screw driver. The plunger is balanced between oppositely biased springs. The spring-balanced plunger indirectly actuates an offset piezo bender using a flexible spring actuator and a second, offset stem bumper. This protects the piezo bender from direct pressure and potential damage. The station includes an internal speaker and the housing includes bilateral sound vents to project the sound emitted by the speaker. Baffles may be inserted in one or both of the sound vents.

Abstract: An accessible pedestrian pushbutton station. The station includes an articulating rear mounting structure to facilitate accurate positioning of the station on either a curved or flat surface. Additionally, slots in the rear mounting structure allow for minor positional adjustments during installation. The crossing direction arrow is easily repositioned on the front of the station without disassembling the housing. After removing the screw-mounted arrow, the plunger can be turned clockwise or counter-clockwise using only a flat-head screw driver. The plunger is balanced between oppositely biased springs. The spring-balanced plunger indirectly actuates an offset piezo bender using a flexible spring actuator and a second, offset stem bumper. This protects the piezo bender from direct pressure and potential damage. The station includes an internal speaker and the housing includes bilateral sound vents to project the sound emitted by the speaker. Baffles may be inserted in one or both of the sound vents.

Abstract: Methods and systems are provided for conflict monitoring and error detection in accessible pedestrian signal systems. A primary conflict monitor and error detector is configured to control output of audible and vibrotactile pedestrian signal indications. The primary conflict monitor and error detector monitors the current traffic state, and verifies audio and vibrotactile control signals against the current traffic state and user settings to determine whether to enable output of audible and vibrotactile pedestrian signal indications. The primary conflict monitor and error detector may transmit information about the audio and vibrotactile control signals to a secondary conflict monitor and error detector, which verifies the information received against the current traffic state and user settings, and inhibits output of audible and vibrotactile pedestrian signal indications in the event of a detected conflict or error.

Abstract: A waveguide for projecting a longitudinal acoustic wave of wavelength .lambda. from an ultrasound energy source toward a target area. The waveguide has at least one tubular channel. The channel has inwardly tapered, conical inlet and outlet ports separated by a venturi. The inlet port taper defines a sharply rimmed entry orifice around the inlet port. A separation distance equal to one wavelength .lambda. is maintained between the source and the waveguide's inlet port. The waveguide shears off a cross-section of the wave emitted by the energy source and ejects it at accelerated velocity toward the target area. The channel has a length L and the venturi has a diameter D, such that the waveguide has an emitted beam angle equal to 2 (tan.sup.-1 (D/L)). Preferably, a plurality of tubular channels are aligned concentrically around and longitudinally parallel to the one tubular channel, each channel having a selected length and a selected diameter.