From c5f06845c2b5eb3242654451ca640d615ac8362e Mon Sep 17 00:00:00 2001 From: Paul Guenette Date: Mon, 25 Mar 2019 20:04:45 +0100 Subject: [PATCH] Allow for regen current before braking --- Firmware/MotorControl/low_level.cpp | 8 ++++---- Firmware/MotorControl/odrive_main.h | 1 + 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/Firmware/MotorControl/low_level.cpp b/Firmware/MotorControl/low_level.cpp index 82e54049..2b834e55 100644 --- a/Firmware/MotorControl/low_level.cpp +++ b/Firmware/MotorControl/low_level.cpp @@ -585,10 +585,10 @@ void update_brake_current() { Ibus_sum += axes[i]->motor_.current_control_.Ibus; } } - float brake_current = -Ibus_sum; - // Clip negative values to 0.0f - if (brake_current < 0.0f) brake_current = 0.0f; - float brake_duty = brake_current * board_config.brake_resistance / vbus_voltage; + + // Don't start braking until -Ibus > regen_current_allowed + float brake_current = std::max(-Ibus_sum - board_config.max_regen_current, 0.0f); + float brake_duty = std::max(brake_current * std::abs(board_config.brake_resistance) / vbus_voltage, 0.0f); // Duty limit at 90% to allow bootstrap caps to charge // If brake_duty is NaN, this expression will also evaluate to false diff --git a/Firmware/MotorControl/odrive_main.h b/Firmware/MotorControl/odrive_main.h index 8bff6d81..d8e569da 100644 --- a/Firmware/MotorControl/odrive_main.h +++ b/Firmware/MotorControl/odrive_main.h @@ -71,6 +71,7 @@ struct BoardConfig_t { bool enable_uart = true; bool enable_i2c_instead_of_can = false; bool enable_ascii_protocol_on_usb = true; + float max_regen_current = 0.0f; #if HW_VERSION_MAJOR == 3 && HW_VERSION_MINOR >= 5 && HW_VERSION_VOLTAGE >= 48 float brake_resistance = 2.0f; // [ohm] #else