Utility vehicles used in a high-voltage environment require modulating remote controls. These controls must provide the workmen with good control performance, and it is usually desirable that they maintain maximum dielectric strength, and have no mechanical problems. We believe control flexibility is maximized if the control function requires no mechanical interconnection between the controller and the maneuverable boom.
This paper presents design considerations for our newest modulating remote control available and gives solutions to these problems. The use of a radio to control electrohydraulic proportional valves provides the most flexible control system available for utility vehicles. Five essential parameters are considered: dielectric strength, payload, mechanical take-up reels, control system performance, and control system reliability. Dielectric strength for the radio-controlled vehicle is a function of the fiberglass boom. Since there are no mechanical devices required through the boom for controls, many potential parallel dielectric leakage paths are eliminated. The boom tare weight is also reduced enabling the bucket truck user to have increased payload capability. Mechanical take-up reels for controls are eliminated. The control system performance using electrohydraulic proportional valves is extremely smooth, with resolution (threshold) of less than 2% of rated signal. System reliability is obtained by simplicity of design with a built-in security system to protect the radio from other radios and stray signals. Also included in the radio-controlled system is a redundant electrical control from the base station of the vehicle plus override capability. The system is totally secure and provides numerous failsafe features.
