Excavator Hydraulic Pump Control for Smooth Actuator Startup
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Solution Overview
Problem
Existing shovel controllers rapidly increase hydraulic actuator movement, causing shocks due to sudden decreases in negative control pressure during startup, leading to uncomfortable operations.
Innovation Solution
A shovel equipped with a control device that uses a negative control pressure sensor and energy-saving control to regulate the hydraulic pump's discharge quantity, smoothing the transition of hydraulic oil flow rates to prevent sudden changes and shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the controller rapidly increases the discharge quantity when the negative control pressure suddenly decreases during hydraulic actuator startup, then the hydraulic actuator responds quickly, but a shock is caused due to abrupt movement
Solution Approach 1:
The control device performs preliminary action by detecting the startup state of the hydraulic actuator in advance and proactively limiting the increase rate of the discharge quantity command value before the shock occurs. This prevents the abrupt pressure changes that cause shock while still enabling quick response, resolving the contradiction between speed and harmful effects
Solution Approach 2:
The control device dynamically adjusts the discharge quantity command value based on the operational state of the hydraulic actuator. During startup, it limits the increase rate to prevent shock; during normal operation, it allows faster response. This dynamic adaptation resolves the contradiction by applying different control strategies to different operational phases
Data Source
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AI summary
A shovel (100) includes a lower traveling structure (1), an upper swing structure (3) swingably mounted on the lower traveling structure (1), an engine (11) mounted on the upper swing structure (3), a main pump (14) configured to be driven by the engine (11), a control pressure sensor (19) serving as a negative control pressure sensor, and a controller (30) configured to determine a command value (Qn) by energy saving control and to control the flow rate of hydraulic oil discharged by the main pump (14) according to the command value (Qn). The controller (30) is configured to control the command value (Qn).